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Posted to notifications@skywalking.apache.org by ke...@apache.org on 2020/08/21 10:26:46 UTC

[skywalking] branch master updated: Remove style-check exception for logger (#5363)

This is an automated email from the ASF dual-hosted git repository.

kezhenxu94 pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/skywalking.git


The following commit(s) were added to refs/heads/master by this push:
     new 5bfac1b  Remove style-check exception for logger (#5363)
5bfac1b is described below

commit 5bfac1b50f79d544b98bfe4b20f7db165badce52
Author: Lu Jiajing <lu...@gmail.com>
AuthorDate: Fri Aug 21 18:26:25 2020 +0800

    Remove style-check exception for logger (#5363)
---
 apm-checkstyle/checkStyle.xml                      |  2 +-
 .../skywalking/apm/util/ConfigInitializer.java     |  3 --
 .../apm/agent/core/boot/AgentPackagePath.java      |  8 ++--
 .../apm/agent/core/boot/ServiceManager.java        | 10 ++---
 .../agent/core/conf/SnifferConfigInitializer.java  | 18 ++++-----
 .../apm/agent/core/context/ContextManager.java     |  6 +--
 .../apm/agent/core/context/TracingContext.java     |  4 +-
 .../apm/agent/core/jvm/JVMMetricsSender.java       |  4 +-
 .../skywalking/apm/agent/core/jvm/JVMService.java  |  8 ++--
 .../apm/agent/core/meter/MeterSender.java          | 10 ++---
 .../apm/agent/core/meter/MeterService.java         |  6 +--
 .../core/meter/transform/GaugeTransformer.java     |  4 +-
 .../plugin/AbstractClassEnhancePluginDefine.java   | 10 ++---
 .../core/plugin/InstrumentDebuggingClass.java      |  8 ++--
 .../apm/agent/core/plugin/PluginBootstrap.java     | 10 ++---
 .../apm/agent/core/plugin/PluginCfg.java           |  4 +-
 .../agent/core/plugin/PluginResourcesResolver.java |  6 +--
 .../plugin/bootstrap/BootstrapInstrumentBoost.java |  2 +-
 .../bytebuddy/CacheableTransformerDecorator.java   |  6 +--
 .../enhance/ClassEnhancePluginDefine.java          |  2 +-
 .../interceptor/enhance/ConstructorInter.java      |  4 +-
 .../interceptor/enhance/InstMethodsInter.java      |  8 ++--
 .../enhance/InstMethodsInterWithOverrideArgs.java  |  8 ++--
 .../interceptor/enhance/StaticMethodsInter.java    |  8 ++--
 .../StaticMethodsInterWithOverrideArgs.java        |  8 ++--
 .../core/plugin/jdk9module/JDK9ModuleExporter.java |  2 +-
 .../agent/core/plugin/loader/AgentClassLoader.java |  8 ++--
 .../core/plugin/match/ProtectiveShieldMatcher.java |  6 +--
 .../agent/core/profile/ProfileSnapshotSender.java  |  8 ++--
 .../core/profile/ProfileTaskChannelService.java    | 12 +++---
 .../core/profile/ProfileTaskExecutionService.java  |  4 +-
 .../apm/agent/core/profile/ProfileThread.java      |  4 +-
 .../apm/agent/core/remote/AgentIDDecorator.java    |  4 +-
 .../apm/agent/core/remote/GRPCChannelManager.java  | 18 ++++-----
 .../agent/core/remote/GRPCStreamServiceStatus.java |  4 +-
 .../agent/core/remote/ServiceManagementClient.java |  8 ++--
 .../core/remote/TraceSegmentServiceClient.java     | 18 ++++-----
 .../apm/agent/core/sampling/SamplingService.java   |  6 +--
 .../apm/agent/core/util/CustomizeExpression.java   | 10 ++---
 .../skywalking/apm/agent/SkyWalkingAgent.java      | 26 ++++++------
 .../plugin/avro/AbstractRequestInterceptor.java    |  4 +-
 .../v5/TransportProxyClientInterceptor.java        |  4 +-
 .../RestHighLevelClientConInterceptor.java         |  2 +-
 .../v3/interceptor/v30/MongoDBInterceptor.java     |  6 +--
 .../v37/MongoDBClientDelegateInterceptor.java      |  6 +--
 .../v37/MongoDBOperationExecutorInterceptor.java   |  6 +--
 .../redisson/v3/ConnectionManagerInterceptor.java  |  6 +--
 .../v3/RedisConnectionMethodInterceptor.java       |  4 +-
 .../activation/trace/TraceContextInterceptor.java  |  4 +-
 .../customize/conf/CustomizeConfiguration.java     |  8 ++--
 .../loader/CustomizeInstrumentationLoader.java     |  4 +-
 .../plugin/zookeeper/ClientCnxnInterceptor.java    |  6 +--
 .../agent/core/kafka/KafkaJVMMetricsSender.java    |  6 +--
 .../apm/agent/core/kafka/KafkaMeterSender.java     |  6 +--
 .../core/kafka/KafkaProfileSnapshotSender.java     |  6 +--
 .../kafka/KafkaServiceManagementServiceClient.java |  8 ++--
 .../core/kafka/KafkaTraceSegmentServiceClient.java |  8 ++--
 .../analyzer/provider/jvm/JVMSourceDispatcher.java |  2 +-
 .../exporter/provider/grpc/GRPCExporter.java       | 10 ++---
 .../oap/server/core/alarm/provider/AlarmCore.java  |  4 +-
 .../oap/server/core/alarm/provider/Threshold.java  |  4 +-
 .../core/alarm/provider/WebhookCallback.java       | 10 ++---
 .../cluster/plugin/etcd/EtcdCoordinator.java       |  4 +-
 .../ClusterModuleStandaloneProvider.java           |  2 +-
 .../zookeeper/ClusterModuleZookeeperProvider.java  |  4 +-
 .../plugin/zookeeper/ZookeeperCoordinator.java     |  2 +-
 .../configuration/api/ConfigWatcherRegister.java   | 10 ++---
 .../etcd/EtcdConfigWatcherRegister.java            |  6 +--
 .../etcd/EtcdConfigurationProvider.java            |  4 +-
 .../oap/server/configuration/etcd/EtcdUtils.java   |  6 +--
 .../etcd/ITEtcdConfigurationTest.java              |  6 +--
 .../grpc/GRPCConfigWatcherRegister.java            |  4 +-
 .../skywalking/oap/server/core/WorkPath.java       |  4 +-
 .../core/alarm/AlarmStandardPersistence.java       |  6 +--
 .../server/core/analysis/DispatcherManager.java    |  4 +-
 .../analysis/worker/RecordPersistentWorker.java    |  4 +-
 .../config/ComponentLibraryCatalogService.java     |  4 +-
 .../server/core/remote/RemoteSenderService.java    |  4 +-
 .../server/core/remote/RemoteServiceHandler.java   |  8 ++--
 .../core/remote/client/GRPCRemoteClient.java       | 12 +++---
 .../core/remote/client/RemoteClientManager.java    | 20 +++++-----
 .../remote/health/HealthCheckServiceHandler.java   |  6 +--
 .../core/remote/selector/ForeverFirstSelector.java |  6 +--
 .../server/core/worker/WorkerInstancesService.java |  4 +-
 .../oap/server/library/client/grpc/GRPCClient.java |  4 +-
 .../client/jdbc/hikaricp/JDBCHikariCPClient.java   |  8 ++--
 .../elasticsearch/ITElasticSearchClient.java       | 10 ++---
 .../oap/server/library/module/BootstrapFlow.java   |  4 +-
 .../oap/server/library/module/ModuleDefine.java    |  7 ++--
 .../oap/server/library/server/grpc/GRPCServer.java | 10 ++---
 .../library/server/jetty/JettyJsonHandler.java     |  6 +--
 .../server/library/server/jetty/JettyServer.java   | 12 +++---
 .../oap/server/library/util/TimestampUtils.java    |  4 +-
 .../oap/query/graphql/GraphQLQueryHandler.java     |  6 +--
 .../envoy/AccessLogServiceGRPCHandler.java         | 10 ++---
 .../oap/server/receiver/envoy/als/Fetcher.java     |  6 +--
 .../envoy/als/K8sALSServiceMeshHTTPAnalysis.java   | 24 +++++------
 .../server/receiver/jaeger/JaegerGRPCHandler.java  |  8 ++--
 .../clr/provider/handler/CLRSourceDispatcher.java  |  2 +-
 .../provider/IstioTelemetryGRPCHandler.java        |  8 ++--
 .../aop/server/receiver/mesh/MeshGRPCHandler.java  |  8 ++--
 .../analysis/cache/caffeine/CaffeineSpanCache.java |  6 +--
 .../zipkin/handler/SpanV1JettyHandler.java         |  4 +-
 .../zipkin/handler/SpanV2JettyHandler.java         |  4 +-
 .../elasticsearch/base/BatchProcessEsDAO.java      |  2 +-
 .../server/storage/plugin/jdbc/SQLExecutor.java    |  4 +-
 .../jdbc/h2/dao/H2NetworkAddressAliasDAO.java      |  4 +-
 skywalking-ui                                      |  2 +-
 .../test/helper/AbstractRunningGenerator.java      |  4 +-
 .../test/helper/DockerComposeRunningGenerator.java |  6 +--
 .../helper/DockerContainerRunningGenerator.java    |  4 +-
 .../activemq/controller/CaseController.java        | 14 +++----
 .../testcase/avro/controller/CaseController.java   |  2 +-
 .../testcase/canal/controller/CaseController.java  |  6 +--
 .../cassandra/controller/CaseController.java       | 46 +++++++++++-----------
 .../customize/controller/CustomizeController.java  |  4 +-
 .../apm/testcase/elasticjob/Application.java       |  4 +-
 .../apm/testcase/elasticjob/job/DemoSimpleJob.java |  4 +-
 .../elasticsearch/controller/CaseController.java   | 10 ++---
 .../elasticsearch/RestHighLevelClientCase.java     | 16 ++++----
 .../elasticsearch/TransportClientCase.java         |  6 +--
 .../elasticsearch/controller/CaseController.java   |  2 +-
 .../elasticsearch/controller/CaseController.java   | 22 +++++------
 .../testcase/feign/controller/CaseController.java  |  4 +-
 .../testcase/grpc/consumr/ConsumerInterceptor.java | 28 ++++++-------
 .../testcase/grpc/controller/CaseController.java   |  8 ++--
 .../provider/interceptor/ProviderInterceptor.java  | 18 ++++-----
 .../grpc/provider/service/GreeterServiceImpl.java  |  6 +--
 .../testcase/httpasyncclient/FrontController.java  | 10 ++---
 .../hystrix/controller/CaseController.java         | 16 ++++----
 .../testcase/hystrix/controller/TestACommand.java  | 10 ++---
 .../testcase/hystrix/controller/TestBCommand.java  | 10 ++---
 .../jdkhttp/controller/CaseController.java         |  2 +-
 .../testcase/kafka/controller/CaseController.java  | 12 +++---
 .../apm/testcase/mariadb/Application.java          |  4 +-
 .../apm/testcase/mariadb/MariadbConfig.java        |  4 +-
 .../apm/testcase/mariadb/SQLExecutor.java          |  4 +-
 .../mariadb/controller/CaseController.java         |  4 +-
 .../skywalking/apm/testcase/mysql/MysqlConfig.java |  4 +-
 .../testcase/mysql/controller/CaseController.java  |  4 +-
 .../testcase/oracle/controller/CaseController.java | 12 +++---
 .../postgresql/controller/CaseController.java      | 12 +++---
 .../postgresql/controller/CaseController.java      | 12 +++---
 .../testcase/pulsar/controller/CaseController.java |  8 ++--
 .../apm/testcase/quasar/Application.java           |  4 +-
 .../testcase/quasar/controller/CaseController.java |  4 +-
 .../rabbitmq/controller/CaseController.java        | 20 +++++-----
 .../testcase/resttemplate/FrontController.java     |  4 +-
 .../testcase/retransform_class/Application.java    |  2 +-
 .../retransform_class/RetransformUtil.java         |  6 +--
 .../controller/CaseController.java                 |  6 +--
 .../testcase/solrj/controller/CaseController.java  |  2 +-
 .../resttemplate/RestTemplateController.java       |  4 +-
 .../resttemplate/RestTemplateController.java       |  4 +-
 .../resttemplate/RestTemplateController.java       | 10 ++---
 .../testcase/feign/controller/CaseController.java  |  4 +-
 .../testcase/feign/controller/CaseController.java  |  4 +-
 .../testcase/zookeeper/controller/Zookeeper.java   |  4 +-
 .../zookeeper/controller/ZookeeperController.java  |  4 +-
 159 files changed, 572 insertions(+), 574 deletions(-)

diff --git a/apm-checkstyle/checkStyle.xml b/apm-checkstyle/checkStyle.xml
index 9958d8f..de196c1 100755
--- a/apm-checkstyle/checkStyle.xml
+++ b/apm-checkstyle/checkStyle.xml
@@ -79,7 +79,7 @@
         <!--Checks that long constants are defined with an upper ell-->
         <module name="UpperEll"/>
         <module name="ConstantName">
-            <property name="format" value="(^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$)|(^logger)"/>
+            <property name="format" value="(^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$)"/>
         </module>
         <!--Checks that local, non-final variable names conform to producerGroup format specified by the format property-->
         <module name="LocalVariableName"/>
diff --git a/apm-commons/apm-util/src/main/java/org/apache/skywalking/apm/util/ConfigInitializer.java b/apm-commons/apm-util/src/main/java/org/apache/skywalking/apm/util/ConfigInitializer.java
index 909883b..163f46b 100644
--- a/apm-commons/apm-util/src/main/java/org/apache/skywalking/apm/util/ConfigInitializer.java
+++ b/apm-commons/apm-util/src/main/java/org/apache/skywalking/apm/util/ConfigInitializer.java
@@ -28,15 +28,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Properties;
-import java.util.logging.Logger;
 
 /**
  * Init a class's static fields by a {@link Properties}, including static fields and static inner classes.
  * <p>
  */
 public class ConfigInitializer {
-    private static final Logger logger = Logger.getLogger(ConfigInitializer.class.getName());
-
     public static void initialize(Properties properties, Class<?> rootConfigType) throws IllegalAccessException {
         initNextLevel(properties, rootConfigType, new ConfigDesc());
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/AgentPackagePath.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/AgentPackagePath.java
index 105cfde..611def0 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/AgentPackagePath.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/AgentPackagePath.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * mechanism fails, the agent will exit directly.
  */
 public class AgentPackagePath {
-    private static final ILog logger = LogManager.getLogger(AgentPackagePath.class);
+    private static final ILog LOGGER = LogManager.getLogger(AgentPackagePath.class);
 
     private static File AGENT_PACKAGE_PATH;
 
@@ -53,7 +53,7 @@ public class AgentPackagePath {
         if (resource != null) {
             String urlString = resource.toString();
 
-            logger.debug("The beacon class location is {}.", urlString);
+            LOGGER.debug("The beacon class location is {}.", urlString);
 
             int insidePathIndex = urlString.indexOf('!');
             boolean isInJar = insidePathIndex > -1;
@@ -64,7 +64,7 @@ public class AgentPackagePath {
                 try {
                     agentJarFile = new File(new URL(urlString).toURI());
                 } catch (MalformedURLException | URISyntaxException e) {
-                    logger.error(e, "Can not locate agent jar file by url:" + urlString);
+                    LOGGER.error(e, "Can not locate agent jar file by url:" + urlString);
                 }
                 if (agentJarFile.exists()) {
                     return agentJarFile.getParentFile();
@@ -77,7 +77,7 @@ public class AgentPackagePath {
             }
         }
 
-        logger.error("Can not locate agent jar file.");
+        LOGGER.error("Can not locate agent jar file.");
         throw new AgentPackageNotFoundException("Can not locate agent jar file.");
     }
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
index 97cc0e5..46158cd 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
@@ -34,7 +34,7 @@ import org.apache.skywalking.apm.agent.core.plugin.loader.AgentClassLoader;
 public enum ServiceManager {
     INSTANCE;
 
-    private static final ILog logger = LogManager.getLogger(ServiceManager.class);
+    private static final ILog LOGGER = LogManager.getLogger(ServiceManager.class);
     private Map<Class, BootService> bootedServices = Collections.emptyMap();
 
     public void boot() {
@@ -50,7 +50,7 @@ public enum ServiceManager {
             try {
                 service.shutdown();
             } catch (Throwable e) {
-                logger.error(e, "ServiceManager try to shutdown [{}] fail.", service.getClass().getName());
+                LOGGER.error(e, "ServiceManager try to shutdown [{}] fail.", service.getClass().getName());
             }
         }
     }
@@ -103,7 +103,7 @@ public enum ServiceManager {
             try {
                 service.prepare();
             } catch (Throwable e) {
-                logger.error(e, "ServiceManager try to pre-start [{}] fail.", service.getClass().getName());
+                LOGGER.error(e, "ServiceManager try to pre-start [{}] fail.", service.getClass().getName());
             }
         }
     }
@@ -113,7 +113,7 @@ public enum ServiceManager {
             try {
                 service.boot();
             } catch (Throwable e) {
-                logger.error(e, "ServiceManager try to start [{}] fail.", service.getClass().getName());
+                LOGGER.error(e, "ServiceManager try to start [{}] fail.", service.getClass().getName());
             }
         }
     }
@@ -123,7 +123,7 @@ public enum ServiceManager {
             try {
                 service.onComplete();
             } catch (Throwable e) {
-                logger.error(e, "Service [{}] AfterBoot process fails.", service.getClass().getName());
+                LOGGER.error(e, "Service [{}] AfterBoot process fails.", service.getClass().getName());
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
index 69042c8..d5fbd6a 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/conf/SnifferConfigInitializer.java
@@ -40,7 +40,7 @@ import org.apache.skywalking.apm.util.StringUtil;
  * The <code>SnifferConfigInitializer</code> initializes all configs in several way.
  */
 public class SnifferConfigInitializer {
-    private static final ILog logger = LogManager.getLogger(SnifferConfigInitializer.class);
+    private static final ILog LOGGER = LogManager.getLogger(SnifferConfigInitializer.class);
     private static final String SPECIFIED_CONFIG_PATH = "skywalking_config";
     private static final String DEFAULT_CONFIG_FILE_NAME = "/config/agent.config";
     private static final String ENV_KEY_PREFIX = "skywalking.";
@@ -68,24 +68,24 @@ public class SnifferConfigInitializer {
             }
 
         } catch (Exception e) {
-            logger.error(e, "Failed to read the config file, skywalking is going to run in default config.");
+            LOGGER.error(e, "Failed to read the config file, skywalking is going to run in default config.");
         }
 
         try {
             overrideConfigBySystemProp();
         } catch (Exception e) {
-            logger.error(e, "Failed to read the system properties.");
+            LOGGER.error(e, "Failed to read the system properties.");
         }
 
         agentOptions = StringUtil.trim(agentOptions, ',');
         if (!StringUtil.isEmpty(agentOptions)) {
             try {
                 agentOptions = agentOptions.trim();
-                logger.info("Agent options is {}.", agentOptions);
+                LOGGER.info("Agent options is {}.", agentOptions);
 
                 overrideConfigByAgentOptions(agentOptions);
             } catch (Exception e) {
-                logger.error(e, "Failed to parse the agent options, val is {}.", agentOptions);
+                LOGGER.error(e, "Failed to parse the agent options, val is {}.", agentOptions);
             }
         }
 
@@ -98,7 +98,7 @@ public class SnifferConfigInitializer {
             throw new ExceptionInInitializerError("`collector.backend_service` is missing.");
         }
         if (Config.Plugin.PEER_MAX_LENGTH <= 3) {
-            logger.warn(
+            LOGGER.warn(
                 "PEER_MAX_LENGTH configuration:{} error, the default value of 200 will be used.",
                 Config.Plugin.PEER_MAX_LENGTH
             );
@@ -115,13 +115,13 @@ public class SnifferConfigInitializer {
      */
     public static void initializeConfig(Class configClass) {
         if (AGENT_SETTINGS == null) {
-            logger.error("Plugin configs have to be initialized after core config initialization.");
+            LOGGER.error("Plugin configs have to be initialized after core config initialization.");
             return;
         }
         try {
             ConfigInitializer.initialize(AGENT_SETTINGS, configClass);
         } catch (IllegalAccessException e) {
-            logger.error(e,
+            LOGGER.error(e,
                          "Failed to set the agent settings {}"
                              + " to Config={} ",
                          AGENT_SETTINGS, configClass
@@ -198,7 +198,7 @@ public class SnifferConfigInitializer {
 
         if (configFile.exists() && configFile.isFile()) {
             try {
-                logger.info("Config file found in {}.", configFile);
+                LOGGER.info("Config file found in {}.", configFile);
 
                 return new InputStreamReader(new FileInputStream(configFile), StandardCharsets.UTF_8);
             } catch (FileNotFoundException e) {
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
index 46f7dc0..39190c7 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/ContextManager.java
@@ -38,7 +38,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Agent.OPERATION_N
  * <p> Also, {@link ContextManager} delegates to all {@link AbstractTracerContext}'s major methods.
  */
 public class ContextManager implements BootService {
-    private static final ILog logger = LogManager.getLogger(ContextManager.class);
+    private static final ILog LOGGER = LogManager.getLogger(ContextManager.class);
     private static ThreadLocal<AbstractTracerContext> CONTEXT = new ThreadLocal<AbstractTracerContext>();
     private static ThreadLocal<RuntimeContext> RUNTIME_CONTEXT = new ThreadLocal<RuntimeContext>();
     private static ContextManagerExtendService EXTEND_SERVICE;
@@ -47,8 +47,8 @@ public class ContextManager implements BootService {
         AbstractTracerContext context = CONTEXT.get();
         if (context == null) {
             if (StringUtil.isEmpty(operationName)) {
-                if (logger.isDebugEnable()) {
-                    logger.debug("No operation name, ignore this trace.");
+                if (LOGGER.isDebugEnable()) {
+                    LOGGER.debug("No operation name, ignore this trace.");
                 }
                 context = new IgnoredTracerContext();
             } else {
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
index d803084..5920f3b 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
@@ -55,7 +55,7 @@ import org.apache.skywalking.apm.util.StringUtil;
  * ContextCarrier} or {@link ContextSnapshot}.
  */
 public class TracingContext implements AbstractTracerContext {
-    private static final ILog logger = LogManager.getLogger(TracingContext.class);
+    private static final ILog LOGGER = LogManager.getLogger(TracingContext.class);
     private long lastWarningTimestamp = 0;
 
     /**
@@ -559,7 +559,7 @@ public class TracingContext implements AbstractTracerContext {
         if (spanIdGenerator >= Config.Agent.SPAN_LIMIT_PER_SEGMENT) {
             long currentTimeMillis = System.currentTimeMillis();
             if (currentTimeMillis - lastWarningTimestamp > 30 * 1000) {
-                logger.warn(
+                LOGGER.warn(
                     new RuntimeException("Shadow tracing context. Thread dump"),
                     "More than {} spans required to create", Config.Agent.SPAN_LIMIT_PER_SEGMENT
                 );
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMMetricsSender.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMMetricsSender.java
index 501f01a..bbf084c 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMMetricsSender.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMMetricsSender.java
@@ -41,7 +41,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Collector.GRPC_UP
 
 @DefaultImplementor
 public class JVMMetricsSender implements BootService, Runnable, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(JVMMetricsSender.class);
+    private static final ILog LOGGER = LogManager.getLogger(JVMMetricsSender.class);
 
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
     private volatile JVMMetricReportServiceGrpc.JVMMetricReportServiceBlockingStub stub = null;
@@ -83,7 +83,7 @@ public class JVMMetricsSender implements BootService, Runnable, GRPCChannelListe
                     ServiceManager.INSTANCE.findService(CommandService.class).receiveCommand(commands);
                 }
             } catch (Throwable t) {
-                logger.error(t, "send JVM metrics to Collector fail.");
+                LOGGER.error(t, "send JVM metrics to Collector fail.");
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMService.java
index 542d7f8..736fccf 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/JVMService.java
@@ -42,7 +42,7 @@ import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
  */
 @DefaultImplementor
 public class JVMService implements BootService, Runnable {
-    private static final ILog logger = LogManager.getLogger(JVMService.class);
+    private static final ILog LOGGER = LogManager.getLogger(JVMService.class);
     private volatile ScheduledFuture<?> collectMetricFuture;
     private volatile ScheduledFuture<?> sendMetricFuture;
     private JVMMetricsSender sender;
@@ -61,7 +61,7 @@ public class JVMService implements BootService, Runnable {
                                            new RunnableWithExceptionProtection.CallbackWhenException() {
                                                @Override
                                                public void handle(Throwable t) {
-                                                   logger.error("JVMService produces metrics failure.", t);
+                                                   LOGGER.error("JVMService produces metrics failure.", t);
                                                }
                                            }
                                        ), 0, 1, TimeUnit.SECONDS);
@@ -72,7 +72,7 @@ public class JVMService implements BootService, Runnable {
                                         new RunnableWithExceptionProtection.CallbackWhenException() {
                                             @Override
                                             public void handle(Throwable t) {
-                                                logger.error("JVMService consumes and upload failure.", t);
+                                                LOGGER.error("JVMService consumes and upload failure.", t);
                                             }
                                         }
                                     ), 0, 1, TimeUnit.SECONDS);
@@ -103,7 +103,7 @@ public class JVMService implements BootService, Runnable {
 
             sender.offer(jvmBuilder.build());
         } catch (Exception e) {
-            logger.error(e, "Collect JVM info fail.");
+            LOGGER.error(e, "Collect JVM info fail.");
         }
     }
 }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterSender.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterSender.java
index b0fa3d6..2c2d3b3 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterSender.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterSender.java
@@ -44,7 +44,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Collector.GRPC_UP
 
 @DefaultImplementor
 public class MeterSender implements BootService, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(MeterSender.class);
+    private static final ILog LOGGER = LogManager.getLogger(MeterSender.class);
 
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
 
@@ -75,8 +75,8 @@ public class MeterSender implements BootService, GRPCChannelListener {
                     @Override
                     public void onError(Throwable throwable) {
                         status.finished();
-                        if (logger.isErrorEnable()) {
-                            logger.error(throwable, "Send meters to collector fail with a grpc internal exception.");
+                        if (LOGGER.isErrorEnable()) {
+                            LOGGER.error(throwable, "Send meters to collector fail with a grpc internal exception.");
                         }
                         ServiceManager.INSTANCE.findService(GRPCChannelManager.class).reportError(throwable);
                     }
@@ -91,12 +91,12 @@ public class MeterSender implements BootService, GRPCChannelListener {
                 transform(meterMap, meterData -> reporter.onNext(meterData));
             } catch (Throwable e) {
                 if (!(e instanceof StatusRuntimeException)) {
-                    logger.error(e, "Report meters to backend fail.");
+                    LOGGER.error(e, "Report meters to backend fail.");
                     return;
                 }
                 final StatusRuntimeException statusRuntimeException = (StatusRuntimeException) e;
                 if (statusRuntimeException.getStatus().getCode() == Status.Code.UNIMPLEMENTED) {
-                    logger.warn("Backend doesn't support meter, it will be disabled");
+                    LOGGER.warn("Backend doesn't support meter, it will be disabled");
 
                     meterService.shutdown();
                 }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterService.java
index fa1b8e9..57e1193 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/MeterService.java
@@ -34,7 +34,7 @@ import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
 
 @DefaultImplementor
 public class MeterService implements BootService, Runnable {
-    private static final ILog logger = LogManager.getLogger(MeterService.class);
+    private static final ILog LOGGER = LogManager.getLogger(MeterService.class);
 
     // all meters
     private final ConcurrentHashMap<MeterId, MeterTransformer> meterMap = new ConcurrentHashMap<>();
@@ -52,7 +52,7 @@ public class MeterService implements BootService, Runnable {
             return;
         }
         if (meterMap.size() >= Config.Meter.MAX_METER_SIZE) {
-            logger.warn(
+            LOGGER.warn(
                 "Already out of the meter system max size, will not report. meter name:{}", meterTransformer.getName());
             return;
         }
@@ -72,7 +72,7 @@ public class MeterService implements BootService, Runnable {
                 new DefaultNamedThreadFactory("MeterReportService")
             ).scheduleWithFixedDelay(new RunnableWithExceptionProtection(
                 this,
-                t -> logger.error("Report meters failure.", t)
+                t -> LOGGER.error("Report meters failure.", t)
             ), 0, Config.Meter.REPORT_INTERVAL, TimeUnit.SECONDS);
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/transform/GaugeTransformer.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/transform/GaugeTransformer.java
index 1cbb842..6e8e09c 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/transform/GaugeTransformer.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/meter/transform/GaugeTransformer.java
@@ -25,7 +25,7 @@ import org.apache.skywalking.apm.network.language.agent.v3.MeterData;
 import org.apache.skywalking.apm.network.language.agent.v3.MeterSingleValue;
 
 public class GaugeTransformer extends MeterTransformer<GaugeAdapter> {
-    private static final ILog logger = LogManager.getLogger(GaugeTransformer.class);
+    private static final ILog LOGGER = LogManager.getLogger(GaugeTransformer.class);
 
     public GaugeTransformer(GaugeAdapter adapter) {
         super(adapter);
@@ -38,7 +38,7 @@ public class GaugeTransformer extends MeterTransformer<GaugeAdapter> {
         try {
             count = adapter.getCount();
         } catch (Exception e) {
-            logger.warn(e, "Cannot get the count in meter:{}", adapter.getId().getName());
+            LOGGER.warn(e, "Cannot get the count in meter:{}", adapter.getId().getName());
             return null;
         }
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
index 76cad6a..c6391ff 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/AbstractClassEnhancePluginDefine.java
@@ -36,7 +36,7 @@ import org.apache.skywalking.apm.util.StringUtil;
  * {@link ClassEnhancePluginDefine}
  */
 public abstract class AbstractClassEnhancePluginDefine {
-    private static final ILog logger = LogManager.getLogger(AbstractClassEnhancePluginDefine.class);
+    private static final ILog LOGGER = LogManager.getLogger(AbstractClassEnhancePluginDefine.class);
 
     /**
      * Main entrance of enhancing the class.
@@ -52,11 +52,11 @@ public abstract class AbstractClassEnhancePluginDefine {
         String interceptorDefineClassName = this.getClass().getName();
         String transformClassName = typeDescription.getTypeName();
         if (StringUtil.isEmpty(transformClassName)) {
-            logger.warn("classname of being intercepted is not defined by {}.", interceptorDefineClassName);
+            LOGGER.warn("classname of being intercepted is not defined by {}.", interceptorDefineClassName);
             return null;
         }
 
-        logger.debug("prepare to enhance class {} by {}.", transformClassName, interceptorDefineClassName);
+        LOGGER.debug("prepare to enhance class {} by {}.", transformClassName, interceptorDefineClassName);
 
         /**
          * find witness classes for enhance class
@@ -65,7 +65,7 @@ public abstract class AbstractClassEnhancePluginDefine {
         if (witnessClasses != null) {
             for (String witnessClass : witnessClasses) {
                 if (!WitnessClassFinder.INSTANCE.exist(witnessClass, classLoader)) {
-                    logger.warn("enhance class {} by plugin {} is not working. Because witness class {} is not existed.", transformClassName, interceptorDefineClassName, witnessClass);
+                    LOGGER.warn("enhance class {} by plugin {} is not working. Because witness class {} is not existed.", transformClassName, interceptorDefineClassName, witnessClass);
                     return null;
                 }
             }
@@ -77,7 +77,7 @@ public abstract class AbstractClassEnhancePluginDefine {
         DynamicType.Builder<?> newClassBuilder = this.enhance(typeDescription, builder, classLoader, context);
 
         context.initializationStageCompleted();
-        logger.debug("enhance class {} by {} completely.", transformClassName, interceptorDefineClassName);
+        LOGGER.debug("enhance class {} by {} completely.", transformClassName, interceptorDefineClassName);
 
         return newClassBuilder;
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/InstrumentDebuggingClass.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/InstrumentDebuggingClass.java
index b5244b6..bcf682b 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/InstrumentDebuggingClass.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/InstrumentDebuggingClass.java
@@ -34,7 +34,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
 public enum InstrumentDebuggingClass {
     INSTANCE;
 
-    private static final ILog logger = LogManager.getLogger(InstrumentDebuggingClass.class);
+    private static final ILog LOGGER = LogManager.getLogger(InstrumentDebuggingClass.class);
     private File debuggingClassesRootPath;
 
     public void log(DynamicType dynamicType) {
@@ -54,17 +54,17 @@ public enum InstrumentDebuggingClass {
                             debuggingClassesRootPath.mkdir();
                         }
                     } catch (AgentPackageNotFoundException e) {
-                        logger.error(e, "Can't find the root path for creating /debugging folder.");
+                        LOGGER.error(e, "Can't find the root path for creating /debugging folder.");
                     }
                 }
 
                 try {
                     dynamicType.saveIn(debuggingClassesRootPath);
                 } catch (IOException e) {
-                    logger.error(e, "Can't save class {} to file." + dynamicType.getTypeDescription().getActualName());
+                    LOGGER.error(e, "Can't save class {} to file." + dynamicType.getTypeDescription().getActualName());
                 }
             } catch (Throwable t) {
-                logger.error(t, "Save debugging classes fail.");
+                LOGGER.error(t, "Save debugging classes fail.");
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginBootstrap.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginBootstrap.java
index 2ab7c6c..7d54eeb 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginBootstrap.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginBootstrap.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * definitions.
  */
 public class PluginBootstrap {
-    private static final ILog logger = LogManager.getLogger(PluginBootstrap.class);
+    private static final ILog LOGGER = LogManager.getLogger(PluginBootstrap.class);
 
     /**
      * load all plugins.
@@ -45,7 +45,7 @@ public class PluginBootstrap {
         List<URL> resources = resolver.getResources();
 
         if (resources == null || resources.size() == 0) {
-            logger.info("no plugin files (skywalking-plugin.def) found, continue to start application.");
+            LOGGER.info("no plugin files (skywalking-plugin.def) found, continue to start application.");
             return new ArrayList<AbstractClassEnhancePluginDefine>();
         }
 
@@ -53,7 +53,7 @@ public class PluginBootstrap {
             try {
                 PluginCfg.INSTANCE.load(pluginUrl.openStream());
             } catch (Throwable t) {
-                logger.error(t, "plugin file [{}] init failure.", pluginUrl);
+                LOGGER.error(t, "plugin file [{}] init failure.", pluginUrl);
             }
         }
 
@@ -62,12 +62,12 @@ public class PluginBootstrap {
         List<AbstractClassEnhancePluginDefine> plugins = new ArrayList<AbstractClassEnhancePluginDefine>();
         for (PluginDefine pluginDefine : pluginClassList) {
             try {
-                logger.debug("loading plugin class {}.", pluginDefine.getDefineClass());
+                LOGGER.debug("loading plugin class {}.", pluginDefine.getDefineClass());
                 AbstractClassEnhancePluginDefine plugin = (AbstractClassEnhancePluginDefine) Class.forName(pluginDefine.getDefineClass(), true, AgentClassLoader
                     .getDefault()).newInstance();
                 plugins.add(plugin);
             } catch (Throwable t) {
-                logger.error(t, "load plugin [{}] failure.", pluginDefine.getDefineClass());
+                LOGGER.error(t, "load plugin [{}] failure.", pluginDefine.getDefineClass());
             }
         }
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginCfg.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginCfg.java
index 1fe5646..b482546 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginCfg.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginCfg.java
@@ -32,7 +32,7 @@ import java.util.List;
 public enum PluginCfg {
     INSTANCE;
 
-    private static final ILog logger = LogManager.getLogger(PluginCfg.class);
+    private static final ILog LOGGER = LogManager.getLogger(PluginCfg.class);
 
     private List<PluginDefine> pluginClassList = new ArrayList<PluginDefine>();
     private PluginSelector pluginSelector = new PluginSelector();
@@ -49,7 +49,7 @@ public enum PluginCfg {
                     PluginDefine plugin = PluginDefine.build(pluginDefine);
                     pluginClassList.add(plugin);
                 } catch (IllegalPluginDefineException e) {
-                    logger.error(e, "Failed to format plugin({}) define.", pluginDefine);
+                    LOGGER.error(e, "Failed to format plugin({}) define.", pluginDefine);
                 }
             }
             pluginClassList = pluginSelector.select(pluginClassList);
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginResourcesResolver.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginResourcesResolver.java
index 15df883..6de75a3 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginResourcesResolver.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginResourcesResolver.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.agent.core.plugin.loader.AgentClassLoader;
  * Use the current classloader to read all plugin define file. The file must be named 'skywalking-plugin.def'
  */
 public class PluginResourcesResolver {
-    private static final ILog logger = LogManager.getLogger(PluginResourcesResolver.class);
+    private static final ILog LOGGER = LogManager.getLogger(PluginResourcesResolver.class);
 
     public List<URL> getResources() {
         List<URL> cfgUrlPaths = new ArrayList<URL>();
@@ -42,12 +42,12 @@ public class PluginResourcesResolver {
             while (urls.hasMoreElements()) {
                 URL pluginUrl = urls.nextElement();
                 cfgUrlPaths.add(pluginUrl);
-                logger.info("find skywalking plugin define in {}", pluginUrl);
+                LOGGER.info("find skywalking plugin define in {}", pluginUrl);
             }
 
             return cfgUrlPaths;
         } catch (IOException e) {
-            logger.error("read resources failure.", e);
+            LOGGER.error("read resources failure.", e);
         }
         return null;
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java
index 79d42f5..19afeea 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bootstrap/BootstrapInstrumentBoost.java
@@ -52,7 +52,7 @@ import static net.bytebuddy.matcher.ElementMatchers.named;
  * classes into bootstrap class loader, including generated dynamic delegate classes.
  */
 public class BootstrapInstrumentBoost {
-    private static final ILog logger = LogManager.getLogger(BootstrapInstrumentBoost.class);
+    private static final ILog LOGGER = LogManager.getLogger(BootstrapInstrumentBoost.class);
 
     private static final String[] HIGH_PRIORITY_CLASSES = {
         "org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.BootstrapInterRuntimeAssist",
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/CacheableTransformerDecorator.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/CacheableTransformerDecorator.java
index 160ad38..2b39251 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/CacheableTransformerDecorator.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/bytebuddy/CacheableTransformerDecorator.java
@@ -46,7 +46,7 @@ import java.util.concurrent.ConcurrentHashMap;
  */
 public class CacheableTransformerDecorator implements AgentBuilder.TransformerDecorator {
 
-    private static final ILog logger = LogManager.getLogger(CacheableTransformerDecorator.class);
+    private static final ILog LOGGER = LogManager.getLogger(CacheableTransformerDecorator.class);
 
     private final ClassCacheMode cacheMode;
     private ClassCacheResolver cacheResolver;
@@ -163,7 +163,7 @@ public class CacheableTransformerDecorator implements AgentBuilder.TransformerDe
                     fileInputStream = new FileInputStream(cacheFile);
                     return IOUtils.toByteArray(fileInputStream);
                 } catch (IOException e) {
-                    logger.error("load class bytes from cache file failure", e);
+                    LOGGER.error("load class bytes from cache file failure", e);
                 } finally {
                     IOUtils.closeQuietly(fileInputStream);
                 }
@@ -180,7 +180,7 @@ public class CacheableTransformerDecorator implements AgentBuilder.TransformerDe
                 output = new FileOutputStream(cacheFile);
                 IOUtils.copy(new ByteArrayInputStream(classfileBuffer), output);
             } catch (IOException e) {
-                logger.error("save class bytes to cache file failure", e);
+                LOGGER.error("save class bytes to cache file failure", e);
             } finally {
                 IOUtils.closeQuietly(output);
             }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
index d3689d6..4963c7a 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ClassEnhancePluginDefine.java
@@ -52,7 +52,7 @@ import static net.bytebuddy.matcher.ElementMatchers.not;
  * instance methods, or both, {@link ClassEnhancePluginDefine} will add a field of {@link Object} type.
  */
 public abstract class ClassEnhancePluginDefine extends AbstractClassEnhancePluginDefine {
-    private static final ILog logger = LogManager.getLogger(ClassEnhancePluginDefine.class);
+    private static final ILog LOGGER = LogManager.getLogger(ClassEnhancePluginDefine.class);
 
     /**
      * New field name.
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ConstructorInter.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ConstructorInter.java
index 8a11654..e9f8f85 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ConstructorInter.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/ConstructorInter.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.ILog;
  * byte-buddy and sky-walking plugin.
  */
 public class ConstructorInter {
-    private static final ILog logger = LogManager.getLogger(ConstructorInter.class);
+    private static final ILog LOGGER = LogManager.getLogger(ConstructorInter.class);
 
     /**
      * An {@link InstanceConstructorInterceptor} This name should only stay in {@link String}, the real {@link Class}
@@ -64,7 +64,7 @@ public class ConstructorInter {
 
             interceptor.onConstruct(targetObject, allArguments);
         } catch (Throwable t) {
-            logger.error("ConstructorInter failure.", t);
+            LOGGER.error("ConstructorInter failure.", t);
         }
 
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInter.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInter.java
index b2b5db2..58f1839 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInter.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInter.java
@@ -35,7 +35,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.ILog;
  * byte-buddy and sky-walking plugin.
  */
 public class InstMethodsInter {
-    private static final ILog logger = LogManager.getLogger(InstMethodsInter.class);
+    private static final ILog LOGGER = LogManager.getLogger(InstMethodsInter.class);
 
     /**
      * An {@link InstanceMethodsAroundInterceptor} This name should only stay in {@link String}, the real {@link Class}
@@ -75,7 +75,7 @@ public class InstMethodsInter {
         try {
             interceptor.beforeMethod(targetObject, method, allArguments, method.getParameterTypes(), result);
         } catch (Throwable t) {
-            logger.error(t, "class[{}] before method[{}] intercept failure", obj.getClass(), method.getName());
+            LOGGER.error(t, "class[{}] before method[{}] intercept failure", obj.getClass(), method.getName());
         }
 
         Object ret = null;
@@ -89,14 +89,14 @@ public class InstMethodsInter {
             try {
                 interceptor.handleMethodException(targetObject, method, allArguments, method.getParameterTypes(), t);
             } catch (Throwable t2) {
-                logger.error(t2, "class[{}] handle method[{}] exception failure", obj.getClass(), method.getName());
+                LOGGER.error(t2, "class[{}] handle method[{}] exception failure", obj.getClass(), method.getName());
             }
             throw t;
         } finally {
             try {
                 ret = interceptor.afterMethod(targetObject, method, allArguments, method.getParameterTypes(), ret);
             } catch (Throwable t) {
-                logger.error(t, "class[{}] after method[{}] intercept failure", obj.getClass(), method.getName());
+                LOGGER.error(t, "class[{}] after method[{}] intercept failure", obj.getClass(), method.getName());
             }
         }
         return ret;
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInterWithOverrideArgs.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInterWithOverrideArgs.java
index 257ae60..f0cbfc5 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInterWithOverrideArgs.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/InstMethodsInterWithOverrideArgs.java
@@ -34,7 +34,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * byte-buddy and sky-walking plugin.
  */
 public class InstMethodsInterWithOverrideArgs {
-    private static final ILog logger = LogManager.getLogger(InstMethodsInterWithOverrideArgs.class);
+    private static final ILog LOGGER = LogManager.getLogger(InstMethodsInterWithOverrideArgs.class);
 
     /**
      * An {@link InstanceMethodsAroundInterceptor} This name should only stay in {@link String}, the real {@link Class}
@@ -74,7 +74,7 @@ public class InstMethodsInterWithOverrideArgs {
         try {
             interceptor.beforeMethod(targetObject, method, allArguments, method.getParameterTypes(), result);
         } catch (Throwable t) {
-            logger.error(t, "class[{}] before method[{}] intercept failure", obj.getClass(), method.getName());
+            LOGGER.error(t, "class[{}] before method[{}] intercept failure", obj.getClass(), method.getName());
         }
 
         Object ret = null;
@@ -88,14 +88,14 @@ public class InstMethodsInterWithOverrideArgs {
             try {
                 interceptor.handleMethodException(targetObject, method, allArguments, method.getParameterTypes(), t);
             } catch (Throwable t2) {
-                logger.error(t2, "class[{}] handle method[{}] exception failure", obj.getClass(), method.getName());
+                LOGGER.error(t2, "class[{}] handle method[{}] exception failure", obj.getClass(), method.getName());
             }
             throw t;
         } finally {
             try {
                 ret = interceptor.afterMethod(targetObject, method, allArguments, method.getParameterTypes(), ret);
             } catch (Throwable t) {
-                logger.error(t, "class[{}] after method[{}] intercept failure", obj.getClass(), method.getName());
+                LOGGER.error(t, "class[{}] after method[{}] intercept failure", obj.getClass(), method.getName());
             }
         }
         return ret;
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInter.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInter.java
index 3729d80..4d9f00f 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInter.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInter.java
@@ -33,7 +33,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * byte-buddy and sky-walking plugin.
  */
 public class StaticMethodsInter {
-    private static final ILog logger = LogManager.getLogger(StaticMethodsInter.class);
+    private static final ILog LOGGER = LogManager.getLogger(StaticMethodsInter.class);
 
     /**
      * A class full name, and instanceof {@link StaticMethodsAroundInterceptor} This name should only stay in {@link
@@ -72,7 +72,7 @@ public class StaticMethodsInter {
         try {
             interceptor.beforeMethod(clazz, method, allArguments, method.getParameterTypes(), result);
         } catch (Throwable t) {
-            logger.error(t, "class[{}] before static method[{}] intercept failure", clazz, method.getName());
+            LOGGER.error(t, "class[{}] before static method[{}] intercept failure", clazz, method.getName());
         }
 
         Object ret = null;
@@ -86,14 +86,14 @@ public class StaticMethodsInter {
             try {
                 interceptor.handleMethodException(clazz, method, allArguments, method.getParameterTypes(), t);
             } catch (Throwable t2) {
-                logger.error(t2, "class[{}] handle static method[{}] exception failure", clazz, method.getName(), t2.getMessage());
+                LOGGER.error(t2, "class[{}] handle static method[{}] exception failure", clazz, method.getName(), t2.getMessage());
             }
             throw t;
         } finally {
             try {
                 ret = interceptor.afterMethod(clazz, method, allArguments, method.getParameterTypes(), ret);
             } catch (Throwable t) {
-                logger.error(t, "class[{}] after static method[{}] intercept failure:{}", clazz, method.getName(), t.getMessage());
+                LOGGER.error(t, "class[{}] after static method[{}] intercept failure:{}", clazz, method.getName(), t.getMessage());
             }
         }
         return ret;
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInterWithOverrideArgs.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInterWithOverrideArgs.java
index 00ff720..f86e22b 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInterWithOverrideArgs.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/interceptor/enhance/StaticMethodsInterWithOverrideArgs.java
@@ -32,7 +32,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * byte-buddy and sky-walking plugin.
  */
 public class StaticMethodsInterWithOverrideArgs {
-    private static final ILog logger = LogManager.getLogger(StaticMethodsInterWithOverrideArgs.class);
+    private static final ILog LOGGER = LogManager.getLogger(StaticMethodsInterWithOverrideArgs.class);
 
     /**
      * A class full name, and instanceof {@link StaticMethodsAroundInterceptor} This name should only stay in {@link
@@ -71,7 +71,7 @@ public class StaticMethodsInterWithOverrideArgs {
         try {
             interceptor.beforeMethod(clazz, method, allArguments, method.getParameterTypes(), result);
         } catch (Throwable t) {
-            logger.error(t, "class[{}] before static method[{}] intercept failure", clazz, method.getName());
+            LOGGER.error(t, "class[{}] before static method[{}] intercept failure", clazz, method.getName());
         }
 
         Object ret = null;
@@ -85,14 +85,14 @@ public class StaticMethodsInterWithOverrideArgs {
             try {
                 interceptor.handleMethodException(clazz, method, allArguments, method.getParameterTypes(), t);
             } catch (Throwable t2) {
-                logger.error(t2, "class[{}] handle static method[{}] exception failure", clazz, method.getName(), t2.getMessage());
+                LOGGER.error(t2, "class[{}] handle static method[{}] exception failure", clazz, method.getName(), t2.getMessage());
             }
             throw t;
         } finally {
             try {
                 ret = interceptor.afterMethod(clazz, method, allArguments, method.getParameterTypes(), ret);
             } catch (Throwable t) {
-                logger.error(t, "class[{}] after static method[{}] intercept failure:{}", clazz, method.getName(), t.getMessage());
+                LOGGER.error(t, "class[{}] after static method[{}] intercept failure:{}", clazz, method.getName(), t.getMessage());
             }
         }
         return ret;
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/jdk9module/JDK9ModuleExporter.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/jdk9module/JDK9ModuleExporter.java
index 02a46f9..1a5e94f 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/jdk9module/JDK9ModuleExporter.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/jdk9module/JDK9ModuleExporter.java
@@ -30,7 +30,7 @@ import org.apache.skywalking.apm.agent.core.plugin.ByteBuddyCoreClasses;
  * Since JDK 9, module concept has been introduced. By supporting that, agent core needs to open the
  */
 public class JDK9ModuleExporter {
-    private static final ILog logger = LogManager.getLogger(JDK9ModuleExporter.class);
+    private static final ILog LOGGER = LogManager.getLogger(JDK9ModuleExporter.class);
 
     private static final String[] HIGH_PRIORITY_CLASSES = {
         "org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.EnhancedInstance",
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/loader/AgentClassLoader.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/loader/AgentClassLoader.java
index 659712f..a459a22 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/loader/AgentClassLoader.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/loader/AgentClassLoader.java
@@ -52,7 +52,7 @@ public class AgentClassLoader extends ClassLoader {
         registerAsParallelCapable();
     }
 
-    private static final ILog logger = LogManager.getLogger(AgentClassLoader.class);
+    private static final ILog LOGGER = LogManager.getLogger(AgentClassLoader.class);
     /**
      * The default class loader for the agent.
      */
@@ -111,7 +111,7 @@ public class AgentClassLoader extends ClassLoader {
                 }
                 return processLoadedClass(defineClass(name, data, 0, data.length));
             } catch (IOException e) {
-                logger.error(e, "find class fail.");
+                LOGGER.error(e, "find class fail.");
             }
         }
         throw new ClassNotFoundException("Can't find " + name);
@@ -194,9 +194,9 @@ public class AgentClassLoader extends ClassLoader {
                         File file = new File(path, fileName);
                         Jar jar = new Jar(new JarFile(file), file);
                         jars.add(jar);
-                        logger.info("{} loaded.", file.toString());
+                        LOGGER.info("{} loaded.", file.toString());
                     } catch (IOException e) {
-                        logger.error(e, "{} jar file can't be resolved", fileName);
+                        LOGGER.error(e, "{} jar file can't be resolved", fileName);
                     }
                 }
             }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/ProtectiveShieldMatcher.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/ProtectiveShieldMatcher.java
index 7b539c7..5c1020f 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/ProtectiveShieldMatcher.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/match/ProtectiveShieldMatcher.java
@@ -33,7 +33,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * please pay attention to the WARNING logs.
  */
 public class ProtectiveShieldMatcher<T> extends ElementMatcher.Junction.AbstractBase<T> {
-    private static final ILog logger = LogManager.getLogger(ProtectiveShieldMatcher.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProtectiveShieldMatcher.class);
 
     private final ElementMatcher<? super T> matcher;
 
@@ -45,8 +45,8 @@ public class ProtectiveShieldMatcher<T> extends ElementMatcher.Junction.Abstract
         try {
             return this.matcher.matches(target);
         } catch (Throwable t) {
-            if (logger.isDebugEnable()) {
-                logger.debug(t, "Byte-buddy occurs exception when match type.");
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug(t, "Byte-buddy occurs exception when match type.");
             }
             return false;
         }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileSnapshotSender.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileSnapshotSender.java
index 45c1832..499dca1 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileSnapshotSender.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileSnapshotSender.java
@@ -42,7 +42,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Collector.GRPC_UP
  */
 @DefaultImplementor
 public class ProfileSnapshotSender implements BootService, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(ProfileSnapshotSender.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProfileSnapshotSender.class);
 
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
 
@@ -86,8 +86,8 @@ public class ProfileSnapshotSender implements BootService, GRPCChannelListener {
                         public void onError(
                             Throwable throwable) {
                             status.finished();
-                            if (logger.isErrorEnable()) {
-                                logger.error(
+                            if (LOGGER.isErrorEnable()) {
+                                LOGGER.error(
                                     throwable,
                                     "Send profile segment snapshot to collector fail with a grpc internal exception."
                                 );
@@ -109,7 +109,7 @@ public class ProfileSnapshotSender implements BootService, GRPCChannelListener {
                 snapshotStreamObserver.onCompleted();
                 status.wait4Finish();
             } catch (Throwable t) {
-                logger.error(t, "Send profile segment snapshot to backend fail.");
+                LOGGER.error(t, "Send profile segment snapshot to backend fail.");
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskChannelService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskChannelService.java
index 6bcd8f2..56a964c 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskChannelService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskChannelService.java
@@ -55,7 +55,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Collector.GRPC_UP
  */
 @DefaultImplementor
 public class ProfileTaskChannelService implements BootService, Runnable, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(ProfileTaskChannelService.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProfileTaskChannelService.class);
 
     // channel status
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
@@ -93,12 +93,12 @@ public class ProfileTaskChannelService implements BootService, Runnable, GRPCCha
                 ServiceManager.INSTANCE.findService(CommandService.class).receiveCommand(commands);
             } catch (Throwable t) {
                 if (!(t instanceof StatusRuntimeException)) {
-                    logger.error(t, "Query profile task from backend fail.");
+                    LOGGER.error(t, "Query profile task from backend fail.");
                     return;
                 }
                 final StatusRuntimeException statusRuntimeException = (StatusRuntimeException) t;
                 if (statusRuntimeException.getStatus().getCode() == Status.Code.UNIMPLEMENTED) {
-                    logger.warn("Backend doesn't support profiling, profiling will be disabled");
+                    LOGGER.warn("Backend doesn't support profiling, profiling will be disabled");
                     if (getTaskListFuture != null) {
                         getTaskListFuture.cancel(true);
                     }
@@ -128,7 +128,7 @@ public class ProfileTaskChannelService implements BootService, Runnable, GRPCCha
             ).scheduleWithFixedDelay(
                 new RunnableWithExceptionProtection(
                     this,
-                    t -> logger.error("Query profile task list failure.", t)
+                    t -> LOGGER.error("Query profile task list failure.", t)
                 ), 0, Config.Collector.GET_PROFILE_TASK_INTERVAL, TimeUnit.SECONDS
             );
 
@@ -143,7 +143,7 @@ public class ProfileTaskChannelService implements BootService, Runnable, GRPCCha
                             sender.send(buffer);
                         }
                     },
-                    t -> logger.error("Profile segment snapshot upload failure.", t)
+                    t -> LOGGER.error("Profile segment snapshot upload failure.", t)
                 ), 0, 500, TimeUnit.MILLISECONDS
             );
         }
@@ -198,7 +198,7 @@ public class ProfileTaskChannelService implements BootService, Runnable, GRPCCha
             profileTaskBlockingStub.withDeadlineAfter(GRPC_UPSTREAM_TIMEOUT, TimeUnit.SECONDS)
                                    .reportTaskFinish(reportBuilder.build());
         } catch (Throwable e) {
-            logger.error(e, "Notify profile task finish to backend fail.");
+            LOGGER.error(e, "Notify profile task finish to backend fail.");
         }
     }
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskExecutionService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskExecutionService.java
index 44bb5ff..fc7ea2f 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskExecutionService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileTaskExecutionService.java
@@ -43,7 +43,7 @@ import org.apache.skywalking.apm.util.StringUtil;
 @DefaultImplementor
 public class ProfileTaskExecutionService implements BootService, TracingThreadListener {
 
-    private static final ILog logger = LogManager.getLogger(ProfileTaskExecutionService.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProfileTaskExecutionService.class);
 
     // add a schedule while waiting for the task to start or finish
     private final static ScheduledExecutorService PROFILE_TASK_SCHEDULE = Executors.newSingleThreadScheduledExecutor(
@@ -74,7 +74,7 @@ public class ProfileTaskExecutionService implements BootService, TracingThreadLi
         // check profile task limit
         final CheckResult dataError = checkProfileTaskSuccess(task);
         if (!dataError.isSuccess()) {
-            logger.warn(
+            LOGGER.warn(
                 "check command error, cannot process this profile task. reason: {}", dataError.getErrorReason());
             return;
         }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileThread.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileThread.java
index ba0b7ce..fd3a867 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileThread.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/profile/ProfileThread.java
@@ -29,7 +29,7 @@ import java.util.concurrent.atomic.AtomicReferenceArray;
  */
 public class ProfileThread implements Runnable {
 
-    private static final ILog logger = LogManager.getLogger(ProfileThread.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProfileThread.class);
 
     // profiling task context
     private final ProfileTaskExecutionContext taskExecutionContext;
@@ -52,7 +52,7 @@ public class ProfileThread implements Runnable {
             // ignore interrupted
             // means current task has stopped
         } catch (Exception e) {
-            logger.error(e, "Profiling task fail. taskId:{}", taskExecutionContext.getTask().getTaskId());
+            LOGGER.error(e, "Profiling task fail. taskId:{}", taskExecutionContext.getTask().getTaskId());
         } finally {
             // finally stop current profiling task, tell execution service task has stop
             profileTaskExecutionService.stopCurrentProfileTask(taskExecutionContext);
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/AgentIDDecorator.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/AgentIDDecorator.java
index bf71cbf..46ad74d 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/AgentIDDecorator.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/AgentIDDecorator.java
@@ -39,7 +39,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
  * Add agent version(Described in MANIFEST.MF) to the connection establish stage.
  */
 public class AgentIDDecorator implements ChannelDecorator {
-    private static final ILog logger = LogManager.getLogger(AgentIDDecorator.class);
+    private static final ILog LOGGER = LogManager.getLogger(AgentIDDecorator.class);
     private static final Metadata.Key<String> AGENT_VERSION_HEAD_HEADER_NAME = Metadata.Key.of("Agent-Version", Metadata.ASCII_STRING_MARSHALLER);
     private String version = "UNKNOWN";
 
@@ -62,7 +62,7 @@ public class AgentIDDecorator implements ChannelDecorator {
                 }
             }
         } catch (Exception e) {
-            logger.warn("Can't read version from MANIFEST.MF in the agent jar");
+            LOGGER.warn("Can't read version from MANIFEST.MF in the agent jar");
         }
     }
 
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCChannelManager.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCChannelManager.java
index ee98600..ca13a48 100755
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCChannelManager.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCChannelManager.java
@@ -39,7 +39,7 @@ import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
 
 @DefaultImplementor
 public class GRPCChannelManager implements BootService, Runnable {
-    private static final ILog logger = LogManager.getLogger(GRPCChannelManager.class);
+    private static final ILog LOGGER = LogManager.getLogger(GRPCChannelManager.class);
 
     private volatile GRPCChannel managedChannel = null;
     private volatile ScheduledFuture<?> connectCheckFuture;
@@ -58,8 +58,8 @@ public class GRPCChannelManager implements BootService, Runnable {
     @Override
     public void boot() {
         if (Config.Collector.BACKEND_SERVICE.trim().length() == 0) {
-            logger.error("Collector server addresses are not set.");
-            logger.error("Agent will not uplink any data.");
+            LOGGER.error("Collector server addresses are not set.");
+            LOGGER.error("Agent will not uplink any data.");
             return;
         }
         grpcServers = Arrays.asList(Config.Collector.BACKEND_SERVICE.split(","));
@@ -68,7 +68,7 @@ public class GRPCChannelManager implements BootService, Runnable {
         ).scheduleAtFixedRate(
             new RunnableWithExceptionProtection(
                 this,
-                t -> logger.error("unexpected exception.", t)
+                t -> LOGGER.error("unexpected exception.", t)
             ), 0, Config.Collector.GRPC_CHANNEL_CHECK_INTERVAL, TimeUnit.SECONDS
         );
     }
@@ -86,12 +86,12 @@ public class GRPCChannelManager implements BootService, Runnable {
         if (managedChannel != null) {
             managedChannel.shutdownNow();
         }
-        logger.debug("Selected collector grpc service shutdown.");
+        LOGGER.debug("Selected collector grpc service shutdown.");
     }
 
     @Override
     public void run() {
-        logger.debug("Selected collector grpc service running, reconnect:{}.", reconnect);
+        LOGGER.debug("Selected collector grpc service running, reconnect:{}.", reconnect);
         if (reconnect) {
             if (grpcServers.size() > 0) {
                 String server = "";
@@ -127,11 +127,11 @@ public class GRPCChannelManager implements BootService, Runnable {
 
                     return;
                 } catch (Throwable t) {
-                    logger.error(t, "Create channel to {} fail.", server);
+                    LOGGER.error(t, "Create channel to {} fail.", server);
                 }
             }
 
-            logger.debug(
+            LOGGER.debug(
                 "Selected collector grpc service is not available. Wait {} seconds to retry",
                 Config.Collector.GRPC_CHANNEL_CHECK_INTERVAL
             );
@@ -161,7 +161,7 @@ public class GRPCChannelManager implements BootService, Runnable {
             try {
                 listener.statusChanged(status);
             } catch (Throwable t) {
-                logger.error(t, "Fail to notify {} about channel connected.", listener.getClass().getName());
+                LOGGER.error(t, "Fail to notify {} about channel connected.", listener.getClass().getName());
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCStreamServiceStatus.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCStreamServiceStatus.java
index a2c3e0a..da19ac4 100755
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCStreamServiceStatus.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/GRPCStreamServiceStatus.java
@@ -22,7 +22,7 @@ import org.apache.skywalking.apm.agent.core.logging.api.ILog;
 import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
 
 public class GRPCStreamServiceStatus {
-    private static final ILog logger = LogManager.getLogger(GRPCStreamServiceStatus.class);
+    private static final ILog LOGGER = LogManager.getLogger(GRPCStreamServiceStatus.class);
     private volatile boolean status;
 
     public GRPCStreamServiceStatus(boolean status) {
@@ -49,7 +49,7 @@ public class GRPCStreamServiceStatus {
             hasWaited += recheckCycle;
 
             if (recheckCycle >= maxCycle) {
-                logger.warn("Collector traceSegment service doesn't response in {} seconds.", hasWaited / 1000);
+                LOGGER.warn("Collector traceSegment service doesn't response in {} seconds.", hasWaited / 1000);
             } else {
                 recheckCycle = Math.min(recheckCycle * 2, maxCycle);
             }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/ServiceManagementClient.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/ServiceManagementClient.java
index 135a205..e282a63 100755
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/ServiceManagementClient.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/ServiceManagementClient.java
@@ -46,7 +46,7 @@ import static org.apache.skywalking.apm.agent.core.conf.Config.Collector.GRPC_UP
 
 @DefaultImplementor
 public class ServiceManagementClient implements BootService, Runnable, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(ServiceManagementClient.class);
+    private static final ILog LOGGER = LogManager.getLogger(ServiceManagementClient.class);
     private static List<KeyStringValuePair> SERVICE_INSTANCE_PROPERTIES;
 
     private volatile GRPCChannelStatus status = GRPCChannelStatus.DISCONNECT;
@@ -90,7 +90,7 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
         ).scheduleAtFixedRate(
             new RunnableWithExceptionProtection(
                 this,
-                t -> logger.error("unexpected exception.", t)
+                t -> LOGGER.error("unexpected exception.", t)
             ), 0, Config.Collector.HEARTBEAT_PERIOD,
             TimeUnit.SECONDS
         );
@@ -107,7 +107,7 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
 
     @Override
     public void run() {
-        logger.debug("ServiceManagementClient running, status:{}.", status);
+        LOGGER.debug("ServiceManagementClient running, status:{}.", status);
 
         if (GRPCChannelStatus.CONNECTED.equals(status)) {
             try {
@@ -136,7 +136,7 @@ public class ServiceManagementClient implements BootService, Runnable, GRPCChann
                     }
                 }
             } catch (Throwable t) {
-                logger.error(t, "ServiceManagementClient execute fail.");
+                LOGGER.error(t, "ServiceManagementClient execute fail.");
                 ServiceManager.INSTANCE.findService(GRPCChannelManager.class).reportError(t);
             }
         }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/TraceSegmentServiceClient.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/TraceSegmentServiceClient.java
index b1543ac..7ebd366 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/TraceSegmentServiceClient.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/TraceSegmentServiceClient.java
@@ -45,7 +45,7 @@ import static org.apache.skywalking.apm.agent.core.remote.GRPCChannelStatus.CONN
 
 @DefaultImplementor
 public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSegment>, TracingContextListener, GRPCChannelListener {
-    private static final ILog logger = LogManager.getLogger(TraceSegmentServiceClient.class);
+    private static final ILog LOGGER = LogManager.getLogger(TraceSegmentServiceClient.class);
 
     private long lastLogTime;
     private long segmentUplinkedCounter;
@@ -102,8 +102,8 @@ public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSe
                 public void onError(
                     Throwable throwable) {
                     status.finished();
-                    if (logger.isErrorEnable()) {
-                        logger.error(
+                    if (LOGGER.isErrorEnable()) {
+                        LOGGER.error(
                             throwable,
                             "Send UpstreamSegment to collector fail with a grpc internal exception."
                         );
@@ -125,7 +125,7 @@ public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSe
                     upstreamSegmentStreamObserver.onNext(upstreamSegment);
                 }
             } catch (Throwable t) {
-                logger.error(t, "Transform and send UpstreamSegment to collector fail.");
+                LOGGER.error(t, "Transform and send UpstreamSegment to collector fail.");
             }
 
             upstreamSegmentStreamObserver.onCompleted();
@@ -144,11 +144,11 @@ public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSe
         if (currentTimeMillis - lastLogTime > 30 * 1000) {
             lastLogTime = currentTimeMillis;
             if (segmentUplinkedCounter > 0) {
-                logger.debug("{} trace segments have been sent to collector.", segmentUplinkedCounter);
+                LOGGER.debug("{} trace segments have been sent to collector.", segmentUplinkedCounter);
                 segmentUplinkedCounter = 0;
             }
             if (segmentAbandonedCounter > 0) {
-                logger.debug(
+                LOGGER.debug(
                     "{} trace segments have been abandoned, cause by no available channel.", segmentAbandonedCounter);
                 segmentAbandonedCounter = 0;
             }
@@ -157,7 +157,7 @@ public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSe
 
     @Override
     public void onError(List<TraceSegment> data, Throwable t) {
-        logger.error(t, "Try to send {} trace segments to collector, with unexpected exception.", data.size());
+        LOGGER.error(t, "Try to send {} trace segments to collector, with unexpected exception.", data.size());
     }
 
     @Override
@@ -171,8 +171,8 @@ public class TraceSegmentServiceClient implements BootService, IConsumer<TraceSe
             return;
         }
         if (!carrier.produce(traceSegment)) {
-            if (logger.isDebugEnable()) {
-                logger.debug("One trace segment has been abandoned, cause by buffer is full.");
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug("One trace segment has been abandoned, cause by buffer is full.");
             }
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
index c8bf212..d362857 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/sampling/SamplingService.java
@@ -41,7 +41,7 @@ import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
  */
 @DefaultImplementor
 public class SamplingService implements BootService {
-    private static final ILog logger = LogManager.getLogger(SamplingService.class);
+    private static final ILog LOGGER = LogManager.getLogger(SamplingService.class);
 
     private volatile boolean on = false;
     private volatile AtomicInteger samplingFactorHolder;
@@ -67,8 +67,8 @@ public class SamplingService implements BootService {
             ScheduledExecutorService service = Executors.newSingleThreadScheduledExecutor(
                 new DefaultNamedThreadFactory("SamplingService"));
             scheduledFuture = service.scheduleAtFixedRate(new RunnableWithExceptionProtection(
-                this::resetSamplingFactor, t -> logger.error("unexpected exception.", t)), 0, 3, TimeUnit.SECONDS);
-            logger.debug(
+                this::resetSamplingFactor, t -> LOGGER.error("unexpected exception.", t)), 0, 3, TimeUnit.SECONDS);
+            LOGGER.debug(
                 "Agent sampling mechanism started. Sample {} traces in 3 seconds.", Config.Agent.SAMPLE_N_PER_3_SECS);
         }
     }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/util/CustomizeExpression.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/util/CustomizeExpression.java
index 9a301d7..e80d3da 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/util/CustomizeExpression.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/util/CustomizeExpression.java
@@ -34,7 +34,7 @@ import java.util.Map;
 
 public class CustomizeExpression {
 
-    private static final ILog logger = LogManager.getLogger(CustomizeExpression.class);
+    private static final ILog LOGGER = LogManager.getLogger(CustomizeExpression.class);
 
     public static Map<String, Object> evaluationContext(Object[] allArguments) {
         Map<String, Object> context = new HashMap<>();
@@ -70,7 +70,7 @@ public class CustomizeExpression {
                 try {
                     context.put(field.getName(), field.get(ret));
                 } catch (Exception e) {
-                    logger.debug("evaluationReturnContext error, ret is {}, exception is {}", ret, e.getMessage());
+                    LOGGER.debug("evaluationReturnContext error, ret is {}, exception is {}", ret, e.getMessage());
                 }
             }
         }
@@ -83,7 +83,7 @@ public class CustomizeExpression {
             Object o = context.get(es[0]);
             return o == null ? "null" : String.valueOf(parse(es, o, 0));
         } catch (Exception e) {
-            logger.debug("parse expression error, expression is {}, exception is {}", expression, e.getMessage());
+            LOGGER.debug("parse expression error, expression is {}, exception is {}", expression, e.getMessage());
         }
         return "null";
     }
@@ -97,7 +97,7 @@ public class CustomizeExpression {
             Object o = context.get(es[1]);
             return o == null ? "null" : String.valueOf(parse(es, o, 1));
         } catch (Exception e) {
-            logger.debug("parse expression error, expression is {}, exception is {}", expression, e.getMessage());
+            LOGGER.debug("parse expression error, expression is {}, exception is {}", expression, e.getMessage());
         }
         return "null";
     }
@@ -152,7 +152,7 @@ public class CustomizeExpression {
                 return f.get(o);
             }
         } catch (Exception e) {
-            logger.debug("matcher default error, expression is {}, object is {}, expression is {}", expression, o, e.getMessage());
+            LOGGER.debug("matcher default error, expression is {}, object is {}, expression is {}", expression, o, e.getMessage());
         }
         return null;
     }
diff --git a/apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java b/apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java
index 1508a2e..7167d29 100644
--- a/apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java
+++ b/apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java
@@ -53,7 +53,7 @@ import static net.bytebuddy.matcher.ElementMatchers.not;
  * The main entrance of sky-walking agent, based on javaagent mechanism.
  */
 public class SkyWalkingAgent {
-    private static final ILog logger = LogManager.getLogger(SkyWalkingAgent.class);
+    private static final ILog LOGGER = LogManager.getLogger(SkyWalkingAgent.class);
 
     /**
      * Main entrance. Use byte-buddy transform to enhance all classes, which define in plugins.
@@ -65,10 +65,10 @@ public class SkyWalkingAgent {
 
             pluginFinder = new PluginFinder(new PluginBootstrap().loadPlugins());
         } catch (AgentPackageNotFoundException ape) {
-            logger.error(ape, "Locate agent.jar failure. Shutting down.");
+            LOGGER.error(ape, "Locate agent.jar failure. Shutting down.");
             return;
         } catch (Exception e) {
-            logger.error(e, "SkyWalking agent initialized failure. Shutting down.");
+            LOGGER.error(e, "SkyWalking agent initialized failure. Shutting down.");
             return;
         }
 
@@ -88,23 +88,23 @@ public class SkyWalkingAgent {
         try {
             agentBuilder = BootstrapInstrumentBoost.inject(pluginFinder, instrumentation, agentBuilder, edgeClasses);
         } catch (Exception e) {
-            logger.error(e, "SkyWalking agent inject bootstrap instrumentation failure. Shutting down.");
+            LOGGER.error(e, "SkyWalking agent inject bootstrap instrumentation failure. Shutting down.");
             return;
         }
 
         try {
             agentBuilder = JDK9ModuleExporter.openReadEdge(instrumentation, agentBuilder, edgeClasses);
         } catch (Exception e) {
-            logger.error(e, "SkyWalking agent open read edge in JDK 9+ failure. Shutting down.");
+            LOGGER.error(e, "SkyWalking agent open read edge in JDK 9+ failure. Shutting down.");
             return;
         }
 
         if (Config.Agent.IS_CACHE_ENHANCED_CLASS) {
             try {
                 agentBuilder = agentBuilder.with(new CacheableTransformerDecorator(Config.Agent.CLASS_CACHE_MODE));
-                logger.info("SkyWalking agent class cache [{}] activated.", Config.Agent.CLASS_CACHE_MODE);
+                LOGGER.info("SkyWalking agent class cache [{}] activated.", Config.Agent.CLASS_CACHE_MODE);
             } catch (Exception e) {
-                logger.error(e, "SkyWalking agent can't active class cache.");
+                LOGGER.error(e, "SkyWalking agent can't active class cache.");
             }
         }
 
@@ -117,7 +117,7 @@ public class SkyWalkingAgent {
         try {
             ServiceManager.INSTANCE.boot();
         } catch (Exception e) {
-            logger.error(e, "Skywalking agent boot failure.");
+            LOGGER.error(e, "Skywalking agent boot failure.");
         }
 
         Runtime.getRuntime()
@@ -148,13 +148,13 @@ public class SkyWalkingAgent {
                     }
                 }
                 if (context.isEnhanced()) {
-                    logger.debug("Finish the prepare stage for {}.", typeDescription.getName());
+                    LOGGER.debug("Finish the prepare stage for {}.", typeDescription.getName());
                 }
 
                 return newBuilder;
             }
 
-            logger.debug("Matched class {}, but ignore by finding mechanism.", typeDescription.getTypeName());
+            LOGGER.debug("Matched class {}, but ignore by finding mechanism.", typeDescription.getTypeName());
             return builder;
         }
     }
@@ -175,8 +175,8 @@ public class SkyWalkingAgent {
                                      final JavaModule module,
                                      final boolean loaded,
                                      final DynamicType dynamicType) {
-            if (logger.isDebugEnable()) {
-                logger.debug("On Transformation class {}.", typeDescription.getName());
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug("On Transformation class {}.", typeDescription.getName());
             }
 
             InstrumentDebuggingClass.INSTANCE.log(dynamicType);
@@ -196,7 +196,7 @@ public class SkyWalkingAgent {
                             final JavaModule module,
                             final boolean loaded,
                             final Throwable throwable) {
-            logger.error("Enhance class " + typeName + " error.", throwable);
+            LOGGER.error("Enhance class " + typeName + " error.", throwable);
         }
 
         @Override
diff --git a/apm-sniffer/apm-sdk-plugin/avro-plugin/src/main/java/org/apache/skywalking/apm/plugin/avro/AbstractRequestInterceptor.java b/apm-sniffer/apm-sdk-plugin/avro-plugin/src/main/java/org/apache/skywalking/apm/plugin/avro/AbstractRequestInterceptor.java
index 347d7a1..59f2036 100644
--- a/apm-sniffer/apm-sdk-plugin/avro-plugin/src/main/java/org/apache/skywalking/apm/plugin/avro/AbstractRequestInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/avro-plugin/src/main/java/org/apache/skywalking/apm/plugin/avro/AbstractRequestInterceptor.java
@@ -31,7 +31,7 @@ import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceC
 import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 
 public abstract class AbstractRequestInterceptor implements InstanceConstructorInterceptor, InstanceMethodsAroundInterceptor {
-    private static final ILog logger = LogManager.getLogger(GenericRequestorInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(GenericRequestorInterceptor.class);
 
     @Override
     public void onConstruct(EnhancedInstance objInst, Object[] allArguments) {
@@ -46,7 +46,7 @@ public abstract class AbstractRequestInterceptor implements InstanceConstructorI
                     .getRemoteName()));
             } catch (IOException e) {
                 objInst.setSkyWalkingDynamicField(new AvroInstance("Undefined", "Undefined"));
-                logger.error("Failed to get Avro Remote Client Information.", e);
+                LOGGER.error("Failed to get Avro Remote Client Information.", e);
             }
         }
     }
diff --git a/apm-sniffer/apm-sdk-plugin/elasticsearch-5.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v5/TransportProxyClientInterceptor.java b/apm-sniffer/apm-sdk-plugin/elasticsearch-5.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v5/TransportProxyClientInterceptor.java
index 1d8343a..20974d6 100644
--- a/apm-sniffer/apm-sdk-plugin/elasticsearch-5.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v5/TransportProxyClientInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/elasticsearch-5.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v5/TransportProxyClientInterceptor.java
@@ -37,7 +37,7 @@ import static org.apache.skywalking.apm.plugin.elasticsearch.v5.ElasticsearchPlu
 
 public class TransportProxyClientInterceptor implements InstanceConstructorInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(TransportProxyClientInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(TransportProxyClientInterceptor.class);
 
     @Override
     public void onConstruct(EnhancedInstance objInst, Object[] allArguments) {
@@ -121,7 +121,7 @@ public class TransportProxyClientInterceptor implements InstanceConstructorInter
             try {
                 updateDsl = updateRequest.toXContent(XContentFactory.jsonBuilder(), null).string();
             } catch (IOException e) {
-                logger.warn("trace update request dsl error: ", e);
+                LOGGER.warn("trace update request dsl error: ", e);
             }
             enhanceInfo.setSource(updateDsl);
         }
diff --git a/apm-sniffer/apm-sdk-plugin/elasticsearch-6.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v6/interceptor/RestHighLevelClientConInterceptor.java b/apm-sniffer/apm-sdk-plugin/elasticsearch-6.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v6/interceptor/RestHighLevelClientConInterceptor.java
index 727e105..ae3982c 100644
--- a/apm-sniffer/apm-sdk-plugin/elasticsearch-6.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v6/interceptor/RestHighLevelClientConInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/elasticsearch-6.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/elasticsearch/v6/interceptor/RestHighLevelClientConInterceptor.java
@@ -30,7 +30,7 @@ import org.elasticsearch.client.RestClientBuilder;
 
 public class RestHighLevelClientConInterceptor implements InstanceConstructorInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(RestHighLevelClientConInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(RestHighLevelClientConInterceptor.class);
 
     @Override
     public void onConstruct(EnhancedInstance objInst, Object[] allArguments) {
diff --git a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v30/MongoDBInterceptor.java b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v30/MongoDBInterceptor.java
index afeac7b..7ac199a 100644
--- a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v30/MongoDBInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v30/MongoDBInterceptor.java
@@ -44,7 +44,7 @@ import java.lang.reflect.Method;
 })
 public class MongoDBInterceptor implements InstanceMethodsAroundInterceptor, InstanceConstructorInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(MongoDBInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(MongoDBInterceptor.class);
 
     @Override
     public void onConstruct(EnhancedInstance objInst, Object[] allArguments) {
@@ -58,8 +58,8 @@ public class MongoDBInterceptor implements InstanceMethodsAroundInterceptor, Ins
         MethodInterceptResult result) {
         String executeMethod = allArguments[0].getClass().getSimpleName();
         String remotePeer = (String) objInst.getSkyWalkingDynamicField();
-        if (logger.isDebugEnable()) {
-            logger.debug("Mongo execute: [executeMethod: {}, remotePeer: {}]", executeMethod, remotePeer);
+        if (LOGGER.isDebugEnable()) {
+            LOGGER.debug("Mongo execute: [executeMethod: {}, remotePeer: {}]", executeMethod, remotePeer);
         }
         MongoSpanHelper.createExitSpan(executeMethod, remotePeer, allArguments[0]);
     }
diff --git a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBClientDelegateInterceptor.java b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBClientDelegateInterceptor.java
index cfc901e..9a70f1f 100644
--- a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBClientDelegateInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBClientDelegateInterceptor.java
@@ -32,7 +32,7 @@ import java.lang.reflect.Method;
 @SuppressWarnings("Duplicates")
 public class MongoDBClientDelegateInterceptor implements InstanceConstructorInterceptor, InstanceMethodsAroundInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(MongoDBClientDelegateInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(MongoDBClientDelegateInterceptor.class);
 
     @SuppressWarnings("deprecation")
     @Override
@@ -56,8 +56,8 @@ public class MongoDBClientDelegateInterceptor implements InstanceConstructorInte
             // @see: org.apache.skywalking.apm.plugin.mongodb.v3.define.v37.MongoDBOperationExecutorInstrumentation
             EnhancedInstance retInstance = (EnhancedInstance) ret;
             String remotePeer = (String) objInst.getSkyWalkingDynamicField();
-            if (logger.isDebugEnable()) {
-                logger.debug("Mark OperationExecutor remotePeer: {}", remotePeer);
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug("Mark OperationExecutor remotePeer: {}", remotePeer);
             }
             retInstance.setSkyWalkingDynamicField(remotePeer);
         }
diff --git a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBOperationExecutorInterceptor.java b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBOperationExecutorInterceptor.java
index cf3e402..fb4da5d 100644
--- a/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBOperationExecutorInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/mongodb/v3/interceptor/v37/MongoDBOperationExecutorInterceptor.java
@@ -32,7 +32,7 @@ import java.lang.reflect.Method;
 @SuppressWarnings("Duplicates")
 public class MongoDBOperationExecutorInterceptor implements InstanceMethodsAroundInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(MongoDBOperationExecutorInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(MongoDBOperationExecutorInterceptor.class);
 
     @Override
     public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
@@ -41,8 +41,8 @@ public class MongoDBOperationExecutorInterceptor implements InstanceMethodsAroun
         // OperationExecutor has be mark it's remotePeer
         // @see: MongoDBClientDelegateInterceptor.afterMethod
         String remotePeer = (String) objInst.getSkyWalkingDynamicField();
-        if (logger.isDebugEnable()) {
-            logger.debug("Mongo execute: [executeMethod: {}, remotePeer: {}]", executeMethod, remotePeer);
+        if (LOGGER.isDebugEnable()) {
+            LOGGER.debug("Mongo execute: [executeMethod: {}, remotePeer: {}]", executeMethod, remotePeer);
         }
         MongoSpanHelper.createExitSpan(executeMethod, remotePeer, allArguments[0]);
     }
diff --git a/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/ConnectionManagerInterceptor.java b/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/ConnectionManagerInterceptor.java
index 291f21b..d4b352d 100644
--- a/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/ConnectionManagerInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/ConnectionManagerInterceptor.java
@@ -34,7 +34,7 @@ import java.util.Collection;
 
 public class ConnectionManagerInterceptor implements InstanceMethodsAroundInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(ConnectionManagerInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(ConnectionManagerInterceptor.class);
 
     @Override
     public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
@@ -86,7 +86,7 @@ public class ConnectionManagerInterceptor implements InstanceMethodsAroundInterc
                 return ret;
             }
         } catch (Exception e) {
-            logger.warn("redisClient set peer error: ", e);
+            LOGGER.warn("redisClient set peer error: ", e);
         }
         return ret;
     }
@@ -113,7 +113,7 @@ public class ConnectionManagerInterceptor implements InstanceMethodsAroundInterc
             URI uri = (URI) obj;
             return uri.getHost() + ":" + uri.getPort();
         } else {
-            logger.warn("redisson not support this version");
+            LOGGER.warn("redisson not support this version");
             return null;
         }
     }
diff --git a/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/RedisConnectionMethodInterceptor.java b/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/RedisConnectionMethodInterceptor.java
index bcf8d75..f87b7bf 100644
--- a/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/RedisConnectionMethodInterceptor.java
+++ b/apm-sniffer/apm-sdk-plugin/redisson-3.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/redisson/v3/RedisConnectionMethodInterceptor.java
@@ -42,7 +42,7 @@ import java.net.InetSocketAddress;
 
 public class RedisConnectionMethodInterceptor implements InstanceMethodsAroundInterceptor, InstanceConstructorInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(RedisConnectionMethodInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(RedisConnectionMethodInterceptor.class);
 
     @Override
     public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
@@ -118,7 +118,7 @@ public class RedisConnectionMethodInterceptor implements InstanceMethodsAroundIn
                 String port = String.valueOf(ClassUtil.getObjectField(address, "port"));
                 peer = host + ":" + port;
             } catch (Exception e) {
-                logger.warn("RedisConnection create peer error: ", e);
+                LOGGER.warn("RedisConnection create peer error: ", e);
             }
         }
         objInst.setSkyWalkingDynamicField(peer);
diff --git a/apm-sniffer/apm-toolkit-activation/apm-toolkit-trace-activation/src/main/java/org/apache/skywalking/apm/toolkit/activation/trace/TraceContextInterceptor.java b/apm-sniffer/apm-toolkit-activation/apm-toolkit-trace-activation/src/main/java/org/apache/skywalking/apm/toolkit/activation/trace/TraceContextInterceptor.java
index ae271bc..debc686 100644
--- a/apm-sniffer/apm-toolkit-activation/apm-toolkit-trace-activation/src/main/java/org/apache/skywalking/apm/toolkit/activation/trace/TraceContextInterceptor.java
+++ b/apm-sniffer/apm-toolkit-activation/apm-toolkit-trace-activation/src/main/java/org/apache/skywalking/apm/toolkit/activation/trace/TraceContextInterceptor.java
@@ -27,7 +27,7 @@ import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInt
 
 public class TraceContextInterceptor implements StaticMethodsAroundInterceptor {
 
-    private ILog logger = LogManager.getLogger(TraceContextInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(TraceContextInterceptor.class);
 
     @Override
     public void beforeMethod(Class clazz, Method method, Object[] allArguments, Class<?>[] parameterTypes,
@@ -44,6 +44,6 @@ public class TraceContextInterceptor implements StaticMethodsAroundInterceptor {
     @Override
     public void handleMethodException(Class clazz, Method method, Object[] allArguments, Class<?>[] parameterTypes,
         Throwable t) {
-        logger.error("Failed to getDefault trace Id.", t);
+        LOGGER.error("Failed to getDefault trace Id.", t);
     }
 }
diff --git a/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/conf/CustomizeConfiguration.java b/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/conf/CustomizeConfiguration.java
index 6c79144..2c1864b 100644
--- a/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/conf/CustomizeConfiguration.java
+++ b/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/conf/CustomizeConfiguration.java
@@ -57,7 +57,7 @@ public enum CustomizeConfiguration {
 
     INSTANCE;
 
-    private static final ILog logger = LogManager.getLogger(CustomizeConfiguration.class);
+    private static final ILog LOGGER = LogManager.getLogger(CustomizeConfiguration.class);
 
     /**
      * Some information after custom enhancements, this configuration is used by the custom enhancement plugin.
@@ -76,7 +76,7 @@ public enum CustomizeConfiguration {
                 addContextEnhanceClass(configuration);
             }
         } catch (Exception e) {
-            logger.error("CustomizeConfiguration loadForAgent fail", e);
+            LOGGER.error("CustomizeConfiguration loadForAgent fail", e);
         }
     }
 
@@ -92,7 +92,7 @@ public enum CustomizeConfiguration {
                 addContextMethodConfiguration(configuration);
             }
         } catch (Exception e) {
-            logger.error("CustomizeConfiguration loadForConfiguration fail", e);
+            LOGGER.error("CustomizeConfiguration loadForConfiguration fail", e);
         } finally {
             LOAD_FOR_CONFIGURATION.set(true);
         }
@@ -257,7 +257,7 @@ public enum CustomizeConfiguration {
             }
             return configuration;
         } catch (Exception e) {
-            logger.error(e, "Failed to resolver, className is {}, methodDesc is {}.", className, methodDesc);
+            LOGGER.error(e, "Failed to resolver, className is {}, methodDesc is {}.", className, methodDesc);
         }
         return null;
     }
diff --git a/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/loader/CustomizeInstrumentationLoader.java b/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/loader/CustomizeInstrumentationLoader.java
index d044f41..3c52c86 100644
--- a/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/loader/CustomizeInstrumentationLoader.java
+++ b/apm-sniffer/optional-plugins/customize-enhance-plugin/src/main/java/org/apache/skywalking/apm/plugin/customize/loader/CustomizeInstrumentationLoader.java
@@ -38,7 +38,7 @@ import java.util.Set;
 
 public class CustomizeInstrumentationLoader implements InstrumentationLoader {
 
-    private static final ILog logger = LogManager.getLogger(CustomizeInstrumentationLoader.class);
+    private static final ILog LOGGER = LogManager.getLogger(CustomizeInstrumentationLoader.class);
 
     @Override
     public List<AbstractClassEnhancePluginDefine> load(AgentClassLoader classLoader) {
@@ -55,7 +55,7 @@ public class CustomizeInstrumentationLoader implements InstrumentationLoader {
                 instrumentations.add(plugin);
             }
         } catch (Exception e) {
-            logger.error(e, "InstrumentationLoader loader is error, spi loader is {}", CustomizeInstrumentationLoader.class
+            LOGGER.error(e, "InstrumentationLoader loader is error, spi loader is {}", CustomizeInstrumentationLoader.class
                 .getName());
         }
         return instrumentations;
diff --git a/apm-sniffer/optional-plugins/zookeeper-3.4.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/zookeeper/ClientCnxnInterceptor.java b/apm-sniffer/optional-plugins/zookeeper-3.4.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/zookeeper/ClientCnxnInterceptor.java
index 4334d95..0da36cf 100644
--- a/apm-sniffer/optional-plugins/zookeeper-3.4.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/zookeeper/ClientCnxnInterceptor.java
+++ b/apm-sniffer/optional-plugins/zookeeper-3.4.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/zookeeper/ClientCnxnInterceptor.java
@@ -42,7 +42,7 @@ import java.util.List;
 
 public class ClientCnxnInterceptor implements InstanceMethodsAroundInterceptor, InstanceConstructorInterceptor {
 
-    private static final ILog logger = LogManager.getLogger(ClientCnxnInterceptor.class);
+    private static final ILog LOGGER = LogManager.getLogger(ClientCnxnInterceptor.class);
 
     @Override
     public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes,
@@ -90,9 +90,9 @@ public class ClientCnxnInterceptor implements InstanceMethodsAroundInterceptor,
             }
             objInst.setSkyWalkingDynamicField(peer.toString());
         } catch (NoSuchFieldException e) {
-            logger.warn("NoSuchFieldException, not be compatible with this version of zookeeper", e);
+            LOGGER.warn("NoSuchFieldException, not be compatible with this version of zookeeper", e);
         } catch (IllegalAccessException e) {
-            logger.warn("IllegalAccessException, not be compatible with this version of zookeeper", e);
+            LOGGER.warn("IllegalAccessException, not be compatible with this version of zookeeper", e);
         }
     }
 }
diff --git a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaJVMMetricsSender.java b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaJVMMetricsSender.java
index f09af4a..6a399eb 100644
--- a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaJVMMetricsSender.java
+++ b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaJVMMetricsSender.java
@@ -39,7 +39,7 @@ import org.apache.skywalking.apm.network.language.agent.v3.JVMMetricCollection;
  */
 @OverrideImplementor(JVMMetricsSender.class)
 public class KafkaJVMMetricsSender extends JVMMetricsSender {
-    private static final ILog logger = LogManager.getLogger(KafkaJVMMetricsSender.class);
+    private static final ILog LOGGER = LogManager.getLogger(KafkaJVMMetricsSender.class);
     private KafkaProducer<String, Bytes> producer;
     private String topic;
 
@@ -59,8 +59,8 @@ public class KafkaJVMMetricsSender extends JVMMetricsSender {
                                                                  .setServiceInstance(Config.Agent.INSTANCE_NAME)
                                                                  .build();
 
-                if (logger.isDebugEnable()) {
-                    logger.debug(
+                if (LOGGER.isDebugEnable()) {
+                    LOGGER.debug(
                         "JVM metrics reporting, topic: {}, key: {}, length: {}", topic, metrics.getServiceInstance(),
                         buffer.size()
                     );
diff --git a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaMeterSender.java b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaMeterSender.java
index df1eb51..f20d9c4 100644
--- a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaMeterSender.java
+++ b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaMeterSender.java
@@ -38,7 +38,7 @@ import org.apache.skywalking.apm.network.language.agent.v3.MeterDataCollection;
  */
 @OverrideImplementor(MeterSender.class)
 public class KafkaMeterSender extends MeterSender {
-    private static final ILog logger = LogManager.getLogger(KafkaTraceSegmentServiceClient.class);
+    private static final ILog LOGGER = LogManager.getLogger(KafkaTraceSegmentServiceClient.class);
 
     private String topic;
     private KafkaProducer<String, Bytes> producer;
@@ -56,8 +56,8 @@ public class KafkaMeterSender extends MeterSender {
     public void send(Map<MeterId, MeterTransformer> meterMap, MeterService meterService) {
         MeterDataCollection.Builder builder = MeterDataCollection.newBuilder();
         transform(meterMap, meterData -> {
-            if (logger.isDebugEnable()) {
-                logger.debug("Meter data reporting, instance: {}", meterData.getServiceInstance());
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug("Meter data reporting, instance: {}", meterData.getServiceInstance());
             }
             builder.addMeterData(meterData);
         });
diff --git a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaProfileSnapshotSender.java b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaProfileSnapshotSender.java
index 13170d0..14ff6ff 100644
--- a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaProfileSnapshotSender.java
+++ b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaProfileSnapshotSender.java
@@ -36,7 +36,7 @@ import org.apache.skywalking.apm.network.language.profile.v3.ThreadSnapshot;
  */
 @OverrideImplementor(ProfileSnapshotSender.class)
 public class KafkaProfileSnapshotSender extends ProfileSnapshotSender {
-    private static final ILog logger = LogManager.getLogger(ProfileSnapshotSender.class);
+    private static final ILog LOGGER = LogManager.getLogger(ProfileSnapshotSender.class);
 
     private String topic;
     private KafkaProducer<String, Bytes> producer;
@@ -55,8 +55,8 @@ public class KafkaProfileSnapshotSender extends ProfileSnapshotSender {
     public void send(final List<TracingThreadSnapshot> buffer) {
         for (TracingThreadSnapshot snapshot : buffer) {
             final ThreadSnapshot object = snapshot.transform();
-            if (logger.isDebugEnable()) {
-                logger.debug("Thread snapshot reporting, topic: {}, taskId: {}, sequence:{}, traceId: {}",
+            if (LOGGER.isDebugEnable()) {
+                LOGGER.debug("Thread snapshot reporting, topic: {}, taskId: {}, sequence:{}, traceId: {}",
                              object.getTaskId(), object.getSequence(), object.getTraceSegmentId()
                 );
             }
diff --git a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaServiceManagementServiceClient.java b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaServiceManagementServiceClient.java
index 2b99d50..d07766a 100644
--- a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaServiceManagementServiceClient.java
+++ b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaServiceManagementServiceClient.java
@@ -47,7 +47,7 @@ import org.apache.skywalking.apm.util.StringUtil;
  */
 @OverrideImplementor(ServiceManagementClient.class)
 public class KafkaServiceManagementServiceClient implements BootService, Runnable {
-    private static final ILog logger = LogManager.getLogger(KafkaServiceManagementServiceClient.class);
+    private static final ILog LOGGER = LogManager.getLogger(KafkaServiceManagementServiceClient.class);
 
     private static List<KeyStringValuePair> SERVICE_INSTANCE_PROPERTIES;
 
@@ -83,7 +83,7 @@ public class KafkaServiceManagementServiceClient implements BootService, Runnabl
             new DefaultNamedThreadFactory("ServiceManagementClientKafkaProducer")
         ).scheduleAtFixedRate(new RunnableWithExceptionProtection(
             this,
-            t -> logger.error("unexpected exception.", t)
+            t -> LOGGER.error("unexpected exception.", t)
         ), 0, Config.Collector.HEARTBEAT_PERIOD, TimeUnit.SECONDS);
 
         InstanceProperties instance = InstanceProperties.newBuilder()
@@ -103,8 +103,8 @@ public class KafkaServiceManagementServiceClient implements BootService, Runnabl
                                               .setService(Config.Agent.SERVICE_NAME)
                                               .setServiceInstance(Config.Agent.INSTANCE_NAME)
                                               .build();
-        if (logger.isDebugEnable()) {
-            logger.debug("Heartbeat reporting, instance: {}", ping.getServiceInstance());
+        if (LOGGER.isDebugEnable()) {
+            LOGGER.debug("Heartbeat reporting, instance: {}", ping.getServiceInstance());
         }
         producer.send(new ProducerRecord<>(topic, ping.getServiceInstance(), Bytes.wrap(ping.toByteArray())));
     }
diff --git a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaTraceSegmentServiceClient.java b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaTraceSegmentServiceClient.java
index 322f7c3..6672048 100644
--- a/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaTraceSegmentServiceClient.java
+++ b/apm-sniffer/optional-reporter-plugins/kafka-reporter-plugin/src/main/java/org/apache/skywalking/apm/agent/core/kafka/KafkaTraceSegmentServiceClient.java
@@ -37,7 +37,7 @@ import org.apache.skywalking.apm.network.language.agent.v3.SegmentObject;
  */
 @OverrideImplementor(TraceSegmentServiceClient.class)
 public class KafkaTraceSegmentServiceClient implements BootService, TracingContextListener {
-    private static final ILog logger = LogManager.getLogger(KafkaTraceSegmentServiceClient.class);
+    private static final ILog LOGGER = LogManager.getLogger(KafkaTraceSegmentServiceClient.class);
 
     private String topic;
     private KafkaProducer<String, Bytes> producer;
@@ -64,12 +64,12 @@ public class KafkaTraceSegmentServiceClient implements BootService, TracingConte
 
     @Override
     public void afterFinished(final TraceSegment traceSegment) {
-        if (logger.isDebugEnable()) {
-            logger.debug("Trace segment reporting, traceId: {}", traceSegment.getTraceSegmentId());
+        if (LOGGER.isDebugEnable()) {
+            LOGGER.debug("Trace segment reporting, traceId: {}", traceSegment.getTraceSegmentId());
         }
 
         if (traceSegment.isIgnore()) {
-            logger.debug("Trace[TraceId={}] is ignored.", traceSegment.getTraceSegmentId());
+            LOGGER.debug("Trace[TraceId={}] is ignored.", traceSegment.getTraceSegmentId());
             return;
         }
         SegmentObject upstreamSegment = traceSegment.transform();
diff --git a/oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/jvm/JVMSourceDispatcher.java b/oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/jvm/JVMSourceDispatcher.java
index 97f0ab4..d1211f8 100644
--- a/oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/jvm/JVMSourceDispatcher.java
+++ b/oap-server/analyzer/agent-analyzer/src/main/java/org/apache/skywalking/oap/server/analyzer/provider/jvm/JVMSourceDispatcher.java
@@ -42,7 +42,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class JVMSourceDispatcher {
-    private static final Logger logger = LoggerFactory.getLogger(JVMSourceDispatcher.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JVMSourceDispatcher.class);
     private final SourceReceiver sourceReceiver;
 
     public JVMSourceDispatcher(ModuleManager moduleManager) {
diff --git a/oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporter.java b/oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporter.java
index 963004c..e14b38e 100644
--- a/oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporter.java
+++ b/oap-server/exporter/src/main/java/org/apache/skywalking/oap/server/exporter/provider/grpc/GRPCExporter.java
@@ -50,7 +50,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class GRPCExporter extends MetricFormatter implements MetricValuesExportService, IConsumer<ExportData> {
-    private static final Logger logger = LoggerFactory.getLogger(GRPCExporter.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GRPCExporter.class);
 
     private GRPCExporterSetting setting;
     private final MetricExportServiceGrpc.MetricExportServiceStub exportServiceFutureStub;
@@ -87,7 +87,7 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
         SubscriptionsResp subscription = blockingStub.withDeadlineAfter(10, TimeUnit.SECONDS)
                                                      .subscription(SubscriptionReq.newBuilder().build());
         subscription.getMetricNamesList().forEach(subscriptionSet::add);
-        logger.debug("Get exporter subscription list, {}", subscriptionSet);
+        LOGGER.debug("Get exporter subscription list, {}", subscriptionSet);
     }
 
     @Override
@@ -179,7 +179,7 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
             }
 
             if (sleepTime > 2000L) {
-                logger.warn(
+                LOGGER.warn(
                     "Export {} metrics to {}:{}, wait {} milliseconds.", exportNum.get(), setting.getTargetHost(),
                     setting
                         .getTargetPort(), sleepTime
@@ -188,14 +188,14 @@ public class GRPCExporter extends MetricFormatter implements MetricValuesExportS
             }
         }
 
-        logger.debug(
+        LOGGER.debug(
             "Exported {} metrics to {}:{} in {} milliseconds.", exportNum.get(), setting.getTargetHost(), setting
                 .getTargetPort(), sleepTime);
     }
 
     @Override
     public void onError(List<ExportData> data, Throwable t) {
-        logger.error(t.getMessage(), t);
+        LOGGER.error(t.getMessage(), t);
     }
 
     @Override
diff --git a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java
index 019b031..03afbf6 100644
--- a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java
+++ b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/AlarmCore.java
@@ -34,7 +34,7 @@ import org.slf4j.LoggerFactory;
  * trigger and the alarm rules to decides whether send the alarm to database and webhook(s)
  */
 public class AlarmCore {
-    private static final Logger logger = LoggerFactory.getLogger(AlarmCore.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(AlarmCore.class);
 
     private LocalDateTime lastExecuteTime;
     private AlarmRulesWatcher alarmRulesWatcher;
@@ -77,7 +77,7 @@ public class AlarmCore {
                     allCallbacks.forEach(callback -> callback.doAlarm(alarmMessageList));
                 }
             } catch (Exception e) {
-                logger.error(e.getMessage(), e);
+                LOGGER.error(e.getMessage(), e);
             }
         }, 10, 10, TimeUnit.SECONDS);
     }
diff --git a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/Threshold.java b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/Threshold.java
index 61eef4e..ba3299c 100644
--- a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/Threshold.java
+++ b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/Threshold.java
@@ -22,7 +22,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class Threshold {
-    private static final Logger logger = LoggerFactory.getLogger(Threshold.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(Threshold.class);
     private static final String NONE_THRESHOLD = "-";
 
     private String alarmRuleName;
@@ -78,7 +78,7 @@ public class Threshold {
                     }
             }
         } catch (NumberFormatException e) {
-            logger.warn("Alarm rule {} threshold doesn't match the metrics type, expected type: {}", alarmRuleName, type);
+            LOGGER.warn("Alarm rule {} threshold doesn't match the metrics type, expected type: {}", alarmRuleName, type);
         }
     }
 }
diff --git a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/WebhookCallback.java b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/WebhookCallback.java
index f0fe041..a9d5333 100644
--- a/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/WebhookCallback.java
+++ b/oap-server/server-alarm-plugin/src/main/java/org/apache/skywalking/oap/server/core/alarm/provider/WebhookCallback.java
@@ -42,7 +42,7 @@ import org.slf4j.LoggerFactory;
  * Use SkyWalking alarm webhook API call a remote endpoints.
  */
 public class WebhookCallback implements AlarmCallback {
-    private static final Logger logger = LoggerFactory.getLogger(WebhookCallback.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(WebhookCallback.class);
     private static final int HTTP_CONNECT_TIMEOUT = 1000;
     private static final int HTTP_CONNECTION_REQUEST_TIMEOUT = 1000;
     private static final int HTTP_SOCKET_TIMEOUT = 10000;
@@ -81,19 +81,19 @@ public class WebhookCallback implements AlarmCallback {
                     CloseableHttpResponse httpResponse = httpClient.execute(post);
                     StatusLine statusLine = httpResponse.getStatusLine();
                     if (statusLine != null && statusLine.getStatusCode() != HttpStatus.SC_OK) {
-                        logger.error("send alarm to " + url + " failure. Response code: " + statusLine.getStatusCode());
+                        LOGGER.error("send alarm to " + url + " failure. Response code: " + statusLine.getStatusCode());
                     }
                 } catch (UnsupportedEncodingException e) {
-                    logger.error("Alarm to JSON error, " + e.getMessage(), e);
+                    LOGGER.error("Alarm to JSON error, " + e.getMessage(), e);
                 } catch (IOException e) {
-                    logger.error("send alarm to " + url + " failure.", e);
+                    LOGGER.error("send alarm to " + url + " failure.", e);
                 }
             });
         } finally {
             try {
                 httpClient.close();
             } catch (IOException e) {
-                logger.error(e.getMessage(), e);
+                LOGGER.error(e.getMessage(), e);
             }
         }
     }
diff --git a/oap-server/server-cluster-plugin/cluster-etcd-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/etcd/EtcdCoordinator.java b/oap-server/server-cluster-plugin/cluster-etcd-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/etcd/EtcdCoordinator.java
index 706cc6d..0b3fb9f 100644
--- a/oap-server/server-cluster-plugin/cluster-etcd-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/etcd/EtcdCoordinator.java
+++ b/oap-server/server-cluster-plugin/cluster-etcd-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/etcd/EtcdCoordinator.java
@@ -37,7 +37,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class EtcdCoordinator implements ClusterRegister, ClusterNodesQuery {
-    private static final Logger logger = LoggerFactory.getLogger(EtcdCoordinator.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(EtcdCoordinator.class);
 
     private ClusterModuleEtcdConfig config;
 
@@ -119,7 +119,7 @@ public class EtcdCoordinator implements ClusterRegister, ClusterNodesQuery {
                 try {
                     client.put(key, json).ttl(KEY_TTL).send().get();
                 } catch (Exception ee) {
-                    logger.error(ee.getMessage(), ee);
+                    LOGGER.error(ee.getMessage(), ee);
                 }
             }
         }, 5 * 1000, 30 * 1000, TimeUnit.MILLISECONDS);
diff --git a/oap-server/server-cluster-plugin/cluster-standalone-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/standalone/ClusterModuleStandaloneProvider.java b/oap-server/server-cluster-plugin/cluster-standalone-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/standalone/ClusterModuleStandaloneProvider.java
index 4ca499a..7830eb3 100644
--- a/oap-server/server-cluster-plugin/cluster-standalone-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/standalone/ClusterModuleStandaloneProvider.java
+++ b/oap-server/server-cluster-plugin/cluster-standalone-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/standalone/ClusterModuleStandaloneProvider.java
@@ -30,7 +30,7 @@ import org.slf4j.LoggerFactory;
 
 public class ClusterModuleStandaloneProvider extends ModuleProvider {
 
-    private static final Logger logger = LoggerFactory.getLogger(ClusterModuleStandaloneProvider.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ClusterModuleStandaloneProvider.class);
 
     public ClusterModuleStandaloneProvider() {
         super();
diff --git a/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ClusterModuleZookeeperProvider.java b/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ClusterModuleZookeeperProvider.java
index d528135..303dad9 100644
--- a/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ClusterModuleZookeeperProvider.java
+++ b/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ClusterModuleZookeeperProvider.java
@@ -49,7 +49,7 @@ import org.slf4j.LoggerFactory;
  */
 public class ClusterModuleZookeeperProvider extends ModuleProvider {
 
-    private static final Logger logger = LoggerFactory.getLogger(ClusterModuleZookeeperProvider.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ClusterModuleZookeeperProvider.class);
 
     private static final String BASE_PATH = "/skywalking";
 
@@ -132,7 +132,7 @@ public class ClusterModuleZookeeperProvider extends ModuleProvider {
             serviceDiscovery.start();
             coordinator = new ZookeeperCoordinator(config, serviceDiscovery);
         } catch (Exception e) {
-            logger.error(e.getMessage(), e);
+            LOGGER.error(e.getMessage(), e);
             throw new ModuleStartException(e.getMessage(), e);
         }
 
diff --git a/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ZookeeperCoordinator.java b/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ZookeeperCoordinator.java
index 2fbdf07..e5452b3 100644
--- a/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ZookeeperCoordinator.java
+++ b/oap-server/server-cluster-plugin/cluster-zookeeper-plugin/src/main/java/org/apache/skywalking/oap/server/cluster/plugin/zookeeper/ZookeeperCoordinator.java
@@ -34,7 +34,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class ZookeeperCoordinator implements ClusterRegister, ClusterNodesQuery {
-    private static final Logger logger = LoggerFactory.getLogger(ZookeeperCoordinator.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ZookeeperCoordinator.class);
 
     private static final String REMOTE_NAME_PATH = "remote";
 
diff --git a/oap-server/server-configuration/configuration-api/src/main/java/org/apache/skywalking/oap/server/configuration/api/ConfigWatcherRegister.java b/oap-server/server-configuration/configuration-api/src/main/java/org/apache/skywalking/oap/server/configuration/api/ConfigWatcherRegister.java
index c4a436d..1c95d23 100644
--- a/oap-server/server-configuration/configuration-api/src/main/java/org/apache/skywalking/oap/server/configuration/api/ConfigWatcherRegister.java
+++ b/oap-server/server-configuration/configuration-api/src/main/java/org/apache/skywalking/oap/server/configuration/api/ConfigWatcherRegister.java
@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
  * The default implementor of Config Watcher register.
  */
 public abstract class ConfigWatcherRegister implements DynamicConfigurationService {
-    private static final Logger logger = LoggerFactory.getLogger(ConfigWatcherRegister.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ConfigWatcherRegister.class);
     public static final String LINE_SEPARATOR = System.getProperty("line.separator", "\n");
 
     private Register register = new Register();
@@ -65,13 +65,13 @@ public abstract class ConfigWatcherRegister implements DynamicConfigurationServi
         isStarted = true;
 
         configSync();
-        logger.info("Current configurations after the bootstrap sync." + LINE_SEPARATOR + register.toString());
+        LOGGER.info("Current configurations after the bootstrap sync." + LINE_SEPARATOR + register.toString());
 
         Executors.newSingleThreadScheduledExecutor()
                  .scheduleAtFixedRate(
                      new RunnableWithExceptionProtection(
                          this::configSync,
-                         t -> logger.error("Sync config center error.", t)
+                         t -> LOGGER.error("Sync config center error.", t)
                      ), syncPeriod, syncPeriod, TimeUnit.SECONDS);
     }
 
@@ -105,11 +105,11 @@ public abstract class ConfigWatcherRegister implements DynamicConfigurationServi
                         }
                     }
                 } else {
-                    logger.warn("Config {} from configuration center, doesn't match any watcher, ignore.", itemName);
+                    LOGGER.warn("Config {} from configuration center, doesn't match any watcher, ignore.", itemName);
                 }
             });
 
-            logger.trace("Current configurations after the sync." + LINE_SEPARATOR + register.toString());
+            LOGGER.trace("Current configurations after the sync." + LINE_SEPARATOR + register.toString());
         });
     }
 
diff --git a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigWatcherRegister.java b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigWatcherRegister.java
index aedb375..6123295 100644
--- a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigWatcherRegister.java
+++ b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigWatcherRegister.java
@@ -37,7 +37,7 @@ import org.slf4j.LoggerFactory;
 
 public class EtcdConfigWatcherRegister extends ConfigWatcherRegister {
 
-    private final static Logger logger = LoggerFactory.getLogger(EtcdConfigWatcherRegister.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(EtcdConfigWatcherRegister.class);
 
     /**
      * server settings for Etcd configuration
@@ -126,8 +126,8 @@ public class EtcdConfigWatcherRegister extends ConfigWatcherRegister {
         try {
             EtcdKeysResponse.EtcdNode node = promise.get().getNode();
             String value = node.getValue();
-            if (logger.isInfoEnabled()) {
-                logger.info("Etcd config changed: {}: {}", key, node.getValue());
+            if (LOGGER.isInfoEnabled()) {
+                LOGGER.info("Etcd config changed: {}: {}", key, node.getValue());
             }
 
             configItemKeyedByName.put(key, Optional.ofNullable(value));
diff --git a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigurationProvider.java b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigurationProvider.java
index a9fd4c6..fef0c4e 100644
--- a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigurationProvider.java
+++ b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdConfigurationProvider.java
@@ -31,7 +31,7 @@ import org.slf4j.LoggerFactory;
  */
 public class EtcdConfigurationProvider extends AbstractConfigurationProvider {
 
-    private final static Logger logger = LoggerFactory.getLogger(EtcdConfigurationProvider.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(EtcdConfigurationProvider.class);
 
     private EtcdServerSettings settings;
 
@@ -41,7 +41,7 @@ public class EtcdConfigurationProvider extends AbstractConfigurationProvider {
 
     @Override
     protected ConfigWatcherRegister initConfigReader() throws ModuleStartException {
-        logger.info("settings: {}", settings);
+        LOGGER.info("settings: {}", settings);
         if (Strings.isNullOrEmpty(settings.getServerAddr())) {
             throw new ModuleStartException("Etcd serverAddr cannot be null or empty.");
         }
diff --git a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdUtils.java b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdUtils.java
index 54b43ca..808b823 100644
--- a/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdUtils.java
+++ b/oap-server/server-configuration/configuration-etcd/src/main/java/org/apache/skywalking/oap/server/configuration/etcd/EtcdUtils.java
@@ -32,7 +32,7 @@ import org.slf4j.LoggerFactory;
  */
 public class EtcdUtils {
 
-    private final static Logger logger = LoggerFactory.getLogger(EtcdUtils.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(EtcdUtils.class);
 
     public EtcdUtils() {
     }
@@ -40,7 +40,7 @@ public class EtcdUtils {
     public static List<URI> parse(EtcdServerSettings settings) {
         List<URI> uris = new ArrayList<>();
         try {
-            logger.info("etcd settings is {}", settings);
+            LOGGER.info("etcd settings is {}", settings);
             List<Address> addressList = ConnectUtils.parse(settings.getServerAddr());
             for (Address address : addressList) {
                 uris.add(new URI("http", null, address.getHost(), address.getPort(), null, null, null));
@@ -55,7 +55,7 @@ public class EtcdUtils {
     public static List<URI> parseProp(Properties properties) {
         List<URI> uris = new ArrayList<>();
         try {
-            logger.info("etcd server addr is {}", properties);
+            LOGGER.info("etcd server addr is {}", properties);
             List<Address> addressList = ConnectUtils.parse(properties.getProperty("serverAddr"));
             for (Address address : addressList) {
                 uris.add(new URI("http", null, address.getHost(), address.getPort(), null, null, null));
diff --git a/oap-server/server-configuration/configuration-etcd/src/test/java/org/apache/skywalking/oap/server/configuration/etcd/ITEtcdConfigurationTest.java b/oap-server/server-configuration/configuration-etcd/src/test/java/org/apache/skywalking/oap/server/configuration/etcd/ITEtcdConfigurationTest.java
index 2f7342d..fa638a8 100644
--- a/oap-server/server-configuration/configuration-etcd/src/test/java/org/apache/skywalking/oap/server/configuration/etcd/ITEtcdConfigurationTest.java
+++ b/oap-server/server-configuration/configuration-etcd/src/test/java/org/apache/skywalking/oap/server/configuration/etcd/ITEtcdConfigurationTest.java
@@ -45,7 +45,7 @@ import static org.junit.Assert.assertTrue;
 
 public class ITEtcdConfigurationTest {
 
-    private static final Logger logger = LoggerFactory.getLogger(ITEtcdConfigurationTest.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ITEtcdConfigurationTest.class);
 
     private final Yaml yaml = new Yaml();
 
@@ -65,7 +65,7 @@ public class ITEtcdConfigurationTest {
 
         final String etcdHost = System.getProperty("etcd.host");
         final String etcdPort = System.getProperty("etcd.port");
-        logger.info("etcdHost: {}, etcdPort: {}", etcdHost, etcdPort);
+        LOGGER.info("etcdHost: {}, etcdPort: {}", etcdHost, etcdPort);
         Properties properties = new Properties();
         properties.setProperty("serverAddr", etcdHost + ":" + etcdPort);
 
@@ -84,7 +84,7 @@ public class ITEtcdConfigurationTest {
         assertTrue(publishConfig("test-module.default.testKey", "skywalking", "500"));
 
         for (String v = provider.watcher.value(); v == null; v = provider.watcher.value()) {
-            logger.info("value is : {}", provider.watcher.value());
+            LOGGER.info("value is : {}", provider.watcher.value());
         }
 
         assertEquals("500", provider.watcher.value());
diff --git a/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java b/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
index 9735459..edcfac7 100644
--- a/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
+++ b/oap-server/server-configuration/grpc-configuration-sync/src/main/java/org/apache/skywalking/oap/server/configuration/grpc/GRPCConfigWatcherRegister.java
@@ -31,7 +31,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class GRPCConfigWatcherRegister extends ConfigWatcherRegister {
-    private static final Logger logger = LoggerFactory.getLogger(GRPCConfigWatcherRegister.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GRPCConfigWatcherRegister.class);
 
     private RemoteEndpointSettings settings;
     private ConfigurationServiceGrpc.ConfigurationServiceBlockingStub stub;
@@ -68,7 +68,7 @@ public class GRPCConfigWatcherRegister extends ConfigWatcherRegister {
                 }
             });
         } catch (Exception e) {
-            logger.error("Remote config center [" + settings + "] is not available.", e);
+            LOGGER.error("Remote config center [" + settings + "] is not available.", e);
         }
         return Optional.of(table);
     }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/WorkPath.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/WorkPath.java
index 443bad5..532a9f3 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/WorkPath.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/WorkPath.java
@@ -29,7 +29,7 @@ import org.slf4j.LoggerFactory;
  * Locate the base work path of OAP backend.
  */
 public class WorkPath {
-    private static final Logger logger = LoggerFactory.getLogger(WorkPath.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(WorkPath.class);
 
     private static File PATH;
 
@@ -47,7 +47,7 @@ public class WorkPath {
         if (resource != null) {
             String urlString = resource.toString();
 
-            logger.debug("The beacon class location is {}.", urlString);
+            LOGGER.debug("The beacon class location is {}.", urlString);
 
             int insidePathIndex = urlString.indexOf('!');
             boolean isInJar = insidePathIndex > -1;
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/alarm/AlarmStandardPersistence.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/alarm/AlarmStandardPersistence.java
index 6216bc1..059bf43 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/alarm/AlarmStandardPersistence.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/alarm/AlarmStandardPersistence.java
@@ -29,13 +29,13 @@ import org.slf4j.LoggerFactory;
  */
 public class AlarmStandardPersistence implements AlarmCallback {
 
-    private static final Logger logger = LoggerFactory.getLogger(AlarmStandardPersistence.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(AlarmStandardPersistence.class);
 
     @Override
     public void doAlarm(List<AlarmMessage> alarmMessage) {
         alarmMessage.forEach(message -> {
-            if (logger.isDebugEnabled()) {
-                logger.debug("Alarm message: {}", message.getAlarmMessage());
+            if (LOGGER.isDebugEnabled()) {
+                LOGGER.debug("Alarm message: {}", message.getAlarmMessage());
             }
 
             AlarmRecord record = new AlarmRecord();
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/DispatcherManager.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/DispatcherManager.java
index 82d1ad8..059d3b0 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/DispatcherManager.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/DispatcherManager.java
@@ -34,7 +34,7 @@ import org.slf4j.LoggerFactory;
 
 public class DispatcherManager implements DispatcherDetectorListener {
 
-    private static final Logger logger = LoggerFactory.getLogger(DispatcherManager.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(DispatcherManager.class);
 
     private Map<Integer, List<SourceDispatcher>> dispatcherMap;
 
@@ -112,7 +112,7 @@ public class DispatcherManager implements DispatcherDetectorListener {
 
                     dispatchers.add(dispatcher);
 
-                    logger.info("Dispatcher {} is added into DefaultScopeDefine {}.", dispatcher.getClass()
+                    LOGGER.info("Dispatcher {} is added into DefaultScopeDefine {}.", dispatcher.getClass()
                                                                                                 .getName(), scopeId);
                 }
             }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/RecordPersistentWorker.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/RecordPersistentWorker.java
index 7cfeef8..9c5f8be 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/RecordPersistentWorker.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/analysis/worker/RecordPersistentWorker.java
@@ -32,7 +32,7 @@ import org.slf4j.LoggerFactory;
 
 public class RecordPersistentWorker extends AbstractWorker<Record> {
 
-    private static final Logger logger = LoggerFactory.getLogger(RecordPersistentWorker.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RecordPersistentWorker.class);
 
     private final Model model;
     private final IRecordDAO recordDAO;
@@ -51,7 +51,7 @@ public class RecordPersistentWorker extends AbstractWorker<Record> {
             InsertRequest insertRequest = recordDAO.prepareBatchInsert(model, record);
             batchDAO.asynchronous(insertRequest);
         } catch (IOException e) {
-            logger.error(e.getMessage(), e);
+            LOGGER.error(e.getMessage(), e);
         }
     }
 }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/ComponentLibraryCatalogService.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/ComponentLibraryCatalogService.java
index 731da18..aac4ffe 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/ComponentLibraryCatalogService.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/config/ComponentLibraryCatalogService.java
@@ -32,7 +32,7 @@ import org.yaml.snakeyaml.Yaml;
  * which declare the real server type based on client component.
  */
 public class ComponentLibraryCatalogService implements IComponentLibraryCatalogService {
-    private static final Logger logger = LoggerFactory.getLogger(ComponentLibraryCatalogService.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ComponentLibraryCatalogService.class);
     private static final String COMPONENT_SERVER_MAPPING_SECTION = "Component-Server-Mappings";
 
     private Map<String, Integer> componentName2Id;
@@ -107,7 +107,7 @@ public class ComponentLibraryCatalogService implements IComponentLibraryCatalogS
             });
             nameMapping.clear();
         } catch (FileNotFoundException e) {
-            logger.error("component-libraries.yml not found.", e);
+            LOGGER.error("component-libraries.yml not found.", e);
         }
 
     }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteSenderService.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteSenderService.java
index cd4a54e..e0ff100 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteSenderService.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteSenderService.java
@@ -37,7 +37,7 @@ import org.slf4j.LoggerFactory;
  * provides several routing mode to select target OAP node.
  */
 public class RemoteSenderService implements Service {
-    private static final Logger logger = LoggerFactory.getLogger(RemoteSenderService.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteSenderService.class);
 
     private final ModuleManager moduleManager;
     private final HashCodeSelector hashCodeSelector;
@@ -66,7 +66,7 @@ public class RemoteSenderService implements Service {
 
         List<RemoteClient> clientList = clientManager.getRemoteClient();
         if (clientList.size() == 0) {
-            logger.warn(
+            LOGGER.warn(
                 "There is no available remote server for now, ignore the streaming data until the cluster metadata initialized.");
             return;
         }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteServiceHandler.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteServiceHandler.java
index 9fa2e50..2a37193 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteServiceHandler.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/RemoteServiceHandler.java
@@ -46,7 +46,7 @@ import org.slf4j.LoggerFactory;
  */
 public class RemoteServiceHandler extends RemoteServiceGrpc.RemoteServiceImplBase implements GRPCHandler {
 
-    private static final Logger logger = LoggerFactory.getLogger(RemoteServiceHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteServiceHandler.class);
 
     private final ModuleDefineHolder moduleDefineHolder;
     private IWorkerInstanceGetter workerInstanceGetter;
@@ -125,14 +125,14 @@ public class RemoteServiceHandler extends RemoteServiceGrpc.RemoteServiceImplBas
                             nextWorker.in(streamData);
                         } else {
                             remoteInTargetNotFoundCounter.inc();
-                            logger.warn(
+                            LOGGER.warn(
                                 "Work name [{}] not found. Check OAL script, make sure they are same in the whole cluster.",
                                 nextWorkerName
                             );
                         }
                     } catch (Throwable t) {
                         remoteInErrorCounter.inc();
-                        logger.error(t.getMessage(), t);
+                        LOGGER.error(t.getMessage(), t);
                     }
                 } finally {
                     timer.finish();
@@ -141,7 +141,7 @@ public class RemoteServiceHandler extends RemoteServiceGrpc.RemoteServiceImplBas
 
             @Override
             public void onError(Throwable throwable) {
-                logger.error(throwable.getMessage(), throwable);
+                LOGGER.error(throwable.getMessage(), throwable);
             }
 
             @Override
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java
index 21bf88e..59a89b9 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/GRPCRemoteClient.java
@@ -46,7 +46,7 @@ import org.slf4j.LoggerFactory;
  */
 public class GRPCRemoteClient implements RemoteClient {
 
-    private static final Logger logger = LoggerFactory.getLogger(GRPCRemoteClient.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GRPCRemoteClient.class);
 
     private final int channelSize;
     private final int bufferSize;
@@ -160,13 +160,13 @@ public class GRPCRemoteClient implements RemoteClient {
                 streamObserver.onCompleted();
             } catch (Throwable t) {
                 remoteOutErrorCounter.inc();
-                logger.error(t.getMessage(), t);
+                LOGGER.error(t.getMessage(), t);
             }
         }
 
         @Override
         public void onError(List<RemoteMessage> remoteMessages, Throwable t) {
-            logger.error(t.getMessage(), t);
+            LOGGER.error(t.getMessage(), t);
         }
 
         @Override
@@ -189,13 +189,13 @@ public class GRPCRemoteClient implements RemoteClient {
             try {
                 Thread.sleep(sleepMillis);
             } catch (InterruptedException e) {
-                logger.error(e.getMessage(), e);
+                LOGGER.error(e.getMessage(), e);
             }
 
             sleepTotalMillis += sleepMillis;
 
             if (sleepTotalMillis > 60000) {
-                logger.warn("Remote client block times over 60 seconds.");
+                LOGGER.warn("Remote client block times over 60 seconds.");
             }
         }
 
@@ -207,7 +207,7 @@ public class GRPCRemoteClient implements RemoteClient {
             @Override
             public void onError(Throwable throwable) {
                 concurrentStreamObserverNumber.addAndGet(-1);
-                logger.error(throwable.getMessage(), throwable);
+                LOGGER.error(throwable.getMessage(), throwable);
             }
 
             @Override
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/RemoteClientManager.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/RemoteClientManager.java
index 7470204..94af86e 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/RemoteClientManager.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/client/RemoteClientManager.java
@@ -56,7 +56,7 @@ import org.slf4j.LoggerFactory;
  */
 public class RemoteClientManager implements Service {
 
-    private static final Logger logger = LoggerFactory.getLogger(RemoteClientManager.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteClientManager.class);
 
     private final ModuleDefineHolder moduleDefineHolder;
     private SslContext sslContext;
@@ -121,8 +121,8 @@ public class RemoteClientManager implements Service {
                 }
             }
 
-            if (logger.isDebugEnabled()) {
-                logger.debug("Refresh remote nodes collection.");
+            if (LOGGER.isDebugEnabled()) {
+                LOGGER.debug("Refresh remote nodes collection.");
             }
 
             List<RemoteInstance> instanceList = clusterNodesQuery.queryRemoteNodes();
@@ -131,20 +131,20 @@ public class RemoteClientManager implements Service {
 
             gauge.setValue(instanceList.size());
 
-            if (logger.isDebugEnabled()) {
-                instanceList.forEach(instance -> logger.debug("Cluster instance: {}", instance.toString()));
+            if (LOGGER.isDebugEnabled()) {
+                instanceList.forEach(instance -> LOGGER.debug("Cluster instance: {}", instance.toString()));
             }
 
             if (!compare(instanceList)) {
-                if (logger.isDebugEnabled()) {
-                    logger.debug("ReBuilding remote clients.");
+                if (LOGGER.isDebugEnabled()) {
+                    LOGGER.debug("ReBuilding remote clients.");
                 }
                 reBuildRemoteClients(instanceList);
             }
 
             printRemoteClientList();
         } catch (Throwable t) {
-            logger.error(t.getMessage(), t);
+            LOGGER.error(t.getMessage(), t);
         }
     }
 
@@ -152,10 +152,10 @@ public class RemoteClientManager implements Service {
      * Print the client list into log for confirm how many clients built.
      */
     private void printRemoteClientList() {
-        if (logger.isDebugEnabled()) {
+        if (LOGGER.isDebugEnabled()) {
             StringBuilder addresses = new StringBuilder();
             this.usingClients.forEach(client -> addresses.append(client.getAddress().toString()).append(","));
-            logger.debug("Remote client list: {}", addresses);
+            LOGGER.debug("Remote client list: {}", addresses);
         }
     }
 
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/health/HealthCheckServiceHandler.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/health/HealthCheckServiceHandler.java
index 7b83dcb..53a8776 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/health/HealthCheckServiceHandler.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/health/HealthCheckServiceHandler.java
@@ -27,7 +27,7 @@ import org.slf4j.LoggerFactory;
 
 public class HealthCheckServiceHandler extends HealthGrpc.HealthImplBase implements GRPCHandler {
 
-    private static final Logger logger = LoggerFactory.getLogger(HealthCheckServiceHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(HealthCheckServiceHandler.class);
 
     /**
      * By my test, consul didn't send the service.
@@ -39,8 +39,8 @@ public class HealthCheckServiceHandler extends HealthGrpc.HealthImplBase impleme
     public void check(HealthCheckService.HealthCheckRequest request,
         StreamObserver<HealthCheckService.HealthCheckResponse> responseObserver) {
 
-        if (logger.isDebugEnabled()) {
-            logger.debug("Received the gRPC server health check with the service name of {}", request.getService());
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug("Received the gRPC server health check with the service name of {}", request.getService());
         }
 
         HealthCheckService.HealthCheckResponse.Builder response = HealthCheckService.HealthCheckResponse.newBuilder();
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/selector/ForeverFirstSelector.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/selector/ForeverFirstSelector.java
index 81a8800..1c649be 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/selector/ForeverFirstSelector.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/remote/selector/ForeverFirstSelector.java
@@ -26,12 +26,12 @@ import org.slf4j.LoggerFactory;
 
 public class ForeverFirstSelector implements RemoteClientSelector {
 
-    private static final Logger logger = LoggerFactory.getLogger(ForeverFirstSelector.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ForeverFirstSelector.class);
 
     @Override
     public RemoteClient select(List<RemoteClient> clients, StreamData streamData) {
-        if (logger.isDebugEnabled()) {
-            logger.debug("clients size: {}", clients.size());
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug("clients size: {}", clients.size());
         }
         return clients.get(0);
     }
diff --git a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/worker/WorkerInstancesService.java b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/worker/WorkerInstancesService.java
index ec44783..1647610 100644
--- a/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/worker/WorkerInstancesService.java
+++ b/oap-server/server-core/src/main/java/org/apache/skywalking/oap/server/core/worker/WorkerInstancesService.java
@@ -29,7 +29,7 @@ import org.slf4j.LoggerFactory;
  * Worker Instance Service hosts all remote handler workers with the stream data type.
  */
 public class WorkerInstancesService implements IWorkerInstanceSetter, IWorkerInstanceGetter {
-    private static final Logger logger = LoggerFactory.getLogger(WorkerInstancesService.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(WorkerInstancesService.class);
 
     private final Map<String, RemoteHandleWorker> instances;
 
@@ -49,6 +49,6 @@ public class WorkerInstancesService implements IWorkerInstanceSetter, IWorkerIns
             throw new UnexpectedException("Duplicate worker name:" + remoteReceiverWorkName);
         }
         instances.put(remoteReceiverWorkName, new RemoteHandleWorker(instance, streamDataClass));
-        logger.debug("Worker {} has been registered as {}", instance.toString(), remoteReceiverWorkName);
+        LOGGER.debug("Worker {} has been registered as {}", instance.toString(), remoteReceiverWorkName);
     }
 }
diff --git a/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/grpc/GRPCClient.java b/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/grpc/GRPCClient.java
index 91bef88..c11f590 100644
--- a/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/grpc/GRPCClient.java
+++ b/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/grpc/GRPCClient.java
@@ -29,7 +29,7 @@ import org.slf4j.LoggerFactory;
 
 public class GRPCClient implements Client {
 
-    private static final Logger logger = LoggerFactory.getLogger(GRPCClient.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GRPCClient.class);
 
     @Getter
     private final String host;
@@ -65,7 +65,7 @@ public class GRPCClient implements Client {
         try {
             channel.shutdownNow();
         } catch (Throwable t) {
-            logger.error(t.getMessage(), t);
+            LOGGER.error(t.getMessage(), t);
         }
     }
 
diff --git a/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/jdbc/hikaricp/JDBCHikariCPClient.java b/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/jdbc/hikaricp/JDBCHikariCPClient.java
index d02ef46..502eed3 100644
--- a/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/jdbc/hikaricp/JDBCHikariCPClient.java
+++ b/oap-server/server-library/library-client/src/main/java/org/apache/skywalking/oap/server/library/client/jdbc/hikaricp/JDBCHikariCPClient.java
@@ -38,7 +38,7 @@ import org.slf4j.LoggerFactory;
  * JDBC Client uses HikariCP connection management lib to execute SQL.
  */
 public class JDBCHikariCPClient implements Client, HealthCheckable {
-    private static final Logger logger = LoggerFactory.getLogger(JDBCHikariCPClient.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JDBCHikariCPClient.class);
 
     private final HikariConfig hikariConfig;
     private final DelegatedHealthChecker healthChecker;
@@ -80,7 +80,7 @@ public class JDBCHikariCPClient implements Client, HealthCheckable {
     }
 
     public void execute(Connection connection, String sql) throws JDBCClientException {
-        logger.debug("execute aql: {}", sql);
+        LOGGER.debug("execute aql: {}", sql);
         try (Statement statement = connection.createStatement()) {
             statement.execute(sql);
             healthChecker.health();
@@ -91,7 +91,7 @@ public class JDBCHikariCPClient implements Client, HealthCheckable {
     }
 
     public boolean execute(Connection connection, String sql, Object... params) throws JDBCClientException {
-        logger.debug("execute query with result: {}", sql);
+        LOGGER.debug("execute query with result: {}", sql);
         boolean result;
         PreparedStatement statement = null;
         try {
@@ -115,7 +115,7 @@ public class JDBCHikariCPClient implements Client, HealthCheckable {
     }
 
     public ResultSet executeQuery(Connection connection, String sql, Object... params) throws JDBCClientException {
-        logger.debug("execute query with result: {}", sql);
+        LOGGER.debug("execute query with result: {}", sql);
         ResultSet rs;
         PreparedStatement statement = null;
         try {
diff --git a/oap-server/server-library/library-client/src/test/java/org/apache/skywalking/oap/server/library/client/elasticsearch/ITElasticSearchClient.java b/oap-server/server-library/library-client/src/test/java/org/apache/skywalking/oap/server/library/client/elasticsearch/ITElasticSearchClient.java
index c18bdff..2466d53 100644
--- a/oap-server/server-library/library-client/src/test/java/org/apache/skywalking/oap/server/library/client/elasticsearch/ITElasticSearchClient.java
+++ b/oap-server/server-library/library-client/src/test/java/org/apache/skywalking/oap/server/library/client/elasticsearch/ITElasticSearchClient.java
@@ -50,7 +50,7 @@ import org.slf4j.LoggerFactory;
 
 public class ITElasticSearchClient {
 
-    private static final Logger logger = LoggerFactory.getLogger(ITElasticSearchClient.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ITElasticSearchClient.class);
 
     private ElasticSearchClient client;
 
@@ -99,7 +99,7 @@ public class ITElasticSearchClient {
         Assert.assertTrue(client.isExistsIndex(indexName));
 
         JsonObject index = getIndex(indexName);
-        logger.info(index.toString());
+        LOGGER.info(index.toString());
 
         Assert.assertEquals(2, index.getAsJsonObject(indexName)
                                     .getAsJsonObject("settings")
@@ -184,7 +184,7 @@ public class ITElasticSearchClient {
         client.forceInsert(indexName + "-2019", "testid", builder);
 
         JsonObject index = getIndex(indexName + "-2019");
-        logger.info(index.toString());
+        LOGGER.info(index.toString());
 
         Assert.assertEquals(1, index.getAsJsonObject(indexName + "-2019")
                                     .getAsJsonObject("settings")
@@ -265,7 +265,7 @@ public class ITElasticSearchClient {
 
     private JsonObject undoFormatIndexName(JsonObject index) {
         if (StringUtil.isNotEmpty(namespace) && index != null && index.size() > 0) {
-            logger.info("UndoFormatIndexName before " + index.toString());
+            LOGGER.info("UndoFormatIndexName before " + index.toString());
             String namespacePrefix = namespace + "_";
             index.entrySet().forEach(entry -> {
                 String oldIndexName = entry.getKey();
@@ -278,7 +278,7 @@ public class ITElasticSearchClient {
                             .getKey());
                 }
             });
-            logger.info("UndoFormatIndexName after " + index.toString());
+            LOGGER.info("UndoFormatIndexName after " + index.toString());
         }
         return index;
     }
diff --git a/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/BootstrapFlow.java b/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/BootstrapFlow.java
index 5abda34..a5ac9be 100644
--- a/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/BootstrapFlow.java
+++ b/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/BootstrapFlow.java
@@ -27,7 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 class BootstrapFlow {
-    private static final Logger logger = LoggerFactory.getLogger(BootstrapFlow.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(BootstrapFlow.class);
 
     private Map<String, ModuleDefine> loadedModules;
     private List<ModuleProvider> startupSequence;
@@ -52,7 +52,7 @@ class BootstrapFlow {
                     }
                 }
             }
-            logger.info("start the provider {} in {} module.", provider.name(), provider.getModuleName());
+            LOGGER.info("start the provider {} in {} module.", provider.name(), provider.getModuleName());
             provider.requiredCheck(provider.getModule().services());
 
             provider.start();
diff --git a/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/ModuleDefine.java b/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/ModuleDefine.java
index 9839ca8..e9c7b97 100644
--- a/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/ModuleDefine.java
+++ b/oap-server/server-library/library-module/src/main/java/org/apache/skywalking/oap/server/library/module/ModuleDefine.java
@@ -30,7 +30,7 @@ import org.slf4j.LoggerFactory;
  */
 public abstract class ModuleDefine implements ModuleProviderHolder {
 
-    private static final Logger logger = LoggerFactory.getLogger(ModuleDefine.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ModuleDefine.class);
 
     private ModuleProvider loadedProvider = null;
 
@@ -42,6 +42,7 @@ public abstract class ModuleDefine implements ModuleProviderHolder {
 
     /**
      * @return the module name
+     *
      */
     public final String name() {
         return name;
@@ -85,7 +86,7 @@ public abstract class ModuleDefine implements ModuleProviderHolder {
             throw new ProviderNotFoundException(this.name() + " module no provider exists.");
         }
 
-        logger.info("Prepare the {} provider in {} module.", loadedProvider.name(), this.name());
+        LOGGER.info("Prepare the {} provider in {} module.", loadedProvider.name(), this.name());
         try {
             copyProperties(loadedProvider.createConfigBeanIfAbsent(), configuration.getProviderConfiguration(loadedProvider
                 .name()), this.name(), loadedProvider.name());
@@ -109,7 +110,7 @@ public abstract class ModuleDefine implements ModuleProviderHolder {
                 field.setAccessible(true);
                 field.set(dest, src.get(propertyName));
             } catch (NoSuchFieldException e) {
-                logger.warn(propertyName + " setting is not supported in " + providerName + " provider of " + moduleName + " module");
+                LOGGER.warn(propertyName + " setting is not supported in " + providerName + " provider of " + moduleName + " module");
             }
         }
     }
diff --git a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/grpc/GRPCServer.java b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/grpc/GRPCServer.java
index e952b21..d2eb9ac 100644
--- a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/grpc/GRPCServer.java
+++ b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/grpc/GRPCServer.java
@@ -40,7 +40,7 @@ import org.slf4j.LoggerFactory;
 
 public class GRPCServer implements Server {
 
-    private static final Logger logger = LoggerFactory.getLogger(GRPCServer.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GRPCServer.class);
 
     private final String host;
     private final int port;
@@ -109,14 +109,14 @@ public class GRPCServer implements Server {
         nettyServerBuilder = nettyServerBuilder.maxConcurrentCallsPerConnection(maxConcurrentCallsPerConnection)
                                                .maxInboundMessageSize(maxMessageSize)
                                                .executor(executor);
-        logger.info("Server started, host {} listening on {}", host, port);
+        LOGGER.info("Server started, host {} listening on {}", host, port);
     }
 
     static class CustomRejectedExecutionHandler implements RejectedExecutionHandler {
 
         @Override
         public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
-            logger.warn("Grpc server thread pool is full, rejecting the task");
+            LOGGER.warn("Grpc server thread pool is full, rejecting the task");
         }
     }
 
@@ -135,12 +135,12 @@ public class GRPCServer implements Server {
     }
 
     public void addHandler(BindableService handler) {
-        logger.info("Bind handler {} into gRPC server {}:{}", handler.getClass().getSimpleName(), host, port);
+        LOGGER.info("Bind handler {} into gRPC server {}:{}", handler.getClass().getSimpleName(), host, port);
         nettyServerBuilder.addService(handler);
     }
 
     public void addHandler(ServerServiceDefinition definition) {
-        logger.info("Bind handler {} into gRPC server {}:{}", definition.getClass().getSimpleName(), host, port);
+        LOGGER.info("Bind handler {} into gRPC server {}:{}", definition.getClass().getSimpleName(), host, port);
         nettyServerBuilder.addService(definition);
     }
 
diff --git a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyJsonHandler.java b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyJsonHandler.java
index b48a324..138106c 100644
--- a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyJsonHandler.java
+++ b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyJsonHandler.java
@@ -36,7 +36,7 @@ import org.slf4j.LoggerFactory;
 import static java.util.Objects.nonNull;
 
 public abstract class JettyJsonHandler extends JettyHandler {
-    private static final Logger logger = LoggerFactory.getLogger(JettyJsonHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JettyJsonHandler.class);
 
     @Override
     protected final void doGet(HttpServletRequest req, HttpServletResponse resp) {
@@ -46,7 +46,7 @@ public abstract class JettyJsonHandler extends JettyHandler {
             try {
                 replyError(resp, e.getMessage(), HttpServletResponse.SC_BAD_REQUEST);
             } catch (IOException replyException) {
-                logger.error(replyException.getMessage(), e);
+                LOGGER.error(replyException.getMessage(), e);
             }
         }
     }
@@ -61,7 +61,7 @@ public abstract class JettyJsonHandler extends JettyHandler {
             try {
                 replyError(resp, e.getMessage(), HttpServletResponse.SC_BAD_REQUEST);
             } catch (IOException replyException) {
-                logger.error(replyException.getMessage(), e);
+                LOGGER.error(replyException.getMessage(), e);
             }
         }
     }
diff --git a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyServer.java b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyServer.java
index 48ab1fe..d4e3741 100644
--- a/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyServer.java
+++ b/oap-server/server-library/library-server/src/main/java/org/apache/skywalking/oap/server/library/server/jetty/JettyServer.java
@@ -32,7 +32,7 @@ import org.slf4j.LoggerFactory;
 
 public class JettyServer implements Server {
 
-    private static final Logger logger = LoggerFactory.getLogger(JettyServer.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JettyServer.class);
 
     private org.eclipse.jetty.server.Server server;
     private ServletContextHandler servletContextHandler;
@@ -70,13 +70,13 @@ public class JettyServer implements Server {
 
         servletContextHandler = new ServletContextHandler(ServletContextHandler.NO_SESSIONS);
         servletContextHandler.setContextPath(jettyServerConfig.getContextPath());
-        logger.info("http server root context path: {}", jettyServerConfig.getContextPath());
+        LOGGER.info("http server root context path: {}", jettyServerConfig.getContextPath());
 
         server.setHandler(servletContextHandler);
     }
 
     public void addHandler(JettyHandler handler) {
-        logger.info(
+        LOGGER.info(
             "Bind handler {} into jetty server {}:{}",
             handler.getClass().getSimpleName(), jettyServerConfig.getHost(), jettyServerConfig.getPort()
         );
@@ -98,14 +98,14 @@ public class JettyServer implements Server {
 
     @Override
     public void start() throws ServerException {
-        logger.info("start server, host: {}, port: {}", jettyServerConfig.getHost(), jettyServerConfig.getPort());
+        LOGGER.info("start server, host: {}, port: {}", jettyServerConfig.getHost(), jettyServerConfig.getPort());
         try {
-            if (logger.isDebugEnabled()) {
+            if (LOGGER.isDebugEnabled()) {
                 if (servletContextHandler.getServletHandler() != null && servletContextHandler.getServletHandler()
                                                                                               .getServletMappings() != null) {
                     for (ServletMapping servletMapping : servletContextHandler.getServletHandler()
                                                                               .getServletMappings()) {
-                        logger.debug(
+                        LOGGER.debug(
                             "jetty servlet mappings: {} register by {}", servletMapping.getPathSpecs(), servletMapping
                                 .getServletName());
                     }
diff --git a/oap-server/server-library/library-util/src/test/java/org/apache/skywalking/oap/server/library/util/TimestampUtils.java b/oap-server/server-library/library-util/src/test/java/org/apache/skywalking/oap/server/library/util/TimestampUtils.java
index 7d991f9..6bb944b 100644
--- a/oap-server/server-library/library-util/src/test/java/org/apache/skywalking/oap/server/library/util/TimestampUtils.java
+++ b/oap-server/server-library/library-util/src/test/java/org/apache/skywalking/oap/server/library/util/TimestampUtils.java
@@ -25,11 +25,11 @@ import org.slf4j.LoggerFactory;
 
 public class TimestampUtils {
 
-    private static final Logger logger = LoggerFactory.getLogger(TimestampUtils.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(TimestampUtils.class);
 
     public static void main(String[] args) {
         SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
         Timestamp timestamp = new Timestamp(1483200061001L);
-        logger.info("time: {}", format.format(timestamp));
+        LOGGER.info("time: {}", format.format(timestamp));
     }
 }
diff --git a/oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/GraphQLQueryHandler.java b/oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/GraphQLQueryHandler.java
index d6da7be..ca447c6 100644
--- a/oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/GraphQLQueryHandler.java
+++ b/oap-server/server-query-plugin/query-graphql-plugin/src/main/java/org/apache/skywalking/oap/query/graphql/GraphQLQueryHandler.java
@@ -43,7 +43,7 @@ import org.slf4j.LoggerFactory;
 @RequiredArgsConstructor
 public class GraphQLQueryHandler extends JettyJsonHandler {
 
-    private static final Logger logger = LoggerFactory.getLogger(GraphQLQueryHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(GraphQLQueryHandler.class);
 
     private static final String QUERY = "query";
     private static final String VARIABLES = "variables";
@@ -91,7 +91,7 @@ public class GraphQLQueryHandler extends JettyJsonHandler {
                                                           .variables(variables)
                                                           .build();
             ExecutionResult executionResult = graphQL.execute(executionInput);
-            logger.debug("Execution result is {}", executionResult);
+            LOGGER.debug("Execution result is {}", executionResult);
             Object data = executionResult.getData();
             List<GraphQLError> errors = executionResult.getErrors();
             JsonObject jsonObject = new JsonObject();
@@ -110,7 +110,7 @@ public class GraphQLQueryHandler extends JettyJsonHandler {
             }
             return jsonObject;
         } catch (final Throwable e) {
-            logger.error(e.getMessage(), e);
+            LOGGER.error(e.getMessage(), e);
             JsonObject jsonObject = new JsonObject();
             JsonArray errorArray = new JsonArray();
             JsonObject errorJson = new JsonObject();
diff --git a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/AccessLogServiceGRPCHandler.java b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/AccessLogServiceGRPCHandler.java
index 61f562b..b715ee3 100644
--- a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/AccessLogServiceGRPCHandler.java
+++ b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/AccessLogServiceGRPCHandler.java
@@ -40,7 +40,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class AccessLogServiceGRPCHandler extends AccessLogServiceGrpc.AccessLogServiceImplBase {
-    private static final Logger logger = LoggerFactory.getLogger(AccessLogServiceGRPCHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(AccessLogServiceGRPCHandler.class);
     private final List<ALSHTTPAnalysis> envoyHTTPAnalysisList;
     private final SourceReceiver sourceReceiver;
     private final CounterMetrics counter;
@@ -59,7 +59,7 @@ public class AccessLogServiceGRPCHandler extends AccessLogServiceGrpc.AccessLogS
             }
         }
 
-        logger.debug("envoy HTTP analysis: " + envoyHTTPAnalysisList);
+        LOGGER.debug("envoy HTTP analysis: " + envoyHTTPAnalysisList);
 
         sourceReceiver = manager.find(CoreModule.NAME).provider().getService(SourceReceiver.class);
 
@@ -93,8 +93,8 @@ public class AccessLogServiceGRPCHandler extends AccessLogServiceGrpc.AccessLogS
 
                     StreamAccessLogsMessage.LogEntriesCase logCase = message.getLogEntriesCase();
 
-                    if (logger.isDebugEnabled()) {
-                        logger.debug("Messaged is identified from Envoy[{}], role[{}] in [{}]. Received msg {}", identifier
+                    if (LOGGER.isDebugEnabled()) {
+                        LOGGER.debug("Messaged is identified from Envoy[{}], role[{}] in [{}]. Received msg {}", identifier
                             .getNode()
                             .getId(), role, logCase, message);
                     }
@@ -120,7 +120,7 @@ public class AccessLogServiceGRPCHandler extends AccessLogServiceGrpc.AccessLogS
 
             @Override
             public void onError(Throwable throwable) {
-                logger.error("Error in receiving access log from envoy", throwable);
+                LOGGER.error("Error in receiving access log from envoy", throwable);
                 responseObserver.onCompleted();
             }
 
diff --git a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/Fetcher.java b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/Fetcher.java
index 1d40d7c..94a27d0 100644
--- a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/Fetcher.java
+++ b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/Fetcher.java
@@ -29,7 +29,7 @@ import org.slf4j.LoggerFactory;
 
 interface Fetcher extends Function<V1OwnerReference, Optional<V1ObjectMeta>> {
 
-    Logger logger = LoggerFactory.getLogger(Fetcher.class);
+    Logger LOGGER = LoggerFactory.getLogger(Fetcher.class);
 
     V1ObjectMeta go(V1OwnerReference ownerReference) throws ApiException;
 
@@ -37,10 +37,10 @@ interface Fetcher extends Function<V1OwnerReference, Optional<V1ObjectMeta>> {
         try {
             return Optional.ofNullable(go(ownerReference));
         } catch (final ApiException e) {
-            logger.error("code:{} header:{} body:{}", e.getCode(), e.getResponseHeaders(), e.getResponseBody());
+            LOGGER.error("code:{} header:{} body:{}", e.getCode(), e.getResponseHeaders(), e.getResponseBody());
             return Optional.empty();
         } catch (final Throwable th) {
-            logger.error("other errors", th);
+            LOGGER.error("other errors", th);
             return Optional.empty();
         }
     }
diff --git a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/K8sALSServiceMeshHTTPAnalysis.java b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/K8sALSServiceMeshHTTPAnalysis.java
index b1d8d98..287e98a 100644
--- a/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/K8sALSServiceMeshHTTPAnalysis.java
+++ b/oap-server/server-receiver-plugin/envoy-metrics-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/envoy/als/K8sALSServiceMeshHTTPAnalysis.java
@@ -62,7 +62,7 @@ import org.slf4j.LoggerFactory;
  * Analysis log based on ingress and mesh scenarios.
  */
 public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
-    private static final Logger logger = LoggerFactory.getLogger(K8sALSServiceMeshHTTPAnalysis.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(K8sALSServiceMeshHTTPAnalysis.class);
 
     private static final String ADDRESS_TYPE_INTERNAL_IP = "InternalIP";
 
@@ -102,13 +102,13 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
             long startTime = System.nanoTime();
             for (V1Pod item : list.getItems()) {
                 if (!item.getStatus().getPhase().equals(VALID_PHASE)) {
-                    logger.debug("Invalid pod {} is not in a valid phase {}", item.getMetadata()
+                    LOGGER.debug("Invalid pod {} is not in a valid phase {}", item.getMetadata()
                                                                                   .getName(), item.getStatus()
                                                                                                   .getPhase());
                     continue;
                 }
                 if (item.getStatus().getPodIP().equals(item.getStatus().getHostIP())) {
-                    logger.debug(
+                    LOGGER.debug(
                         "Pod {}.{} is removed because hostIP and podIP are identical ", item.getMetadata()
                                                                                             .getName(),
                         item.getMetadata()
@@ -118,10 +118,10 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                 }
                 ipMap.put(item.getStatus().getPodIP(), createServiceMetaInfo(item.getMetadata()));
             }
-            logger.info("Load {} pods in {}ms", ipMap.size(), (System.nanoTime() - startTime) / 1_000_000);
+            LOGGER.info("Load {} pods in {}ms", ipMap.size(), (System.nanoTime() - startTime) / 1_000_000);
             ipServiceMap.set(ipMap);
         } catch (Throwable th) {
-            logger.error("run load pod error", th);
+            LOGGER.error("run load pod error", th);
         }
     }
 
@@ -231,7 +231,7 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                                                                             .setProtocol(protocol)
                                                                             .setDetectPoint(DetectPoint.server);
 
-                        logger.debug("Transformed ingress->sidecar inbound mesh metric {}", metric);
+                        LOGGER.debug("Transformed ingress->sidecar inbound mesh metric {}", metric);
                         forward(metric);
                     } else {
                         // sidecar -> sidecar(server side)
@@ -254,7 +254,7 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                                                                             .setProtocol(protocol)
                                                                             .setDetectPoint(DetectPoint.server);
 
-                        logger.debug("Transformed sidecar->sidecar(server side) inbound mesh metric {}", metric);
+                        LOGGER.debug("Transformed sidecar->sidecar(server side) inbound mesh metric {}", metric);
                         forward(metric);
                     }
                 } else if (cluster.startsWith("outbound|")) {
@@ -283,7 +283,7 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                                                                         .setProtocol(protocol)
                                                                         .setDetectPoint(DetectPoint.client);
 
-                    logger.debug("Transformed sidecar->sidecar(server side) inbound mesh metric {}", metric);
+                    LOGGER.debug("Transformed sidecar->sidecar(server side) inbound mesh metric {}", metric);
                     forward(metric);
 
                 }
@@ -347,7 +347,7 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                                                                     .setProtocol(protocol)
                                                                     .setDetectPoint(DetectPoint.server);
 
-                logger.debug("Transformed ingress inbound mesh metric {}", metric);
+                LOGGER.debug("Transformed ingress inbound mesh metric {}", metric);
                 forward(metric);
 
                 SocketAddress upstreamRemoteAddressSocketAddress = upstreamRemoteAddress.getSocketAddress();
@@ -378,7 +378,7 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
                                                                             .setProtocol(protocol)
                                                                             .setDetectPoint(DetectPoint.client);
 
-                logger.debug("Transformed ingress outbound mesh metric {}", outboundMetric);
+                LOGGER.debug("Transformed ingress outbound mesh metric {}", outboundMetric);
                 forward(outboundMetric);
             }
         }
@@ -407,13 +407,13 @@ public class K8sALSServiceMeshHTTPAnalysis implements ALSHTTPAnalysis {
     protected ServiceMetaInfo find(String ip, int port) {
         Map<String, ServiceMetaInfo> map = ipServiceMap.get();
         if (map == null) {
-            logger.debug("Unknown ip {}, ip -> service is null", ip);
+            LOGGER.debug("Unknown ip {}, ip -> service is null", ip);
             return ServiceMetaInfo.UNKNOWN;
         }
         if (map.containsKey(ip)) {
             return map.get(ip);
         }
-        logger.debug("Unknown ip {}, ip -> service is {}", ip, map);
+        LOGGER.debug("Unknown ip {}, ip -> service is {}", ip, map);
         return ServiceMetaInfo.UNKNOWN;
     }
 
diff --git a/oap-server/server-receiver-plugin/jaeger-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/jaeger/JaegerGRPCHandler.java b/oap-server/server-receiver-plugin/jaeger-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/jaeger/JaegerGRPCHandler.java
index e537da9..fc05ad3 100644
--- a/oap-server/server-receiver-plugin/jaeger-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/jaeger/JaegerGRPCHandler.java
+++ b/oap-server/server-receiver-plugin/jaeger-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/jaeger/JaegerGRPCHandler.java
@@ -36,7 +36,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class JaegerGRPCHandler extends CollectorServiceGrpc.CollectorServiceImplBase {
-    private static final Logger logger = LoggerFactory.getLogger(JaegerGRPCHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(JaegerGRPCHandler.class);
 
     private SourceReceiver receiver;
     private JaegerReceiverConfig config;
@@ -51,8 +51,8 @@ public class JaegerGRPCHandler extends CollectorServiceGrpc.CollectorServiceImpl
 
         request.getBatch().getSpansList().forEach(span -> {
             try {
-                if (logger.isDebugEnabled()) {
-                    logger.debug(span.toString());
+                if (LOGGER.isDebugEnabled()) {
+                    LOGGER.debug(span.toString());
                 }
 
                 JaegerSpan jaegerSpan = new JaegerSpan();
@@ -97,7 +97,7 @@ public class JaegerGRPCHandler extends CollectorServiceGrpc.CollectorServiceImpl
 
                 receiver.receive(jaegerSpan);
             } catch (Exception e) {
-                logger.error(e.getMessage(), e);
+                LOGGER.error(e.getMessage(), e);
             }
         });
 
diff --git a/oap-server/server-receiver-plugin/skywalking-clr-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/clr/provider/handler/CLRSourceDispatcher.java b/oap-server/server-receiver-plugin/skywalking-clr-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/clr/provider/handler/CLRSourceDispatcher.java
index 50651d3..ed9d7b8 100644
--- a/oap-server/server-receiver-plugin/skywalking-clr-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/clr/provider/handler/CLRSourceDispatcher.java
+++ b/oap-server/server-receiver-plugin/skywalking-clr-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/clr/provider/handler/CLRSourceDispatcher.java
@@ -39,7 +39,7 @@ import org.slf4j.LoggerFactory;
  **/
 public class CLRSourceDispatcher {
 
-    private static final Logger logger = LoggerFactory.getLogger(CLRSourceDispatcher.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(CLRSourceDispatcher.class);
     private final SourceReceiver sourceReceiver;
 
     public CLRSourceDispatcher(ModuleManager moduleManager) {
diff --git a/oap-server/server-receiver-plugin/skywalking-istio-telemetry-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/istio/telemetry/provider/IstioTelemetryGRPCHandler.java b/oap-server/server-receiver-plugin/skywalking-istio-telemetry-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/istio/telemetry/provider/IstioTelemetryGRPCHandler.java
index 4299d26..37e82a4 100644
--- a/oap-server/server-receiver-plugin/skywalking-istio-telemetry-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/istio/telemetry/provider/IstioTelemetryGRPCHandler.java
+++ b/oap-server/server-receiver-plugin/skywalking-istio-telemetry-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/istio/telemetry/provider/IstioTelemetryGRPCHandler.java
@@ -46,7 +46,7 @@ import org.slf4j.LoggerFactory;
  */
 public class IstioTelemetryGRPCHandler extends HandleMetricServiceGrpc.HandleMetricServiceImplBase {
 
-    private static final Logger logger = LoggerFactory.getLogger(IstioTelemetryGRPCHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(IstioTelemetryGRPCHandler.class);
 
     private static final Joiner JOINER = Joiner.on(".");
 
@@ -64,8 +64,8 @@ public class IstioTelemetryGRPCHandler extends HandleMetricServiceGrpc.HandleMet
     @Override
     public void handleMetric(IstioMetricProto.HandleMetricRequest request,
         StreamObserver<ReportProto.ReportResult> responseObserver) {
-        if (logger.isDebugEnabled()) {
-            logger.debug("Received msg {}", request);
+        if (LOGGER.isDebugEnabled()) {
+            LOGGER.debug("Received msg {}", request);
         }
         for (IstioMetricProto.InstanceMsg i : request.getInstancesList()) {
             counter.inc();
@@ -130,7 +130,7 @@ public class IstioTelemetryGRPCHandler extends HandleMetricServiceGrpc.HandleMet
                                                              .setStatus(status)
                                                              .setProtocol(netProtocol)
                                                              .setDetectPoint(detectPoint);
-                logger.debug("Transformed metrics {}", metrics);
+                LOGGER.debug("Transformed metrics {}", metrics);
 
                 TelemetryDataDispatcher.process(metrics);
             } finally {
diff --git a/oap-server/server-receiver-plugin/skywalking-mesh-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/mesh/MeshGRPCHandler.java b/oap-server/server-receiver-plugin/skywalking-mesh-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/mesh/MeshGRPCHandler.java
index eb994a7..2ad26fb 100644
--- a/oap-server/server-receiver-plugin/skywalking-mesh-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/mesh/MeshGRPCHandler.java
+++ b/oap-server/server-receiver-plugin/skywalking-mesh-receiver-plugin/src/main/java/org/apache/skywalking/aop/server/receiver/mesh/MeshGRPCHandler.java
@@ -27,7 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class MeshGRPCHandler extends ServiceMeshMetricServiceGrpc.ServiceMeshMetricServiceImplBase {
-    private static final Logger logger = LoggerFactory.getLogger(MeshGRPCHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(MeshGRPCHandler.class);
 
     public MeshGRPCHandler(ModuleManager moduleManager) {
 
@@ -38,8 +38,8 @@ public class MeshGRPCHandler extends ServiceMeshMetricServiceGrpc.ServiceMeshMet
         return new StreamObserver<ServiceMeshMetric>() {
             @Override
             public void onNext(ServiceMeshMetric metrics) {
-                if (logger.isDebugEnabled()) {
-                    logger.debug("Received mesh metrics: {}", metrics);
+                if (LOGGER.isDebugEnabled()) {
+                    LOGGER.debug("Received mesh metrics: {}", metrics);
                 }
 
                 TelemetryDataDispatcher.process(metrics.toBuilder());
@@ -47,7 +47,7 @@ public class MeshGRPCHandler extends ServiceMeshMetricServiceGrpc.ServiceMeshMet
 
             @Override
             public void onError(Throwable throwable) {
-                logger.error(throwable.getMessage(), throwable);
+                LOGGER.error(throwable.getMessage(), throwable);
                 responseObserver.onCompleted();
             }
 
diff --git a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/analysis/cache/caffeine/CaffeineSpanCache.java b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/analysis/cache/caffeine/CaffeineSpanCache.java
index 41d1574..f5129e3 100644
--- a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/analysis/cache/caffeine/CaffeineSpanCache.java
+++ b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/analysis/cache/caffeine/CaffeineSpanCache.java
@@ -40,7 +40,7 @@ import zipkin2.Span;
  * time, I have to set a timer to write a meaningless trace, for active expire.
  */
 public class CaffeineSpanCache implements ISpanCache, RemovalListener<String, ZipkinTrace> {
-    private static final Logger logger = LoggerFactory.getLogger(CaffeineSpanCache.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(CaffeineSpanCache.class);
     private Cache<String, ZipkinTrace> inProcessSpanCache;
     private ReentrantLock newTraceLock;
 
@@ -67,8 +67,8 @@ public class CaffeineSpanCache implements ISpanCache, RemovalListener<String, Zi
         try {
             Zipkin2SkyWalkingTransfer.INSTANCE.transfer(trace);
         } catch (Exception e) {
-            logger.error(e.getMessage(), e);
-            logger.warn("Zipkin trace:" + trace);
+            LOGGER.error(e.getMessage(), e);
+            LOGGER.warn("Zipkin trace:" + trace);
         }
     }
 
diff --git a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV1JettyHandler.java b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV1JettyHandler.java
index 6ffabb6..7f506dc 100644
--- a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV1JettyHandler.java
+++ b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV1JettyHandler.java
@@ -30,7 +30,7 @@ import org.slf4j.LoggerFactory;
 import zipkin2.codec.SpanBytesDecoder;
 
 public class SpanV1JettyHandler extends JettyHandler {
-    private static final Logger logger = LoggerFactory.getLogger(SpanV1JettyHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(SpanV1JettyHandler.class);
 
     private ZipkinReceiverConfig config;
     private SourceReceiver sourceReceiver;
@@ -64,7 +64,7 @@ public class SpanV1JettyHandler extends JettyHandler {
         } catch (Exception e) {
             response.setStatus(500);
 
-            logger.error(e.getMessage(), e);
+            LOGGER.error(e.getMessage(), e);
         }
     }
 
diff --git a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV2JettyHandler.java b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV2JettyHandler.java
index 05ba040..bc2e6da 100644
--- a/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV2JettyHandler.java
+++ b/oap-server/server-receiver-plugin/zipkin-receiver-plugin/src/main/java/org/apache/skywalking/oap/server/receiver/zipkin/handler/SpanV2JettyHandler.java
@@ -30,7 +30,7 @@ import org.slf4j.LoggerFactory;
 import zipkin2.codec.SpanBytesDecoder;
 
 public class SpanV2JettyHandler extends JettyHandler {
-    private static final Logger logger = LoggerFactory.getLogger(SpanV2JettyHandler.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(SpanV2JettyHandler.class);
 
     private ZipkinReceiverConfig config;
     private SourceReceiver sourceReceiver;
@@ -64,7 +64,7 @@ public class SpanV2JettyHandler extends JettyHandler {
         } catch (Exception e) {
             response.setStatus(500);
 
-            logger.error(e.getMessage(), e);
+            LOGGER.error(e.getMessage(), e);
         }
     }
 }
diff --git a/oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/BatchProcessEsDAO.java b/oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/BatchProcessEsDAO.java
index 842ef6f..3c87620 100644
--- a/oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/BatchProcessEsDAO.java
+++ b/oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/BatchProcessEsDAO.java
@@ -33,7 +33,7 @@ import org.slf4j.LoggerFactory;
 
 public class BatchProcessEsDAO extends EsDAO implements IBatchDAO {
 
-    private static final Logger logger = LoggerFactory.getLogger(BatchProcessEsDAO.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(BatchProcessEsDAO.class);
 
     private BulkProcessor bulkProcessor;
     private final int bulkActions;
diff --git a/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/SQLExecutor.java b/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/SQLExecutor.java
index 90dc963..1e09b51 100644
--- a/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/SQLExecutor.java
+++ b/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/SQLExecutor.java
@@ -32,7 +32,7 @@ import org.slf4j.LoggerFactory;
  */
 public class SQLExecutor implements InsertRequest, UpdateRequest {
 
-    private static final Logger logger = LoggerFactory.getLogger(SQLExecutor.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(SQLExecutor.class);
 
     private String sql;
     private List<Object> param;
@@ -49,7 +49,7 @@ public class SQLExecutor implements InsertRequest, UpdateRequest {
             preparedStatement.setObject(i + 1, param.get(i));
         }
 
-        logger.debug("execute aql in batch: {}", sql);
+        LOGGER.debug("execute aql in batch: {}", sql);
         preparedStatement.execute();
     }
 }
diff --git a/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/h2/dao/H2NetworkAddressAliasDAO.java b/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/h2/dao/H2NetworkAddressAliasDAO.java
index f42bf74..d0e22fe 100755
--- a/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/h2/dao/H2NetworkAddressAliasDAO.java
+++ b/oap-server/server-storage-plugin/storage-jdbc-hikaricp-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/jdbc/h2/dao/H2NetworkAddressAliasDAO.java
@@ -31,7 +31,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class H2NetworkAddressAliasDAO extends H2SQLExecutor implements INetworkAddressAliasDAO {
-    private static final Logger logger = LoggerFactory.getLogger(H2NetworkAddressAliasDAO.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(H2NetworkAddressAliasDAO.class);
     private JDBCHikariCPClient h2Client;
 
     public H2NetworkAddressAliasDAO(JDBCHikariCPClient h2Client) {
@@ -63,7 +63,7 @@ public class H2NetworkAddressAliasDAO extends H2SQLExecutor implements INetworkA
                 throw new IOException(e);
             }
         } catch (Throwable t) {
-            logger.error(t.getMessage(), t);
+            LOGGER.error(t.getMessage(), t);
         }
         return networkAddressAliases;
     }
diff --git a/skywalking-ui b/skywalking-ui
index 60ca1cd..34f98b1 160000
--- a/skywalking-ui
+++ b/skywalking-ui
@@ -1 +1 @@
-Subproject commit 60ca1cd698ba058850779717535b2b7119e95141
+Subproject commit 34f98b1c9aa667cc481abe6bbe46fa361124e1a2
diff --git a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/AbstractRunningGenerator.java b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/AbstractRunningGenerator.java
index 960fb91..1807486 100644
--- a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/AbstractRunningGenerator.java
+++ b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/AbstractRunningGenerator.java
@@ -29,7 +29,7 @@ import org.apache.logging.log4j.Logger;
 import org.apache.skywalking.plugin.test.helper.exception.GenerateFailedException;
 
 public abstract class AbstractRunningGenerator implements ScenarioRunningScriptGenerator {
-    private static final Logger logger = LogManager.getLogger(MethodHandles.lookup().lookupClass());
+    private static final Logger LOGGER = LogManager.getLogger(MethodHandles.lookup().lookupClass());
     protected final Configuration cfg;
 
     protected AbstractRunningGenerator() {
@@ -56,7 +56,7 @@ public abstract class AbstractRunningGenerator implements ScenarioRunningScriptG
             cfg.getTemplate("scenario.sh")
                .process(root, new FileWriter(new File(configuration.outputDir() + File.separator + "scenario.sh")));
         } catch (Exception e) {
-            logger.error("Failed to write scenario.sh", e);
+            LOGGER.error("Failed to write scenario.sh", e);
         }
     }
 
diff --git a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerComposeRunningGenerator.java b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerComposeRunningGenerator.java
index 89483b4..090adb6 100644
--- a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerComposeRunningGenerator.java
+++ b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerComposeRunningGenerator.java
@@ -31,7 +31,7 @@ import java.lang.invoke.MethodHandles;
 import java.util.Map;
 
 public class DockerComposeRunningGenerator extends AbstractRunningGenerator {
-    private static final Logger logger = LogManager.getLogger(MethodHandles.lookup().lookupClass());
+    private static final Logger LOGGER = LogManager.getLogger(MethodHandles.lookup().lookupClass());
 
     protected DockerComposeRunningGenerator() {
     }
@@ -54,7 +54,7 @@ public class DockerComposeRunningGenerator extends AbstractRunningGenerator {
             cfg.getTemplate("docker-compose.template")
                .process(root, new FileWriter(new File(configuration.outputDir(), "docker-compose.yml")));
         } catch (TemplateException | IOException e) {
-            logger.error(e);
+            LOGGER.error(e);
         }
     }
 
@@ -67,7 +67,7 @@ public class DockerComposeRunningGenerator extends AbstractRunningGenerator {
         try {
             cfg.getTemplate("compose-start-script.template").process(root, out);
         } catch (Exception e) {
-            logger.error("Failed to generate running script.", e);
+            LOGGER.error("Failed to generate running script.", e);
         }
         return out.toString();
     }
diff --git a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerContainerRunningGenerator.java b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerContainerRunningGenerator.java
index 1b893a7..f7e923d 100644
--- a/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerContainerRunningGenerator.java
+++ b/test/plugin/runner-helper/src/main/java/org/apache/skywalking/plugin/test/helper/DockerContainerRunningGenerator.java
@@ -25,7 +25,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class DockerContainerRunningGenerator extends AbstractRunningGenerator {
-    private static final Logger logger = LogManager.getLogger(MethodHandles.lookup().lookupClass());
+    private static final Logger LOGGER = LogManager.getLogger(MethodHandles.lookup().lookupClass());
 
     protected DockerContainerRunningGenerator() {
     }
@@ -43,7 +43,7 @@ public class DockerContainerRunningGenerator extends AbstractRunningGenerator {
         try {
             cfg.getTemplate("container-start-script.template").process(root, out);
         } catch (Exception e) {
-            logger.error("Failed to generate running script.", e);
+            LOGGER.error("Failed to generate running script.", e);
         }
         return out.toString();
     }
diff --git a/test/plugin/scenarios/activemq-scenario/src/main/java/org/apache/skywalking/apm/testcase/activemq/controller/CaseController.java b/test/plugin/scenarios/activemq-scenario/src/main/java/org/apache/skywalking/apm/testcase/activemq/controller/CaseController.java
index a4a1545..85a4162 100644
--- a/test/plugin/scenarios/activemq-scenario/src/main/java/org/apache/skywalking/apm/testcase/activemq/controller/CaseController.java
+++ b/test/plugin/scenarios/activemq-scenario/src/main/java/org/apache/skywalking/apm/testcase/activemq/controller/CaseController.java
@@ -39,7 +39,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Value("${activemq.server}")
     private String brokenUrl;
@@ -68,12 +68,12 @@ public class CaseController {
             session.close();
             connection.close();
         } catch (Exception ex) {
-            logger.error(ex);
+            LOGGER.error(ex);
             try {
                 session.close();
                 connection.close();
             } catch (JMSException e) {
-                logger.error(e);
+                LOGGER.error(e);
             }
         }
         new ConsumerThread().start();
@@ -92,12 +92,12 @@ public class CaseController {
             connection.getMetaData().getJMSVersion();
             connection.close();
         } catch (Exception ex) {
-            logger.error(ex);
+            LOGGER.error(ex);
             try {
                 session.close();
                 connection.close();
             } catch (JMSException e) {
-                logger.error(e);
+                LOGGER.error(e);
             }
             return FAIL;
         }
@@ -120,12 +120,12 @@ public class CaseController {
                 session.close();
                 connection.close();
             } catch (Exception ex) {
-                logger.error(ex);
+                LOGGER.error(ex);
                 try {
                     session.close();
                     connection.close();
                 } catch (JMSException e) {
-                    logger.error(e);
+                    LOGGER.error(e);
                 }
             }
         }
diff --git a/test/plugin/scenarios/avro-scenario/avro-client/src/main/java/org/apache/skywalking/apm/testcase/avro/controller/CaseController.java b/test/plugin/scenarios/avro-scenario/avro-client/src/main/java/org/apache/skywalking/apm/testcase/avro/controller/CaseController.java
index be54f66..d51e8a5 100644
--- a/test/plugin/scenarios/avro-scenario/avro-client/src/main/java/org/apache/skywalking/apm/testcase/avro/controller/CaseController.java
+++ b/test/plugin/scenarios/avro-scenario/avro-client/src/main/java/org/apache/skywalking/apm/testcase/avro/controller/CaseController.java
@@ -33,7 +33,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RestController
 @RequestMapping("/case")
 public class CaseController {
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
     private Greeter nettyClient;
diff --git a/test/plugin/scenarios/canal-scenario/src/main/java/org/apache/skywalking/apm/testcase/canal/controller/CaseController.java b/test/plugin/scenarios/canal-scenario/src/main/java/org/apache/skywalking/apm/testcase/canal/controller/CaseController.java
index 4a3f495..317c5c7 100644
--- a/test/plugin/scenarios/canal-scenario/src/main/java/org/apache/skywalking/apm/testcase/canal/controller/CaseController.java
+++ b/test/plugin/scenarios/canal-scenario/src/main/java/org/apache/skywalking/apm/testcase/canal/controller/CaseController.java
@@ -38,7 +38,7 @@ public class CaseController {
 
     private static final String SUCCESS = "Success";
 
-    private Logger logger = LoggerFactory.getLogger(CaseController.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(CaseController.class);
 
     @Value(value = "${canal.host}")
     private String address;
@@ -56,10 +56,10 @@ public class CaseController {
                 connector.rollback();
                 Message message = connector.getWithoutAck(batchSize);
                 long batchId = message.getId();
-                logger.info(message.getEntries().toString());
+                LOGGER.info(message.getEntries().toString());
                 connector.ack(batchId);
             } catch (Exception ex) {
-                logger.error(ex.toString());
+                LOGGER.error(ex.toString());
             }
         });
         return SUCCESS;
diff --git a/test/plugin/scenarios/cassandra-java-driver-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/cassandra/controller/CaseController.java b/test/plugin/scenarios/cassandra-java-driver-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/cassandra/controller/CaseController.java
index 89c0e8c..5a8aef5 100644
--- a/test/plugin/scenarios/cassandra-java-driver-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/cassandra/controller/CaseController.java
+++ b/test/plugin/scenarios/cassandra-java-driver-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/cassandra/controller/CaseController.java
@@ -50,20 +50,20 @@ public class CaseController {
     private static final String DROP_TABLE_SQL = "DROP TABLE IF EXISTS demo.test";
     private static final String DROP_KEYSPACE = "DROP KEYSPACE IF EXISTS demo";
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
     private static final String SUCCESS = "Success";
 
     @RequestMapping("/cassandra")
     @ResponseBody
     public String testcase() {
-        logger.info("cassandra contact points: {}:{}", host, port);
+        LOGGER.info("cassandra contact points: {}:{}", host, port);
 
         Cluster cluster = null;
         Session session = null;
         try {
             cluster = Cluster.builder().addContactPoint(host).withPort(port).withoutJMXReporting().build();
             session = cluster.connect();
-            logger.info("cassandra connection open");
+            LOGGER.info("cassandra connection open");
 
             execute(session);
             executeAsync(session);
@@ -76,73 +76,73 @@ public class CaseController {
             if (cluster != null) {
                 cluster.close();
             }
-            logger.info("cassandra connection close");
+            LOGGER.info("cassandra connection close");
         }
     }
 
     private void execute(Session session) {
-        logger.info("execute in sync");
+        LOGGER.info("execute in sync");
 
         ResultSet createKeyspaceDataResultSet = session.execute(CREATE_KEYSPACE_SQL);
-        logger.info("CREATE KEYSPACE result: " + createKeyspaceDataResultSet.toString());
+        LOGGER.info("CREATE KEYSPACE result: " + createKeyspaceDataResultSet.toString());
 
         ResultSet createTableDataResultSet = session.execute(CREATE_TABLE_SQL);
-        logger.info("CREATE TABLE result: " + createTableDataResultSet.toString());
+        LOGGER.info("CREATE TABLE result: " + createTableDataResultSet.toString());
 
         PreparedStatement insertDataPreparedStatement = session.prepare(INSERT_DATA_SQL);
         ResultSet insertDataResultSet = session.execute(insertDataPreparedStatement.bind("101", "foobar"));
-        logger.info("INSERT result: " + insertDataResultSet.toString());
+        LOGGER.info("INSERT result: " + insertDataResultSet.toString());
 
         PreparedStatement selectDataPreparedStatement = session.prepare(SELECT_DATA_SQL);
         ResultSet resultSet = session.execute(selectDataPreparedStatement.bind("101"));
         Row row = resultSet.one();
-        logger.info("SELECT result: id: {}, value: {}", row.getString("id"), row.getString("value"));
+        LOGGER.info("SELECT result: id: {}, value: {}", row.getString("id"), row.getString("value"));
 
         PreparedStatement deleteDataPreparedStatement = session.prepare(DELETE_DATA_SQL);
         ResultSet deleteDataResultSet = session.execute(deleteDataPreparedStatement.bind("101"));
-        logger.info("DELETE result: " + deleteDataResultSet.toString());
+        LOGGER.info("DELETE result: " + deleteDataResultSet.toString());
 
         ResultSet dropTableDataResultSet = session.execute(DROP_TABLE_SQL);
-        logger.info("DROP TABLE result: " + dropTableDataResultSet.toString());
+        LOGGER.info("DROP TABLE result: " + dropTableDataResultSet.toString());
 
         ResultSet dropKeyspaceDataResultSet = session.execute(DROP_KEYSPACE);
-        logger.info("DROP KEYSPACE result: " + dropKeyspaceDataResultSet.toString());
+        LOGGER.info("DROP KEYSPACE result: " + dropKeyspaceDataResultSet.toString());
     }
 
     private void executeAsync(Session session) {
-        logger.info("execute in async");
+        LOGGER.info("execute in async");
 
         ResultSetFuture createKeyspaceDataResultSetFuture = session.executeAsync(CREATE_KEYSPACE_SQL);
         ResultSet createKeyspaceDataResultSet = createKeyspaceDataResultSetFuture.getUninterruptibly();
-        logger.info("CREATE KEYSPACE result: " + createKeyspaceDataResultSet.toString());
+        LOGGER.info("CREATE KEYSPACE result: " + createKeyspaceDataResultSet.toString());
 
         ResultSetFuture createTableDataResultSetFuture = session.executeAsync(CREATE_TABLE_SQL);
         ResultSet createTableDataResultSet = createTableDataResultSetFuture.getUninterruptibly();
-        logger.info("CREATE TABLE result: " + createTableDataResultSet.toString());
+        LOGGER.info("CREATE TABLE result: " + createTableDataResultSet.toString());
 
         PreparedStatement insertDataPreparedStatement = session.prepare(INSERT_DATA_SQL);
         ResultSetFuture insertDataResultSetFuture = session.executeAsync(insertDataPreparedStatement.bind("101", "foobar"));
         ResultSet insertDataResultSet = insertDataResultSetFuture.getUninterruptibly();
-        logger.info("INSERT result: " + insertDataResultSet.toString());
+        LOGGER.info("INSERT result: " + insertDataResultSet.toString());
 
         PreparedStatement selectDataPreparedStatement = session.prepare(SELECT_DATA_SQL);
         ResultSetFuture resultSetFuture = session.executeAsync(selectDataPreparedStatement.bind("101"));
         ResultSet resultSet = resultSetFuture.getUninterruptibly();
         Row row = resultSet.one();
-        logger.info("SELECT result: id: {}, value: {}", row.getString("id"), row.getString("value"));
+        LOGGER.info("SELECT result: id: {}, value: {}", row.getString("id"), row.getString("value"));
 
         PreparedStatement deleteDataPreparedStatement = session.prepare(DELETE_DATA_SQL);
         ResultSetFuture deleteDataResultSetFuture = session.executeAsync(deleteDataPreparedStatement.bind("101"));
         ResultSet deleteDataResultSet = deleteDataResultSetFuture.getUninterruptibly();
-        logger.info("DELETE result: " + deleteDataResultSet.toString());
+        LOGGER.info("DELETE result: " + deleteDataResultSet.toString());
 
         ResultSetFuture dropTableDataResultSetFuture = session.executeAsync(DROP_TABLE_SQL);
         ResultSet dropTableDataResultSet = dropTableDataResultSetFuture.getUninterruptibly();
-        logger.info("DROP TABLE result: " + dropTableDataResultSet.toString());
+        LOGGER.info("DROP TABLE result: " + dropTableDataResultSet.toString());
 
         ResultSetFuture dropKeyspaceDataResultSetFuture = session.executeAsync(DROP_KEYSPACE);
         ResultSet dropKeyspaceDataResultSet = dropKeyspaceDataResultSetFuture.getUninterruptibly();
-        logger.info("DROP KEYSPACE result: " + dropKeyspaceDataResultSet.toString());
+        LOGGER.info("DROP KEYSPACE result: " + dropKeyspaceDataResultSet.toString());
     }
 
     @RequestMapping("/healthCheck")
@@ -153,10 +153,10 @@ public class CaseController {
         try {
             cluster = Cluster.builder().addContactPoint(host).withPort(port).withoutJMXReporting().build();
             session = cluster.connect();
-            logger.info("cassandra connection open");
+            LOGGER.info("cassandra connection open");
 
             PreparedStatement testPreparedStatement = session.prepare(TEST_EXIST_SQL);
-            logger.info("Test result:" + testPreparedStatement.toString());
+            LOGGER.info("Test result:" + testPreparedStatement.toString());
         } finally {
             if (session != null) {
                 session.close();
@@ -164,7 +164,7 @@ public class CaseController {
             if (cluster != null) {
                 cluster.close();
             }
-            logger.info("cassandra connection close");
+            LOGGER.info("cassandra connection close");
         }
         return SUCCESS;
     }
diff --git a/test/plugin/scenarios/customize-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/customize/controller/CustomizeController.java b/test/plugin/scenarios/customize-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/customize/controller/CustomizeController.java
index 212431c..760243c 100644
--- a/test/plugin/scenarios/customize-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/customize/controller/CustomizeController.java
+++ b/test/plugin/scenarios/customize-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/customize/controller/CustomizeController.java
@@ -34,7 +34,7 @@ import test.org.apache.skywalking.apm.testcase.customize.service.TestService2;
 @RequestMapping("/case")
 public class CustomizeController {
 
-    private Logger logger = LoggerFactory.getLogger(CustomizeController.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(CustomizeController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -78,7 +78,7 @@ public class CustomizeController {
             add("a2");
         }}, 123);
 
-        logger.info(SUCCESS);
+        LOGGER.info(SUCCESS);
         return SUCCESS;
     }
 
diff --git a/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/Application.java b/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/Application.java
index d8d0f9f..119a59f 100644
--- a/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/Application.java
+++ b/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/Application.java
@@ -26,13 +26,13 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 @SpringBootApplication
 public class Application {
 
-    private static final Logger logger = LogManager.getLogger(Application.class);
+    private static final Logger LOGGER = LogManager.getLogger(Application.class);
 
     public static void main(String[] args) {
         try {
             SpringApplication.run(Application.class, args);
         } catch (Exception ex) {
-            logger.error("Application start error", ex);
+            LOGGER.error("Application start error", ex);
             throw ex;
         }
     }
diff --git a/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/job/DemoSimpleJob.java b/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/job/DemoSimpleJob.java
index a22394f..ca85ef5 100644
--- a/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/job/DemoSimpleJob.java
+++ b/test/plugin/scenarios/elasticjob-3.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticjob/job/DemoSimpleJob.java
@@ -35,7 +35,7 @@ import java.util.concurrent.CountDownLatch;
 @Component
 public class DemoSimpleJob implements SimpleJob {
     
-    private final Logger logger = LoggerFactory.getLogger(DemoSimpleJob.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(DemoSimpleJob.class);
     OkHttpClient client = new OkHttpClient.Builder().build();
 
     private CountDownLatch latch = new CountDownLatch(1);
@@ -50,7 +50,7 @@ public class DemoSimpleJob implements SimpleJob {
 
     @Override
     public void execute(ShardingContext shardingContext) {
-        logger.info("Elastic Job Item: {} | Time: {} | Thread: {} | {}",
+        LOGGER.info("Elastic Job Item: {} | Time: {} | Thread: {} | {}",
                 shardingContext.getShardingItem(), new SimpleDateFormat("HH:mm:ss").format(new Date()), Thread.currentThread().getId(), "SIMPLE");
         Request request = new Request.Builder().url("http://localhost:8080/elasticjob-3.x-scenario/case/ping").build();
         Response response = null;
diff --git a/test/plugin/scenarios/elasticsearch-5.x-scenario/src/main/java/test/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java b/test/plugin/scenarios/elasticsearch-5.x-scenario/src/main/java/test/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
index 0c7e04a..71cb3b9 100644
--- a/test/plugin/scenarios/elasticsearch-5.x-scenario/src/main/java/test/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
+++ b/test/plugin/scenarios/elasticsearch-5.x-scenario/src/main/java/test/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
@@ -40,7 +40,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Value("${elasticsearch.server}")
     private String host;
@@ -51,7 +51,7 @@ public class CaseController {
         ClusterHealthResponse response = client.admin().cluster().prepareHealth().setWaitForYellowStatus().get();
         if (response.isTimedOut()) {
             String message = "elastic search node start fail!";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
         client.close();
@@ -94,7 +94,7 @@ public class CaseController {
                                             .endObject())
                   .get();
         } catch (IOException e) {
-            logger.error("index document error.", e);
+            LOGGER.error("index document error.", e);
             throw e;
         }
     }
@@ -109,7 +109,7 @@ public class CaseController {
                   .setDoc(XContentFactory.jsonBuilder().startObject().field("price", "9.9").endObject())
                   .execute();
         } catch (IOException e) {
-            logger.error("update document error.", e);
+            LOGGER.error("update document error.", e);
             throw e;
         }
     }
@@ -133,7 +133,7 @@ public class CaseController {
             client = new PreBuiltTransportClient(settings).addTransportAddress(new InetSocketTransportAddress(InetAddress
                 .getByName(host), 9300));
         } catch (UnknownHostException e) {
-            logger.error("create client error", e);
+            LOGGER.error("create client error", e);
             throw e;
         }
         return client;
diff --git a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/RestHighLevelClientCase.java b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/RestHighLevelClientCase.java
index 008261b..5d2ee41 100644
--- a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/RestHighLevelClientCase.java
+++ b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/RestHighLevelClientCase.java
@@ -58,7 +58,7 @@ import static java.util.Collections.singletonMap;
 @Component
 public class RestHighLevelClientCase {
 
-    private static Logger logger = LogManager.getLogger(RestHighLevelClientCase.class);
+    private static final Logger LOGGER = LogManager.getLogger(RestHighLevelClientCase.class);
 
     @Autowired
     private RestHighLevelClient client;
@@ -71,7 +71,7 @@ public class RestHighLevelClientCase {
         ClusterHealthResponse response = client.cluster().health(request, RequestOptions.DEFAULT);
         if (response.isTimedOut()) {
             String message = "elastic search node start fail!";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
         return true;
@@ -132,7 +132,7 @@ public class RestHighLevelClientCase {
         CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);
         if (createIndexResponse.isAcknowledged() == false) {
             String message = "elasticsearch create index fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -150,7 +150,7 @@ public class RestHighLevelClientCase {
         IndexResponse indexResponse = client.index(indexRequest, RequestOptions.DEFAULT);
         if (indexResponse.status().getStatus() >= 400) {
             String message = "elasticsearch index data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -161,7 +161,7 @@ public class RestHighLevelClientCase {
 
         if (!getResponse.isExists()) {
             String message = "elasticsearch get data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -175,7 +175,7 @@ public class RestHighLevelClientCase {
         UpdateResponse updateResponse = client.update(request, RequestOptions.DEFAULT);
         if (updateResponse.getVersion() != 2) {
             String message = "elasticsearch update data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -185,7 +185,7 @@ public class RestHighLevelClientCase {
         AcknowledgedResponse deleteIndexResponse = client.indices().delete(request, RequestOptions.DEFAULT);
         if (!deleteIndexResponse.isAcknowledged()) {
             String message = "elasticsearch delete index fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -203,7 +203,7 @@ public class RestHighLevelClientCase {
         SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
         if (!(searchResponse.getHits().totalHits > 0)) {
             String message = "elasticsearch search data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
diff --git a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/TransportClientCase.java b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/TransportClientCase.java
index 9e2e6b5..4878c33 100644
--- a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/TransportClientCase.java
+++ b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/TransportClientCase.java
@@ -32,7 +32,7 @@ import java.util.UUID;
 @Component
 public class TransportClientCase {
 
-    private static Logger logger = LogManager.getLogger(TransportClientCase.class);
+    private static final Logger LOGGER = LogManager.getLogger(TransportClientCase.class);
 
     @Autowired
     private TransportClient client;
@@ -71,7 +71,7 @@ public class TransportClientCase {
                     .endObject())
                 .get();
         } catch (IOException e) {
-            logger.error("index document error.", e);
+            LOGGER.error("index document error.", e);
             throw e;
         }
     }
@@ -86,7 +86,7 @@ public class TransportClientCase {
                 .setDoc(XContentFactory.jsonBuilder().startObject().field("price", "9.9").endObject())
                 .execute();
         } catch (IOException e) {
-            logger.error("update document error.", e);
+            LOGGER.error("update document error.", e);
             throw e;
         }
     }
diff --git a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
index e3928c7..a93623b 100644
--- a/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
+++ b/test/plugin/scenarios/elasticsearch-6.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
@@ -31,7 +31,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/elasticsearch-case/case")
 public class CaseController {
 
-    private static Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Autowired
     private RestHighLevelClientCase restHighLevelClientCase;
diff --git a/test/plugin/scenarios/elasticsearch-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java b/test/plugin/scenarios/elasticsearch-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
index ef71b71..9f2aa19 100644
--- a/test/plugin/scenarios/elasticsearch-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
+++ b/test/plugin/scenarios/elasticsearch-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/elasticsearch/controller/CaseController.java
@@ -66,7 +66,7 @@ import static java.util.Collections.singletonMap;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Autowired
     private RestHighLevelClient client;
@@ -80,7 +80,7 @@ public class CaseController {
         ClusterHealthResponse response = client.cluster().health(request, RequestOptions.DEFAULT);
         if (response.isTimedOut()) {
             String message = "elastic search node start fail!";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
         return "Success";
@@ -131,7 +131,7 @@ public class CaseController {
         ClusterHealthResponse response = client.cluster().health(request, RequestOptions.DEFAULT);
         if (response.isTimedOut()) {
             String message = "elastic search health fail!";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -148,7 +148,7 @@ public class CaseController {
         ClusterUpdateSettingsResponse response = client.cluster().putSettings(request, RequestOptions.DEFAULT);
         if (response == null) {
             String message = "elasticsearch put settings fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -157,7 +157,7 @@ public class CaseController {
         ClusterGetSettingsResponse response = client.cluster().getSettings(new ClusterGetSettingsRequest(), RequestOptions.DEFAULT);
         if (response == null) {
             String message = "elasticsearch get settings fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -191,7 +191,7 @@ public class CaseController {
         CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT);
         if (createIndexResponse.isAcknowledged() == false) {
             String message = "elasticsearch create index fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -209,7 +209,7 @@ public class CaseController {
         IndexResponse indexResponse = client.index(indexRequest, RequestOptions.DEFAULT);
         if (indexResponse.status().getStatus() >= 400) {
             String message = "elasticsearch index data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -220,7 +220,7 @@ public class CaseController {
 
         if (!getResponse.isExists()) {
             String message = "elasticsearch get data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -234,7 +234,7 @@ public class CaseController {
         UpdateResponse updateResponse = client.update(request, RequestOptions.DEFAULT);
         if (updateResponse.getVersion() != 2) {
             String message = "elasticsearch update data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -244,7 +244,7 @@ public class CaseController {
         AcknowledgedResponse deleteIndexResponse = client.indices().delete(request, RequestOptions.DEFAULT);
         if (!deleteIndexResponse.isAcknowledged()) {
             String message = "elasticsearch delete index fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
@@ -263,7 +263,7 @@ public class CaseController {
         int length = searchResponse.getHits().getHits().length;
         if (!(length > 0)) {
             String message = "elasticsearch search data fail.";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         }
     }
diff --git a/test/plugin/scenarios/feign-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java b/test/plugin/scenarios/feign-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
index 82d2b37..551a7f2 100644
--- a/test/plugin/scenarios/feign-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
+++ b/test/plugin/scenarios/feign-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
@@ -29,7 +29,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @RequestMapping("/case")
 public class CaseController {
 
-    private Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @ResponseBody
     @RequestMapping("/healthCheck")
@@ -43,7 +43,7 @@ public class CaseController {
         RestRequest request = RestRequest.connect();
         request.createUser(1, "test");
         User user = request.getById(1);
-        logger.info("find Id{} user. User name is {} ", user.getId(), user.getUserName());
+        LOGGER.info("find Id{} user. User name is {} ", user.getId(), user.getUserName());
         request.updateUser(1, "testA");
         request.modifyUser(1, "testA");
         request.deleteUser(1);
diff --git a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/consumr/ConsumerInterceptor.java b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/consumr/ConsumerInterceptor.java
index 58851a2..5470e7c 100644
--- a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/consumr/ConsumerInterceptor.java
+++ b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/consumr/ConsumerInterceptor.java
@@ -33,18 +33,18 @@ import org.apache.logging.log4j.Logger;
 
 public class ConsumerInterceptor implements ClientInterceptor {
 
-    private Logger logger = LogManager.getLogger(ConsumerInterceptor.class);
+    private static final Logger LOGGER = LogManager.getLogger(ConsumerInterceptor.class);
 
     @Override
     public <ReqT, RespT> ClientCall<ReqT, RespT> interceptCall(MethodDescriptor<ReqT, RespT> descriptor,
         CallOptions options, Channel channel) {
-        logger.info("start interceptor!");
-        logger.info("method type: {}", descriptor.getType());
+        LOGGER.info("start interceptor!");
+        LOGGER.info("method type: {}", descriptor.getType());
         return new ForwardingClientCall.SimpleForwardingClientCall<ReqT, RespT>(channel.newCall(descriptor, options)) {
             @Override
             public void start(Listener<RespT> responseListener, Metadata headers) {
-                logger.info("Peer: {}", channel.authority());
-                logger.info("Operation Name : {}", descriptor.getFullMethodName());
+                LOGGER.info("Peer: {}", channel.authority());
+                LOGGER.info("Operation Name : {}", descriptor.getFullMethodName());
                 Interceptor<RespT> tracingResponseListener = new Interceptor(responseListener);
                 tracingResponseListener.contextSnapshot = "contextSnapshot";
                 delegate().start(tracingResponseListener, headers);
@@ -52,26 +52,26 @@ public class ConsumerInterceptor implements ClientInterceptor {
 
             @Override
             public void cancel(@Nullable String message, @Nullable Throwable cause) {
-                logger.info("cancel");
+                LOGGER.info("cancel");
                 super.cancel(message, cause);
             }
 
             @Override
             public void halfClose() {
-                logger.info("halfClose");
+                LOGGER.info("halfClose");
                 super.halfClose();
             }
 
             @Override
             public void sendMessage(ReqT message) {
-                logger.info("sendMessage ....");
+                LOGGER.info("sendMessage ....");
                 super.sendMessage(message);
             }
         };
     }
 
     private static class Interceptor<RespT> extends ForwardingClientCallListener.SimpleForwardingClientCallListener<RespT> {
-        private Logger logger = LogManager.getLogger(Interceptor.class);
+        private static final Logger LOGGER = LogManager.getLogger(Interceptor.class);
 
         private Object contextSnapshot;
 
@@ -81,28 +81,28 @@ public class ConsumerInterceptor implements ClientInterceptor {
 
         @Override
         public void onHeaders(Metadata headers) {
-            logger.info("on Headers");
+            LOGGER.info("on Headers");
             for (String key : headers.keys()) {
-                logger.info("Receive key: {}", key);
+                LOGGER.info("Receive key: {}", key);
             }
             delegate().onHeaders(headers);
         }
 
         @Override
         public void onMessage(RespT message) {
-            logger.info("contextSnapshot: {}", contextSnapshot);
+            LOGGER.info("contextSnapshot: {}", contextSnapshot);
             delegate().onMessage(message);
         }
 
         @Override
         public void onClose(Status status, Metadata trailers) {
-            logger.info("on close");
+            LOGGER.info("on close");
             delegate().onClose(status, trailers);
         }
 
         @Override
         public void onReady() {
-            logger.info("on Ready");
+            LOGGER.info("on Ready");
             super.onReady();
         }
     }
diff --git a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/controller/CaseController.java b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/controller/CaseController.java
index d0a3a60..f266de4 100644
--- a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/controller/CaseController.java
+++ b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/controller/CaseController.java
@@ -39,7 +39,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -105,16 +105,16 @@ public class CaseController {
 
             @Override
             public void onNext(HelloReply reply) {
-                logger.info("Receive an message from provider. message: {}", reply.getMessage());
+                LOGGER.info("Receive an message from provider. message: {}", reply.getMessage());
                 requestStream.request(1);
             }
 
             public void onError(Throwable throwable) {
-                logger.error("Failed to send data", throwable);
+                LOGGER.error("Failed to send data", throwable);
             }
 
             public void onCompleted() {
-                logger.info("All Done");
+                LOGGER.info("All Done");
             }
         };
 
diff --git a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/interceptor/ProviderInterceptor.java b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/interceptor/ProviderInterceptor.java
index 8559c4c..66090da 100644
--- a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/interceptor/ProviderInterceptor.java
+++ b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/interceptor/ProviderInterceptor.java
@@ -30,25 +30,25 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class ProviderInterceptor implements ServerInterceptor {
-    private Logger logger = LogManager.getLogger(ProviderInterceptor.class);
+    private static final Logger LOGGER = LogManager.getLogger(ProviderInterceptor.class);
 
     @Override
     public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(ServerCall<ReqT, RespT> call, Metadata metadata,
         ServerCallHandler<ReqT, RespT> handler) {
         Map<String, String> headerMap = new HashMap<String, String>();
         for (String key : metadata.keys()) {
-            logger.info("Receive key: {}", key);
+            LOGGER.info("Receive key: {}", key);
             if (!key.endsWith(Metadata.BINARY_HEADER_SUFFIX)) {
                 String value = metadata.get(Metadata.Key.of(key, Metadata.ASCII_STRING_MARSHALLER));
 
                 headerMap.put(key, value);
             }
         }
-        logger.info("authority : {}", call.getAuthority());
+        LOGGER.info("authority : {}", call.getAuthority());
         return new ForwardingServerCallListener.SimpleForwardingServerCallListener<ReqT>(handler.startCall(new ForwardingServerCall.SimpleForwardingServerCall<ReqT, RespT>(call) {
             @Override
             public void sendHeaders(Metadata responseHeaders) {
-                logger.info("sendHeaders....");
+                LOGGER.info("sendHeaders....");
                 Metadata.Key<String> headerKey = Metadata.Key.of("test-server", Metadata.ASCII_STRING_MARSHALLER);
                 responseHeaders.put(headerKey, "test-server");
                 delegate().sendHeaders(responseHeaders);
@@ -62,31 +62,31 @@ public class ProviderInterceptor implements ServerInterceptor {
         }, metadata)) {
             @Override
             public void onReady() {
-                logger.info("onReady....");
+                LOGGER.info("onReady....");
                 delegate().onReady();
             }
 
             @Override
             public void onCancel() {
-                logger.info("onCancel....");
+                LOGGER.info("onCancel....");
                 delegate().onCancel();
             }
 
             @Override
             public void onComplete() {
-                logger.info("onComplete....");
+                LOGGER.info("onComplete....");
                 delegate().onComplete();
             }
 
             @Override
             public void onHalfClose() {
-                logger.info("onHalfClose....");
+                LOGGER.info("onHalfClose....");
                 delegate().onHalfClose();
             }
 
             @Override
             public void onMessage(ReqT message) {
-                logger.info("onMessage....");
+                LOGGER.info("onMessage....");
                 delegate().onMessage(message);
             }
         };
diff --git a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/service/GreeterServiceImpl.java b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/service/GreeterServiceImpl.java
index ee021af..5235d09 100644
--- a/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/service/GreeterServiceImpl.java
+++ b/test/plugin/scenarios/grpc-scenario/src/main/java/org/apache/skywalking/apm/testcase/grpc/provider/service/GreeterServiceImpl.java
@@ -27,14 +27,14 @@ import org.apache.skywalking.apm.testcase.grpc.proto.HelloRequest;
 
 public class GreeterServiceImpl extends GreeterGrpc.GreeterImplBase {
 
-    private Logger logger = LogManager.getLogger(GreeterServiceImpl.class);
+    private static final Logger LOGGER = LogManager.getLogger(GreeterServiceImpl.class);
 
     @Override
     public StreamObserver<HelloRequest> sayHello(final StreamObserver<HelloReply> responseObserver) {
         StreamObserver<HelloRequest> requestStreamObserver = new StreamObserver<HelloRequest>() {
 
             public void onNext(HelloRequest request) {
-                logger.info("Receive an message from client. Message: {}", request.getName());
+                LOGGER.info("Receive an message from client. Message: {}", request.getName());
                 responseObserver.onNext(HelloReply.newBuilder().setMessage("Hi," + request.getName()).build());
             }
 
@@ -43,7 +43,7 @@ public class GreeterServiceImpl extends GreeterGrpc.GreeterImplBase {
             }
 
             public void onCompleted() {
-                logger.info("End the stream.");
+                LOGGER.info("End the stream.");
                 responseObserver.onCompleted();
             }
         };
diff --git a/test/plugin/scenarios/httpasyncclient-scenario/src/main/java/org/apache/skywalking/testcase/httpasyncclient/FrontController.java b/test/plugin/scenarios/httpasyncclient-scenario/src/main/java/org/apache/skywalking/testcase/httpasyncclient/FrontController.java
index f04c212..bfb056c 100644
--- a/test/plugin/scenarios/httpasyncclient-scenario/src/main/java/org/apache/skywalking/testcase/httpasyncclient/FrontController.java
+++ b/test/plugin/scenarios/httpasyncclient-scenario/src/main/java/org/apache/skywalking/testcase/httpasyncclient/FrontController.java
@@ -40,7 +40,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/httpasyncclient/case")
 public class FrontController {
 
-    private static Logger logger = LogManager.getLogger(FrontController.class);
+    private static final Logger LOGGER = LogManager.getLogger(FrontController.class);
 
     @GetMapping("/healthcheck")
     public String healthcheck() {
@@ -85,20 +85,20 @@ public class FrontController {
 
         httpclient.execute(producer3, consumer3, new FutureCallback<HttpResponse>() {
             public void completed(final HttpResponse response3) {
-                logger.info(request3.getRequestLine() + "->" + response3.getStatusLine());
+                LOGGER.info(request3.getRequestLine() + "->" + response3.getStatusLine());
                 try {
                     httpclient.close();
                 } catch (IOException e) {
-                    logger.error("Httpclient  close failed" + e);
+                    LOGGER.error("Httpclient  close failed" + e);
                 }
             }
 
             public void failed(final Exception ex) {
-                logger.error(request3.getRequestLine() + "->" + ex);
+                LOGGER.error(request3.getRequestLine() + "->" + ex);
             }
 
             public void cancelled() {
-                logger.error(request3.getRequestLine() + " cancelled");
+                LOGGER.error(request3.getRequestLine() + " cancelled");
             }
 
         });
diff --git a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/CaseController.java b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/CaseController.java
index 2ae74e1..b509a12 100644
--- a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/CaseController.java
+++ b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/CaseController.java
@@ -37,7 +37,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -46,31 +46,31 @@ public class CaseController {
         HystrixPlugins.getInstance().registerCommandExecutionHook(new HystrixCommandExecutionHook() {
             @Override
             public <T> void onStart(HystrixInvokable<T> commandInstance) {
-                logger.info("[hookA] onStart: " + Thread.currentThread().getId());
+                LOGGER.info("[hookA] onStart: " + Thread.currentThread().getId());
                 super.onStart(commandInstance);
             }
 
             @Override
             public <T> void onExecutionStart(HystrixInvokable<T> commandInstance) {
-                logger.info("[hookA] onExecutionStart: " + Thread.currentThread().getId());
+                LOGGER.info("[hookA] onExecutionStart: " + Thread.currentThread().getId());
                 super.onExecutionStart(commandInstance);
             }
 
             @Override
             public <T> void onExecutionSuccess(HystrixInvokable<T> commandInstance) {
-                logger.info("[hookA] onExecutionSuccess: " + Thread.currentThread().getId());
+                LOGGER.info("[hookA] onExecutionSuccess: " + Thread.currentThread().getId());
                 super.onExecutionSuccess(commandInstance);
             }
 
             @Override
             public <T> Exception onExecutionError(HystrixInvokable<T> commandInstance, Exception e) {
-                logger.info("[hookA] onExecutionError: " + Thread.currentThread().getId());
+                LOGGER.info("[hookA] onExecutionError: " + Thread.currentThread().getId());
                 return super.onExecutionError(commandInstance, e);
             }
 
             @Override
             public <T> Exception onRunError(HystrixCommand<T> commandInstance, Exception e) {
-                logger.info("[hookA] onRunError: " + Thread.currentThread().getId());
+                LOGGER.info("[hookA] onRunError: " + Thread.currentThread().getId());
                 return super.onRunError(commandInstance, e);
             }
         });
@@ -81,9 +81,9 @@ public class CaseController {
     public String testcase() throws InterruptedException, ExecutionException {
         List<Future<String>> fs = new ArrayList<Future<String>>();
         fs.add(new TestBCommand("World").queue());
-        logger.info(new TestACommand("World").execute());
+        LOGGER.info(new TestACommand("World").execute());
         for (Future<String> f : fs) {
-            logger.info(f.get());
+            LOGGER.info(f.get());
         }
         return SUCCESS;
     }
diff --git a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestACommand.java b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestACommand.java
index 8efab6c..a2c3698 100644
--- a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestACommand.java
+++ b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestACommand.java
@@ -24,7 +24,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class TestACommand extends HystrixCommand<String> {
-    private Logger logger = LogManager.getLogger(TestACommand.class);
+    private static final Logger LOGGER = LogManager.getLogger(TestACommand.class);
 
     private String name;
 
@@ -39,20 +39,20 @@ public class TestACommand extends HystrixCommand<String> {
     protected String run() throws Exception {
         Thread.sleep(2001);
         try {
-            logger.info("start run: " + +Thread.currentThread().getId());
+            LOGGER.info("start run: " + +Thread.currentThread().getId());
             return "Hello " + name + "!";
         } finally {
-            logger.info("start end");
+            LOGGER.info("start end");
         }
     }
 
     @Override
     protected String getFallback() {
         try {
-            logger.info("getFallback run: " + Thread.currentThread().getId());
+            LOGGER.info("getFallback run: " + Thread.currentThread().getId());
             return "failed";
         } finally {
-            logger.info("getFallback end");
+            LOGGER.info("getFallback end");
         }
     }
 }
diff --git a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestBCommand.java b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestBCommand.java
index a59f93a..36762f8 100644
--- a/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestBCommand.java
+++ b/test/plugin/scenarios/hystrix-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/hystrix/controller/TestBCommand.java
@@ -25,7 +25,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class TestBCommand extends HystrixCommand<String> {
-    private Logger logger = LogManager.getLogger(TestACommand.class);
+    private static final Logger LOGGER = LogManager.getLogger(TestACommand.class);
 
     private String name;
 
@@ -41,20 +41,20 @@ public class TestBCommand extends HystrixCommand<String> {
     @Override
     protected String run() throws Exception {
         try {
-            logger.info("start run: " + Thread.currentThread().getId());
+            LOGGER.info("start run: " + Thread.currentThread().getId());
             return "Hello " + name + "!";
         } finally {
-            logger.info("start end");
+            LOGGER.info("start end");
         }
     }
 
     @Override
     protected String getFallback() {
         try {
-            logger.info("getFallback run: " + Thread.currentThread().getId());
+            LOGGER.info("getFallback run: " + Thread.currentThread().getId());
             return "failed";
         } finally {
-            logger.info("getFallback end");
+            LOGGER.info("getFallback end");
         }
     }
 }
diff --git a/test/plugin/scenarios/jdk-http-scenario/src/main/java/org/apache/skywalking/apm/testcase/jdkhttp/controller/CaseController.java b/test/plugin/scenarios/jdk-http-scenario/src/main/java/org/apache/skywalking/apm/testcase/jdkhttp/controller/CaseController.java
index 4ff00b6..8310a16 100644
--- a/test/plugin/scenarios/jdk-http-scenario/src/main/java/org/apache/skywalking/apm/testcase/jdkhttp/controller/CaseController.java
+++ b/test/plugin/scenarios/jdk-http-scenario/src/main/java/org/apache/skywalking/apm/testcase/jdkhttp/controller/CaseController.java
@@ -31,7 +31,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
diff --git a/test/plugin/scenarios/kafka-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/kafka/controller/CaseController.java b/test/plugin/scenarios/kafka-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/kafka/controller/CaseController.java
index 1a7258f..8f30787 100644
--- a/test/plugin/scenarios/kafka-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/kafka/controller/CaseController.java
+++ b/test/plugin/scenarios/kafka-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/kafka/controller/CaseController.java
@@ -53,7 +53,7 @@ import static java.util.Objects.isNull;
 @PropertySource("classpath:application.properties")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -83,14 +83,14 @@ public class CaseController {
             producer.send(record, new Callback() {
                 @Override
                 public void onCompletion(RecordMetadata metadata, Exception exception) {
-                    logger.info("send success metadata={}", metadata);
+                    LOGGER.info("send success metadata={}", metadata);
                 }
             });
 
             ProducerRecord<String, String> record2 = new ProducerRecord<String, String>(topicName2, "testKey", Integer.toString(1));
             record2.headers().add("TEST", "TEST".getBytes());
             Callback callback2 = (metadata, exception) -> {
-                logger.info("send success metadata={}", metadata);
+                LOGGER.info("send success metadata={}", metadata);
             };
             producer.send(record2, callback2);
         }, bootstrapServers);
@@ -172,7 +172,7 @@ public class CaseController {
                         producer.send(record, callback);
                     }, bootstrapServers);
                 } catch (Exception e) {
-                    logger.error("check " + bootstrapServers + " " + e.getMessage(), e);
+                    LOGGER.error("check " + bootstrapServers + " " + e.getMessage(), e);
                 }
                 try {
                     Thread.sleep(5000);
@@ -207,12 +207,12 @@ public class CaseController {
 
                 if (!records.isEmpty()) {
                     for (ConsumerRecord<String, String> record : records) {
-                        logger.info("header: {}", new String(record.headers()
+                        LOGGER.info("header: {}", new String(record.headers()
                                                                    .headers("TEST")
                                                                    .iterator()
                                                                    .next()
                                                                    .value()));
-                        logger.info("offset = {}, key = {}, value = {}", record.offset(), record.key(), record.value());
+                        LOGGER.info("offset = {}, key = {}, value = {}", record.offset(), record.key(), record.value());
                     }
                     break;
                 }
diff --git a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/Application.java b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/Application.java
index 2c71b3b..ad8ed13 100644
--- a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/Application.java
+++ b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/Application.java
@@ -26,13 +26,13 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 @SpringBootApplication
 public class Application {
 
-    private static final Logger logger = LogManager.getLogger(Application.class);
+    private static final Logger LOGGER = LogManager.getLogger(Application.class);
 
     public static void main(String[] args) {
         try {
             SpringApplication.run(Application.class, args);
         } catch (Exception ex) {
-            logger.error("Application start error", ex);
+            LOGGER.error("Application start error", ex);
             throw ex;
         }
     }
diff --git a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/MariadbConfig.java b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/MariadbConfig.java
index d4e873b..83afc73 100644
--- a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/MariadbConfig.java
+++ b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/MariadbConfig.java
@@ -25,7 +25,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class MariadbConfig {
-    private static Logger logger = LogManager.getLogger(MariadbConfig.class);
+    private static final Logger LOGGER = LogManager.getLogger(MariadbConfig.class);
     private static String url;
     private static String userName;
     private static String password;
@@ -36,7 +36,7 @@ public class MariadbConfig {
         try {
             properties.load(inputStream);
         } catch (IOException e) {
-            logger.error("Failed to load config", e);
+            LOGGER.error("Failed to load config", e);
         }
 
         url = properties.getProperty("mariadb.url");
diff --git a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/SQLExecutor.java b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/SQLExecutor.java
index e56b33f..74b7ffb 100644
--- a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/SQLExecutor.java
+++ b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/SQLExecutor.java
@@ -27,14 +27,14 @@ import java.sql.SQLException;
 import java.sql.Statement;
 
 public class SQLExecutor implements AutoCloseable {
-    private static Logger logger = LogManager.getLogger(SQLExecutor.class);
+    private static final Logger LOGGER = LogManager.getLogger(SQLExecutor.class);
     private Connection connection;
 
     public SQLExecutor() throws SQLException {
         try {
             Class.forName("org.mariadb.jdbc.Driver");
         } catch (ClassNotFoundException ex) {
-            logger.error(ex);
+            LOGGER.error(ex);
         }
         connection = DriverManager.getConnection(MariadbConfig.getUrl(), MariadbConfig.getUserName(), MariadbConfig.getPassword());
     }
diff --git a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/controller/CaseController.java b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/controller/CaseController.java
index 72136c5..1a39465 100644
--- a/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/controller/CaseController.java
+++ b/test/plugin/scenarios/mariadb-scenario/src/main/java/org/apache/skywalking/apm/testcase/mariadb/controller/CaseController.java
@@ -31,7 +31,7 @@ import java.sql.SQLException;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -50,7 +50,7 @@ public class CaseController {
             sqlExecute.queryData(QUERY_DATA_SQL, "1");
             sqlExecute.execute(DROP_TABLE_SQL);
         } catch (Exception ex) {
-            logger.error("Failed to execute sql.", ex);
+            LOGGER.error("Failed to execute sql.", ex);
             throw ex;
         }
         return SUCCESS;
diff --git a/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/MysqlConfig.java b/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/MysqlConfig.java
index 6e9103c..aa3ad88 100644
--- a/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/MysqlConfig.java
+++ b/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/MysqlConfig.java
@@ -25,7 +25,7 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 public class MysqlConfig {
-    private static Logger logger = LogManager.getLogger(MysqlConfig.class);
+    private static final Logger LOGGER = LogManager.getLogger(MysqlConfig.class);
     private static String url;
     private static String userName;
     private static String password;
@@ -36,7 +36,7 @@ public class MysqlConfig {
         try {
             properties.load(inputStream);
         } catch (IOException e) {
-            logger.error("Failed to load config", e);
+            LOGGER.error("Failed to load config", e);
         }
 
         url = properties.getProperty("mysql.url");
diff --git a/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/controller/CaseController.java b/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/controller/CaseController.java
index 415c654..1cae40e 100644
--- a/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/controller/CaseController.java
+++ b/test/plugin/scenarios/mysql-scenario/src/main/java/org/apache/skywalking/apm/testcase/mysql/controller/CaseController.java
@@ -31,7 +31,7 @@ import java.sql.SQLException;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -55,7 +55,7 @@ public class CaseController {
             sqlExecute.callProcedure(CALL_PROCEDURE_SQL, "nihao");
             sqlExecute.dropProcedure(DROP_PROCEDURE_SQL);
         } catch (Exception e) {
-            logger.error("Failed to execute sql.", e);
+            LOGGER.error("Failed to execute sql.", e);
             throw e;
         }
         return SUCCESS;
diff --git a/test/plugin/scenarios/oracle-scenario/src/main/java/org/apache/skywalking/apm/testcase/oracle/controller/CaseController.java b/test/plugin/scenarios/oracle-scenario/src/main/java/org/apache/skywalking/apm/testcase/oracle/controller/CaseController.java
index bf9d326..c3bb2d2 100644
--- a/test/plugin/scenarios/oracle-scenario/src/main/java/org/apache/skywalking/apm/testcase/oracle/controller/CaseController.java
+++ b/test/plugin/scenarios/oracle-scenario/src/main/java/org/apache/skywalking/apm/testcase/oracle/controller/CaseController.java
@@ -36,7 +36,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Value("${oracle.address}")
     private String oracleHostAndPort;
@@ -85,7 +85,7 @@ public class CaseController {
             queryDataPreparedStatement.setString(1, "1");
             ResultSet resultSet = queryDataPreparedStatement.executeQuery();
             resultSet.next();
-            logger.info("Query id[{}]: value={}", "1", resultSet.getString(2));
+            LOGGER.info("Query id[{}]: value={}", "1", resultSet.getString(2));
             queryDataPreparedStatement.close();
 
             // drop table by using statement
@@ -94,7 +94,7 @@ public class CaseController {
             dropTableStatement.close();
         } catch (SQLException e) {
             String message = "Failed to execute sql";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         } finally {
             if (connection != null) {
@@ -102,7 +102,7 @@ public class CaseController {
                     connection.close();
                 } catch (SQLException e) {
                     String message = "Failed to close connection";
-                    logger.error(message);
+                    LOGGER.error(message);
                     throw new RuntimeException(message);
                 }
             }
@@ -121,7 +121,7 @@ public class CaseController {
             preparedStatement.close();
         } catch (SQLException e) {
             String message = "Failed to execute sql";
-            logger.error(message);
+            LOGGER.error(message);
             throw new RuntimeException(message);
         } finally {
             if (connection != null) {
@@ -129,7 +129,7 @@ public class CaseController {
                     connection.close();
                 } catch (SQLException e) {
                     String message = "Failed to close connection";
-                    logger.error(message);
+                    LOGGER.error(message);
                     throw new RuntimeException(message);
                 }
             }
diff --git a/test/plugin/scenarios/postgresql-above9.4.1207-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java b/test/plugin/scenarios/postgresql-above9.4.1207-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
index 60e1f48..393299d 100644
--- a/test/plugin/scenarios/postgresql-above9.4.1207-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
+++ b/test/plugin/scenarios/postgresql-above9.4.1207-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
@@ -30,7 +30,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/postgresql-scenario/case")
 public class CaseController {
 
-    private static Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Autowired
     PostgresqlConfig postgresqlConfig;
@@ -42,14 +42,14 @@ public class CaseController {
             sqlExecute = new SQLExecutor(postgresqlConfig);
             sqlExecute.checkPG(ConstSql.TEST_SQL);
         } catch (SQLException e) {
-            logger.error("Failed to execute sql.", e);
+            LOGGER.error("Failed to execute sql.", e);
             throw e;
         } finally {
             if (sqlExecute != null) {
                 try {
                     sqlExecute.closeConnection();
                 } catch (SQLException e) {
-                    logger.error("Failed to close connection.", e);
+                    LOGGER.error("Failed to close connection.", e);
                 }
             }
         }
@@ -58,7 +58,7 @@ public class CaseController {
 
     @GetMapping("/postgres")
     public String postgres() throws SQLException {
-        logger.info("Begin to start execute sql");
+        LOGGER.info("Begin to start execute sql");
         SQLExecutor sqlExecute = null;
         try {
             sqlExecute = new SQLExecutor(postgresqlConfig);
@@ -66,14 +66,14 @@ public class CaseController {
             sqlExecute.insertData(ConstSql.INSERT_DATA_SQL, "1", "1");
             sqlExecute.dropTable(ConstSql.DROP_TABLE_SQL);
         } catch (SQLException e) {
-            logger.error("Failed to execute sql.", e);
+            LOGGER.error("Failed to execute sql.", e);
             throw e;
         } finally {
             if (sqlExecute != null) {
                 try {
                     sqlExecute.closeConnection();
                 } catch (SQLException e) {
-                    logger.error("Failed to close connection.", e);
+                    LOGGER.error("Failed to close connection.", e);
                 }
             }
         }
diff --git a/test/plugin/scenarios/postgresql-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java b/test/plugin/scenarios/postgresql-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
index 60e1f48..393299d 100644
--- a/test/plugin/scenarios/postgresql-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
+++ b/test/plugin/scenarios/postgresql-scenario/src/main/java/org/apache/skywalking/apm/testcase/postgresql/controller/CaseController.java
@@ -30,7 +30,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/postgresql-scenario/case")
 public class CaseController {
 
-    private static Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Autowired
     PostgresqlConfig postgresqlConfig;
@@ -42,14 +42,14 @@ public class CaseController {
             sqlExecute = new SQLExecutor(postgresqlConfig);
             sqlExecute.checkPG(ConstSql.TEST_SQL);
         } catch (SQLException e) {
-            logger.error("Failed to execute sql.", e);
+            LOGGER.error("Failed to execute sql.", e);
             throw e;
         } finally {
             if (sqlExecute != null) {
                 try {
                     sqlExecute.closeConnection();
                 } catch (SQLException e) {
-                    logger.error("Failed to close connection.", e);
+                    LOGGER.error("Failed to close connection.", e);
                 }
             }
         }
@@ -58,7 +58,7 @@ public class CaseController {
 
     @GetMapping("/postgres")
     public String postgres() throws SQLException {
-        logger.info("Begin to start execute sql");
+        LOGGER.info("Begin to start execute sql");
         SQLExecutor sqlExecute = null;
         try {
             sqlExecute = new SQLExecutor(postgresqlConfig);
@@ -66,14 +66,14 @@ public class CaseController {
             sqlExecute.insertData(ConstSql.INSERT_DATA_SQL, "1", "1");
             sqlExecute.dropTable(ConstSql.DROP_TABLE_SQL);
         } catch (SQLException e) {
-            logger.error("Failed to execute sql.", e);
+            LOGGER.error("Failed to execute sql.", e);
             throw e;
         } finally {
             if (sqlExecute != null) {
                 try {
                     sqlExecute.closeConnection();
                 } catch (SQLException e) {
-                    logger.error("Failed to close connection.", e);
+                    LOGGER.error("Failed to close connection.", e);
                 }
             }
         }
diff --git a/test/plugin/scenarios/pulsar-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/pulsar/controller/CaseController.java b/test/plugin/scenarios/pulsar-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/pulsar/controller/CaseController.java
index 2aa8ba7..0442dfa 100644
--- a/test/plugin/scenarios/pulsar-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/pulsar/controller/CaseController.java
+++ b/test/plugin/scenarios/pulsar-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/pulsar/controller/CaseController.java
@@ -38,7 +38,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @PropertySource("classpath:application.properties")
 public class CaseController {
 
-    private Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String PULSAR_DOMAIN = "pulsar://";
 
@@ -69,13 +69,13 @@ public class CaseController {
                     StringBuilder builder = new StringBuilder();
                     msg.getProperties()
                        .forEach((k, v) -> builder.append(String.format(propertiesFormat, k, v)).append(", "));
-                    logger.info("Received message with messageId = {}, key = {}, value = {}, properties = {}", msg.getMessageId(), msg
+                    LOGGER.info("Received message with messageId = {}, key = {}, value = {}, properties = {}", msg.getMessageId(), msg
                         .getKey(), new String(msg.getValue()), builder.toString());
 
                 }
                 consumer.acknowledge(msg);
             } catch (PulsarClientException e) {
-                logger.error("Receive message error", e);
+                LOGGER.error("Receive message error", e);
             } finally {
                 latch.countDown();
             }
@@ -86,7 +86,7 @@ public class CaseController {
         try {
             latch.await(3, TimeUnit.SECONDS);
         } catch (InterruptedException e) {
-            logger.error("Can get message from consumer", e);
+            LOGGER.error("Can get message from consumer", e);
             t.interrupt();
             throw e;
         }
diff --git a/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/Application.java b/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/Application.java
index 8f67558..542c372 100644
--- a/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/Application.java
+++ b/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/Application.java
@@ -26,13 +26,13 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 @SpringBootApplication
 public class Application {
 
-    private static final Logger logger = LogManager.getLogger(Application.class);
+    private static final Logger LOGGER = LogManager.getLogger(Application.class);
 
     public static void main(String[] args) {
         try {
             SpringApplication.run(Application.class, args);
         } catch (Exception ex) {
-            logger.error("Application start error", ex);
+            LOGGER.error("Application start error", ex);
             throw ex;
         }
     }
diff --git a/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/controller/CaseController.java b/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/controller/CaseController.java
index 6635fc2..fb9ebb7 100644
--- a/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/controller/CaseController.java
+++ b/test/plugin/scenarios/quasar-scenario/src/main/java/org/apache/skywalking/apm/testcase/quasar/controller/CaseController.java
@@ -36,7 +36,7 @@ import java.io.IOException;
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String SUCCESS = "Success";
 
@@ -49,7 +49,7 @@ public class CaseController {
                 try {
                     call("http://localhost:8080/quasar-scenario/case/ping");
                 } catch (Exception e) {
-                    logger.error("quasar error:", e);
+                    LOGGER.error("quasar error:", e);
                 }
                 return null;
             }
diff --git a/test/plugin/scenarios/rabbitmq-scenario/src/main/java/org/apache/skywalking/apm/testcase/rabbitmq/controller/CaseController.java b/test/plugin/scenarios/rabbitmq-scenario/src/main/java/org/apache/skywalking/apm/testcase/rabbitmq/controller/CaseController.java
index e6e00cd..817c6e4 100644
--- a/test/plugin/scenarios/rabbitmq-scenario/src/main/java/org/apache/skywalking/apm/testcase/rabbitmq/controller/CaseController.java
+++ b/test/plugin/scenarios/rabbitmq-scenario/src/main/java/org/apache/skywalking/apm/testcase/rabbitmq/controller/CaseController.java
@@ -39,7 +39,7 @@ import org.springframework.web.bind.annotation.RestController;
 @PropertySource("classpath:application.properties")
 public class CaseController {
 
-    private Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private static final String USERNAME = "admin";
 
@@ -62,7 +62,7 @@ public class CaseController {
 
         try {
             ConnectionFactory factory = new ConnectionFactory();
-            logger.info("Using brokerUrl = " + brokerUrl);
+            LOGGER.info("Using brokerUrl = " + brokerUrl);
             factory.setHost(brokerUrl);
             factory.setPort(PORT);
             factory.setUsername(USERNAME);
@@ -73,23 +73,23 @@ public class CaseController {
             channel = connection.createChannel();
             channel.queueDeclare(QUEUE_NAME, false, false, false, null);
             AMQP.BasicProperties.Builder propsBuilder = new AMQP.BasicProperties.Builder();
-            logger.info("Message being published -------------->" + MESSAGE);
+            LOGGER.info("Message being published -------------->" + MESSAGE);
             channel.basicPublish("", QUEUE_NAME, propsBuilder.build(), MESSAGE.getBytes(StandardCharsets.UTF_8));
-            logger.info("Message has been published-------------->" + MESSAGE);
+            LOGGER.info("Message has been published-------------->" + MESSAGE);
 
             final CountDownLatch waitForConsume = new CountDownLatch(1);
             DeliverCallback deliverCallback = (consumerTag, delivery) -> {
                 String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
-                logger.info("Message received-------------->" + message);
+                LOGGER.info("Message received-------------->" + message);
                 waitForConsume.countDown();
             };
             channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
             });
             waitForConsume.await(5000L, TimeUnit.MILLISECONDS);
-            logger.info("Message Consumed-------------->");
+            LOGGER.info("Message Consumed-------------->");
 
         } catch (Exception ex) {
-            logger.error(ex.toString());
+            LOGGER.error(ex.toString());
         } finally {
             if (channel != null) {
                 try {
@@ -116,7 +116,7 @@ public class CaseController {
 
         try {
             ConnectionFactory factory = new ConnectionFactory();
-            logger.info("Using brokerUrl = " + brokerUrl);
+            LOGGER.info("Using brokerUrl = " + brokerUrl);
             factory.setHost(brokerUrl);
             factory.setPort(PORT);
             factory.setUsername(USERNAME);
@@ -126,9 +126,9 @@ public class CaseController {
 
             channel = connection.createChannel();
             channel.queueDeclare(QUEUE_NAME, false, false, false, null);
-            logger.info("Completed Health Check. Able to connect to RabbitMQ and create queue-------------->");
+            LOGGER.info("Completed Health Check. Able to connect to RabbitMQ and create queue-------------->");
         } catch (Exception ex) {
-            logger.error(ex.toString());
+            LOGGER.error(ex.toString());
             throw ex;
         } finally {
             if (channel != null) {
diff --git a/test/plugin/scenarios/resttemplate-4.x-scenario/src/main/java/org/apache/skywalking/testcase/resttemplate/FrontController.java b/test/plugin/scenarios/resttemplate-4.x-scenario/src/main/java/org/apache/skywalking/testcase/resttemplate/FrontController.java
index 5798cc5..7c1c6ba 100644
--- a/test/plugin/scenarios/resttemplate-4.x-scenario/src/main/java/org/apache/skywalking/testcase/resttemplate/FrontController.java
+++ b/test/plugin/scenarios/resttemplate-4.x-scenario/src/main/java/org/apache/skywalking/testcase/resttemplate/FrontController.java
@@ -33,7 +33,7 @@ import org.springframework.web.client.RestTemplate;
 @RequestMapping("/resttemplate/case")
 public class FrontController {
 
-    private static Logger logger = LogManager.getLogger(FrontController.class);
+    private static final Logger LOGGER = LogManager.getLogger(FrontController.class);
 
     @Autowired
     private AsyncRestTemplate asyncRestTemplate;
@@ -60,7 +60,7 @@ public class FrontController {
         try {
             forEntity.get();
         } catch (Exception e) {
-            logger.error("exception:", e);
+            LOGGER.error("exception:", e);
         }
 
         return "Success";
diff --git a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/Application.java b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/Application.java
index 3bfbfca..c55539b 100644
--- a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/Application.java
+++ b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/Application.java
@@ -27,7 +27,7 @@ import org.springframework.web.client.RestTemplate;
 
 @SpringBootApplication
 public class Application {
-    private static final Logger logger = LogManager.getLogger(Application.class);
+    private static final Logger LOGGER = LogManager.getLogger(Application.class);
 
     @Bean
     public RestTemplate restTemplate() {
diff --git a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/RetransformUtil.java b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/RetransformUtil.java
index 518ae79..8e9060b 100644
--- a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/RetransformUtil.java
+++ b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/RetransformUtil.java
@@ -30,7 +30,7 @@ import java.security.ProtectionDomain;
 
 public class RetransformUtil {
 
-    private static final Logger logger = LogManager.getLogger(RetransformUtil.class);
+    private static final Logger LOGGER = LogManager.getLogger(RetransformUtil.class);
     public static final String RETRANSFORMING_TAG = "_retransforming_";
     public static final String RETRANSFORM_VALUE = "hello_from_agent";
 
@@ -59,9 +59,9 @@ public class RetransformUtil {
             instrumentation.addTransformer(transformer, true);
             try {
                 instrumentation.retransformClasses(CaseController.class);
-                logger.info("retransform classes success");
+                LOGGER.info("retransform classes success");
             } catch (Throwable e) {
-                logger.error("retransform classes failure", e);
+                LOGGER.error("retransform classes failure", e);
             }
 
         } finally {
diff --git a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/controller/CaseController.java b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/controller/CaseController.java
index 661826e..e28ab72 100644
--- a/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/controller/CaseController.java
+++ b/test/plugin/scenarios/retransform-class-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/retransform_class/controller/CaseController.java
@@ -32,17 +32,17 @@ import test.org.apache.skywalking.apm.testcase.retransform_class.RetransformUtil
 @RequestMapping("/case")
 public class CaseController {
 
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
     private static final String SUCCESS = "Success";
 
     @RequestMapping("/retransform-class-scenario")
     @ResponseBody
     public ResponseEntity testcase() throws HttpStatusCodeException {
         if (RetransformUtil.RETRANSFORMING_TAG.equals(RetransformUtil.RETRANSFORM_VALUE)) {
-            logger.info("retransform check success.");
+            LOGGER.info("retransform check success.");
             return ResponseEntity.ok("retransform success");
         } else {
-            logger.info("retransform check failure.");
+            LOGGER.info("retransform check failure.");
             return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("retransform failure");
         }
     }
diff --git a/test/plugin/scenarios/solrj-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/solrj/controller/CaseController.java b/test/plugin/scenarios/solrj-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/solrj/controller/CaseController.java
index c000128..99abba9 100644
--- a/test/plugin/scenarios/solrj-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/solrj/controller/CaseController.java
+++ b/test/plugin/scenarios/solrj-7.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/solrj/controller/CaseController.java
@@ -37,7 +37,7 @@ import org.springframework.web.bind.annotation.RestController;
 @RestController
 @RequestMapping("/solrj-scenario/case")
 public class CaseController {
-    private Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Value("${SOLR_SERVER}")
     private String host;
diff --git a/test/plugin/scenarios/spring-3.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java b/test/plugin/scenarios/spring-3.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
index a3ed980..19b0161 100644
--- a/test/plugin/scenarios/spring-3.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
+++ b/test/plugin/scenarios/spring-3.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
@@ -36,7 +36,7 @@ public class RestTemplateController {
 
     private static final String SUCCESS = "Success";
 
-    private Logger logger = LogManager.getLogger(RestTemplateController.class);
+    private static final Logger LOGGER = LogManager.getLogger(RestTemplateController.class);
 
     private static final String url = "http://localhost:8080/spring-3.1.x-scenario";
 
@@ -45,7 +45,7 @@ public class RestTemplateController {
     public String restTemplate() throws IOException {
         Request request = new Request.Builder().url(url + "/case/spring3/").build();
         Response response = new OkHttpClient().newCall(request).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         // Create user
         HttpEntity<User> userEntity = new HttpEntity<>(new User(1, "a"));
diff --git a/test/plugin/scenarios/spring-4.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java b/test/plugin/scenarios/spring-4.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
index c9f6745..d8c475e 100644
--- a/test/plugin/scenarios/spring-4.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
+++ b/test/plugin/scenarios/spring-4.1.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
@@ -36,7 +36,7 @@ public class RestTemplateController {
 
     private static final String SUCCESS = "Success";
 
-    private Logger logger = LogManager.getLogger(RestTemplateController.class);
+    private static final Logger LOGGER = LogManager.getLogger(RestTemplateController.class);
 
     private static final String url = "http://localhost:8080/spring-4.1.x-scenario";
 
@@ -45,7 +45,7 @@ public class RestTemplateController {
     public String restTemplate() throws IOException {
         Request request = new Request.Builder().url(url + "/case/spring3/").build();
         Response response = new OkHttpClient().newCall(request).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         // Create user
         HttpEntity<User> userEntity = new HttpEntity<>(new User(1, "a"));
diff --git a/test/plugin/scenarios/spring-4.3.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java b/test/plugin/scenarios/spring-4.3.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
index 0d4a851..ea3dc65 100644
--- a/test/plugin/scenarios/spring-4.3.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
+++ b/test/plugin/scenarios/spring-4.3.x-scenario/src/main/java/test/org/apache/skywalking/apm/testcase/resttemplate/RestTemplateController.java
@@ -36,7 +36,7 @@ public class RestTemplateController {
 
     private static final String SUCCESS = "Success";
 
-    private Logger logger = LogManager.getLogger(RestTemplateController.class);
+    private static final Logger LOGGER = LogManager.getLogger(RestTemplateController.class);
 
     private static final String url = "http://localhost:8080/spring-4.3.x-scenario";
 
@@ -45,7 +45,7 @@ public class RestTemplateController {
     public String restTemplate() throws IOException {
         Request request = new Request.Builder().header("mock_header", "mock_value").url(url + "/case/spring3/").build();
         Response response = new OkHttpClient().newCall(request).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         // Create user
         HttpEntity<User> userEntity = new HttpEntity<>(new User(1, "a"));
@@ -63,15 +63,15 @@ public class RestTemplateController {
 
         Request inheritRequest = new Request.Builder().url(url + "/inherit/child/test").build();
         response = new OkHttpClient().newCall(inheritRequest).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         Request implRequestMappingRequest = new Request.Builder().url(url + "/impl/requestmapping").build();
         response = new OkHttpClient().newCall(implRequestMappingRequest).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         Request implRestMappingRequest = new Request.Builder().url(url + "/impl/restmapping").build();
         response = new OkHttpClient().newCall(implRestMappingRequest).execute();
-        logger.info(response.toString());
+        LOGGER.info(response.toString());
 
         return SUCCESS;
     }
diff --git a/test/plugin/scenarios/spring-cloud-feign-1.2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java b/test/plugin/scenarios/spring-cloud-feign-1.2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
index 750441c..2d52b1d 100644
--- a/test/plugin/scenarios/spring-cloud-feign-1.2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
+++ b/test/plugin/scenarios/spring-cloud-feign-1.2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
@@ -28,7 +28,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @Controller
 @RequestMapping("/case")
 public class CaseController {
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     @Autowired
     private RestRequest restRequest;
@@ -43,7 +43,7 @@ public class CaseController {
     @RequestMapping("/spring-cloud-feign-1.2.x-scenario")
     public String feignCase() {
         String user = restRequest.getById();
-        logger.info(user);
+        LOGGER.info(user);
         return "success";
     }
 }
diff --git a/test/plugin/scenarios/spring-cloud-feign-2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java b/test/plugin/scenarios/spring-cloud-feign-2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
index b6ecac3..ca44ea7 100644
--- a/test/plugin/scenarios/spring-cloud-feign-2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
+++ b/test/plugin/scenarios/spring-cloud-feign-2.x-scenario/src/main/java/org/apache/skywalking/apm/testcase/feign/controller/CaseController.java
@@ -28,7 +28,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @Controller
 @RequestMapping("/case")
 public class CaseController {
-    private static final Logger logger = LogManager.getLogger(CaseController.class);
+    private static final Logger LOGGER = LogManager.getLogger(CaseController.class);
 
     private RestRequest restRequest;
 
@@ -47,7 +47,7 @@ public class CaseController {
     public String feignCase() {
         restRequest.createUser(new User(1, "test"));
         User user = restRequest.getById(1);
-        logger.info("find Id{} user. User name is {} ", user.getId(), user.getUserName());
+        LOGGER.info("find Id{} user. User name is {} ", user.getId(), user.getUserName());
         restRequest.updateUser(1, new User(0, "testA"));
         restRequest.deleteUser(1);
         return "success";
diff --git a/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/Zookeeper.java b/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/Zookeeper.java
index 2958d51..4eb36a3 100644
--- a/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/Zookeeper.java
+++ b/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/Zookeeper.java
@@ -31,14 +31,14 @@ import org.springframework.context.annotation.PropertySource;
 @PropertySource("classpath:application.properties")
 public class Zookeeper {
 
-    private Logger logger = LoggerFactory.getLogger(Zookeeper.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(Zookeeper.class);
 
     @Value(value = "${zookeeper.host}")
     private String address;
 
     @Bean
     public ZooKeeper zooKeeper() throws IOException {
-        ZooKeeper zooKeeper = new ZooKeeper(address, 8000, event -> logger.info("process"));
+        ZooKeeper zooKeeper = new ZooKeeper(address, 8000, event -> LOGGER.info("process"));
         return zooKeeper;
     }
 }
diff --git a/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/ZookeeperController.java b/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/ZookeeperController.java
index dafbb83..424986c 100644
--- a/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/ZookeeperController.java
+++ b/test/plugin/scenarios/zookeeper-scenario/src/main/java/org/apache/skywalking/apm/testcase/zookeeper/controller/ZookeeperController.java
@@ -36,7 +36,7 @@ import org.springframework.web.bind.annotation.ResponseBody;
 @RequestMapping("/case")
 @PropertySource("classpath:application.properties")
 public class ZookeeperController {
-    private Logger logger = LoggerFactory.getLogger(ZookeeperController.class);
+    private static final Logger LOGGER = LoggerFactory.getLogger(ZookeeperController.class);
 
     @Autowired
     private ZooKeeper zooKeeper;
@@ -62,7 +62,7 @@ public class ZookeeperController {
             try {
                 zooKeeper.exists("/path", this);
             } catch (Exception e) {
-                logger.error("error", e);
+                LOGGER.error("error", e);
             }
         }
     };