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Posted to commits@lens.apache.org by jd...@apache.org on 2015/06/23 12:24:51 UTC

[03/51] [abbrv] incubator-lens git commit: LENS-551: Cleanup testcases of exception stack traces

LENS-551: Cleanup testcases of exception stack traces


Project: http://git-wip-us.apache.org/repos/asf/incubator-lens/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-lens/commit/b0783db7
Tree: http://git-wip-us.apache.org/repos/asf/incubator-lens/tree/b0783db7
Diff: http://git-wip-us.apache.org/repos/asf/incubator-lens/diff/b0783db7

Branch: refs/heads/current-release-line
Commit: b0783db7976d207b6544dcf2d9f8e5685994f9b4
Parents: 82553db
Author: Yash Sharma <ya...@gmail.com>
Authored: Wed May 27 20:01:26 2015 +0530
Committer: Rajat Khandelwal <ra...@gmail.com>
Committed: Wed May 27 20:01:26 2015 +0530

----------------------------------------------------------------------
 checkstyle/src/main/resources/checkstyle.xml    |   7 +
 .../lens/cli/commands/BaseLensCommand.java      |  10 +-
 .../cli/commands/LensConnectionCommands.java    |   7 +-
 .../lens/cli/TestLensDimensionCommands.java     |  16 +-
 .../cli/TestLensDimensionTableCommands.java     |  24 ++-
 .../apache/lens/cli/TestLensFactCommands.java   |  27 ++-
 .../apache/lens/cli/TestLensQueryCommands.java  |  31 ++-
 .../apache/lens/client/jdbc/LensJdbcDriver.java |   6 +-
 .../org/apache/lens/cube/parse/HQLParser.java   |   7 +-
 .../timeline/TestPartitionTimelines.java        |   6 +-
 .../apache/lens/cube/parse/CubeTestSetup.java   |   6 +-
 .../lens/cube/parse/TestCubeRewriter.java       |   7 +-
 .../apache/lens/cube/parse/TestDateUtil.java    |   6 +-
 .../apache/lens/cube/parse/TestHQLParser.java   |   6 +-
 .../lens/cube/parse/TestMaxUpdateInterval.java  |   6 +-
 .../lens/cube/parse/TestQueryRewrite.java       |   3 +-
 .../lens/cube/parse/TestTimeRangeWriter.java    |   5 +-
 .../parse/TestTimeRangeWriterWithQuery.java     |   6 +-
 .../org/apache/lens/driver/hive/HiveDriver.java |  95 +++++----
 .../lens/driver/hive/HiveInMemoryResultSet.java |   5 +-
 .../apache/lens/driver/hive/HiveQueryPlan.java  |   5 +-
 .../lens/driver/hive/TestRemoteHiveDriver.java  |  27 ++-
 .../driver/jdbc/TestColumnarSQLRewriter.java    |   7 +-
 .../jdbc/TestDataSourceConnectionProvider.java  |  15 +-
 .../apache/lens/driver/jdbc/TestJdbcDriver.java |  32 ++--
 .../apache/lens/examples/SampleMetastore.java   |   6 +-
 .../org/apache/lens/client/LensMLClient.java    |   9 +-
 .../apache/lens/ml/algo/lib/AlgoArgParser.java  |  11 +-
 .../org/apache/lens/ml/impl/LensMLImpl.java     |  71 ++++---
 .../java/org/apache/lens/ml/TestMLResource.java |  25 ++-
 .../apache/lens/server/LensRequestListener.java |   5 +-
 .../lens/server/LensServletContextListener.java |   5 +-
 .../metastore/CubeMetastoreServiceImpl.java     |  76 ++++----
 .../apache/lens/server/metastore/JAXBUtils.java |  12 +-
 .../lens/server/metrics/MetricsServiceImpl.java |  17 +-
 .../apache/lens/server/query/LensServerDAO.java |  21 +-
 .../server/query/QueryExecutionServiceImpl.java | 191 +++++++++----------
 .../lens/server/query/QueryServiceResource.java |  16 +-
 .../lens/server/session/HiveSessionService.java |  50 +++--
 .../event/query/QueryExecutionStatistics.java   |   6 +-
 .../org/apache/lens/server/LensTestUtil.java    |   6 +-
 .../server/metastore/TestMetastoreService.java  |  18 +-
 .../lens/server/query/TestQueryService.java     |  22 +--
 .../session/TestDatabaseResourceService.java    |  10 +-
 .../stats/TestStatisticsLogFileScannerTask.java |   5 +-
 45 files changed, 498 insertions(+), 456 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/checkstyle/src/main/resources/checkstyle.xml
----------------------------------------------------------------------
diff --git a/checkstyle/src/main/resources/checkstyle.xml b/checkstyle/src/main/resources/checkstyle.xml
index d6ff839..031d664 100644
--- a/checkstyle/src/main/resources/checkstyle.xml
+++ b/checkstyle/src/main/resources/checkstyle.xml
@@ -245,6 +245,13 @@
         <property name="checkFormat" value="ParameterNumberCheck|VisibilityModifierCheck|HiddenFieldCheck|MethodName|HideUtilityClassConstructorCheck|DoubleCheckedLockingCheck|InnerAssignmentCheck"/>
     </module>
 
+    <module name="RegexpSingleline">
+        <property name="severity" value="error" />
+        <property name="format" value="\w*.printStackTrace\w*"  />
+        <property name="message" value="Print stack trace not allowed. Use Logger." />
+        <property name="fileExtensions" value="java" />
+    </module>
+
     <!--module name="SuppressionFilter">
       <property name="file" value="checkstyle/src/main/resources/suppressions.xml"/>
     </module-->

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/main/java/org/apache/lens/cli/commands/BaseLensCommand.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/main/java/org/apache/lens/cli/commands/BaseLensCommand.java b/lens-cli/src/main/java/org/apache/lens/cli/commands/BaseLensCommand.java
index d6055cd..3deddfa 100644
--- a/lens-cli/src/main/java/org/apache/lens/cli/commands/BaseLensCommand.java
+++ b/lens-cli/src/main/java/org/apache/lens/cli/commands/BaseLensCommand.java
@@ -27,8 +27,6 @@ import java.util.Date;
 import org.apache.lens.client.LensClient;
 import org.apache.lens.client.LensClientSingletonWrapper;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 
 import org.codehaus.jackson.JsonGenerationException;
 import org.codehaus.jackson.JsonGenerator;
@@ -41,9 +39,12 @@ import org.springframework.shell.event.ParseResult;
 
 import com.google.common.collect.Sets;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class BaseLensCommand.
  */
+@Slf4j
 public class BaseLensCommand implements ExecutionProcessor {
 
   /** The mapper. */
@@ -52,9 +53,6 @@ public class BaseLensCommand implements ExecutionProcessor {
   /** The pp. */
   protected DefaultPrettyPrinter pp;
 
-  /** The Constant LOG. */
-  public static final Log LOG = LogFactory.getLog(BaseLensCommand.class);
-
   /** The is connection active. */
   protected static boolean isConnectionActive;
   public static final String DATE_FMT = "yyyy-MM-dd'T'HH:mm:ss:SSS";
@@ -84,7 +82,7 @@ public class BaseLensCommand implements ExecutionProcessor {
    */
   protected static synchronized void closeClientConnection() {
     if (isConnectionActive) {
-      LOG.debug("Request for stopping lens cli received");
+      log.debug("Request for stopping lens cli received");
       getClient().closeConnection();
       isConnectionActive = false;
     }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/main/java/org/apache/lens/cli/commands/LensConnectionCommands.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/main/java/org/apache/lens/cli/commands/LensConnectionCommands.java b/lens-cli/src/main/java/org/apache/lens/cli/commands/LensConnectionCommands.java
index d727ecc..675e6c8 100644
--- a/lens-cli/src/main/java/org/apache/lens/cli/commands/LensConnectionCommands.java
+++ b/lens-cli/src/main/java/org/apache/lens/cli/commands/LensConnectionCommands.java
@@ -32,9 +32,13 @@ import org.springframework.stereotype.Component;
 
 import com.google.common.base.Joiner;
 
+import lombok.extern.slf4j.Slf4j;
+
+
 /**
  * The Class LensConnectionCommands.
  */
+@Slf4j
 @Component
 @UserDocumentation(title = "Session management",
   description = "Opening the lens CLI shell is equivalent to open a session with lens server."
@@ -159,8 +163,7 @@ public class LensConnectionCommands extends BaseLensCommand {
       closeClientConnection();
       return ExitShellRequest.NORMAL_EXIT;
     } catch (ProcessingException e) {
-      System.out.println(e.getMessage());
-      LOG.error(e);
+      log.error("Error while closing client connection.", e);
       return ExitShellRequest.FATAL_EXIT;
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionCommands.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionCommands.java b/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionCommands.java
index 5df3486..208eb78 100644
--- a/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionCommands.java
+++ b/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionCommands.java
@@ -25,19 +25,17 @@ import java.net.URL;
 import org.apache.lens.cli.commands.LensDimensionCommands;
 import org.apache.lens.client.LensClient;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestLensDimensionCommands.
  */
+@Slf4j
 public class TestLensDimensionCommands extends LensCliApplicationTest {
 
-  /** The Constant LOG. */
-  private static final Logger LOG = LoggerFactory.getLogger(TestLensDimensionCommands.class);
-
   /** The command. */
   private static LensDimensionCommands command = null;
 
@@ -69,7 +67,7 @@ public class TestLensDimensionCommands extends LensCliApplicationTest {
    */
   @Test
   public void testDimensionCommands() throws Exception {
-    LOG.debug("Starting to test dimension commands");
+    log.debug("Starting to test dimension commands");
     URL dimensionSpec = TestLensDimensionCommands.class.getClassLoader().getResource("test-dimension.xml");
     String dimensionList = getCommand().showDimensions();
     Assert.assertFalse(dimensionList.contains("test_dim"));
@@ -114,14 +112,14 @@ public class TestLensDimensionCommands extends LensCliApplicationTest {
       writer.close();
 
       String desc = command.describeDimension("test_dim");
-      LOG.debug(desc);
+      log.debug(desc);
       String propString = "name : test_dim.prop  value : test";
       String propString1 = "name : test_dim.prop1  value : test1";
       Assert.assertTrue(desc.contains(propString));
 
       command.updateDimension("test_dim", "/tmp/test_dim1.xml");
       desc = command.describeDimension("test_dim");
-      LOG.debug(desc);
+      log.debug(desc);
       Assert.assertTrue(desc.contains(propString));
 
       Assert.assertTrue(desc.contains(propString1));
@@ -129,7 +127,7 @@ public class TestLensDimensionCommands extends LensCliApplicationTest {
       newFile.delete();
 
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Testing update dimension failed with exception", t);
       Assert.fail("Testing update dimension failed with exception" + t.getMessage());
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionTableCommands.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionTableCommands.java b/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionTableCommands.java
index a98f183..a87d0b7 100644
--- a/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionTableCommands.java
+++ b/lens-cli/src/test/java/org/apache/lens/cli/TestLensDimensionTableCommands.java
@@ -28,19 +28,17 @@ import org.apache.lens.cli.commands.LensDimensionCommands;
 import org.apache.lens.cli.commands.LensDimensionTableCommands;
 import org.apache.lens.client.LensClient;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestLensDimensionTableCommands.
  */
+@Slf4j
 public class TestLensDimensionTableCommands extends LensCliApplicationTest {
 
-  /** The Constant LOG. */
-  private static final Logger LOG = LoggerFactory.getLogger(TestLensDimensionTableCommands.class);
-
   /** The Constant DIM_LOCAL. */
   public static final String DIM_LOCAL = "dim_local";
 
@@ -116,7 +114,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
     try {
       command.createDimensionTable(new File(dimSpec.toURI()).getAbsolutePath());
     } catch (Exception e) {
-      e.printStackTrace();
+      log.error("Unable to create dimtable", e);
       Assert.fail("Unable to create dimtable" + e.getMessage());
     }
 
@@ -126,13 +124,13 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
       Assert.assertEquals(command.showDimensionTables("blah"), dimList);
       Assert.fail();
     } catch (NotFoundException e) {
-      LOG.info("blah is not a table", e);
+      log.info("blah is not a table", e);
     }
     try {
       Assert.assertEquals(command.showDimensionTables("dim_table2"), dimList);
       Assert.fail();
     } catch (NotFoundException e) {
-      LOG.info("dim_table2 is a table, but not a dimension", e);
+      log.info("dim_table2 is a table, but not a dimension", e);
     }
     Assert.assertTrue(dimList.contains(tableName), "dim_table table should be found");
   }
@@ -166,7 +164,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
       writer.close();
 
       String desc = command.describeDimensionTable("dim_table2");
-      LOG.debug(desc);
+      log.debug(desc);
       String propString = "name : dim2.prop  value : d2";
       String propString1 = "name : dim2.prop  value : d1";
       String propString2 = "name : dim2.prop1  value : d2";
@@ -174,7 +172,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
 
       command.updateDimensionTable("dim_table2", "/tmp/local-dim1.xml");
       desc = command.describeDimensionTable("dim_table2");
-      LOG.debug(desc);
+      log.debug(desc);
       Assert.assertTrue(desc.contains(propString1));
       Assert.assertTrue(desc.contains(propString2));
 
@@ -234,7 +232,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
       command.addPartitionToDimtable("dim_table2", DIM_LOCAL, new File(
         TestLensFactCommands.class.getClassLoader().getResource("dim1-local-part.xml").toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to dim table dim_table2", t);
       Assert.fail("Unable to locate the storage part file for adding new storage to dim table dim_table2");
     }
     verifyAndDeletePartition();
@@ -242,7 +240,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
       command.addPartitionsToDimtable("dim_table2", DIM_LOCAL, new File(
         TestLensFactCommands.class.getClassLoader().getResource("dim1-local-parts.xml").toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to dim table dim_table2", t);
       Assert.fail("Unable to locate the storage part file for adding new storage to dim table dim_table2");
     }
     verifyAndDeletePartition();
@@ -270,7 +268,7 @@ public class TestLensDimensionTableCommands extends LensCliApplicationTest {
     try {
       command.addPartitionToDimtable(tableName, storageName, new File(resource.toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to dim table dim_table2", t);
       Assert.fail("Unable to locate the storage part file for adding new storage to dim table dim_table2");
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/test/java/org/apache/lens/cli/TestLensFactCommands.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/test/java/org/apache/lens/cli/TestLensFactCommands.java b/lens-cli/src/test/java/org/apache/lens/cli/TestLensFactCommands.java
index 19979cc..1ad234d 100644
--- a/lens-cli/src/test/java/org/apache/lens/cli/TestLensFactCommands.java
+++ b/lens-cli/src/test/java/org/apache/lens/cli/TestLensFactCommands.java
@@ -31,18 +31,16 @@ import org.apache.lens.cli.commands.LensCubeCommands;
 import org.apache.lens.cli.commands.LensFactCommands;
 import org.apache.lens.client.LensClient;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestLensFactCommands.
  */
+@Slf4j
 public class TestLensFactCommands extends LensCliApplicationTest {
 
-  /** The Constant LOG. */
-  private static final Logger LOG = LoggerFactory.getLogger(TestLensFactCommands.class);
-
   /** The Constant FACT_LOCAL. */
   public static final String FACT_LOCAL = "fact_local";
 
@@ -119,13 +117,13 @@ public class TestLensFactCommands extends LensCliApplicationTest {
       assertEquals(command.showFacts("blah"), factList);
       fail();
     } catch (NotFoundException e) {
-      LOG.info("blah is not a table", e);
+      log.info("blah is not a table", e);
     }
     try {
       assertEquals(command.showFacts("fact1"), factList);
       fail();
     } catch (NotFoundException e) {
-      LOG.info("fact1 is a table, but not a cube table", e);
+      log.info("fact1 is a table, but not a cube table", e);
     }
     assertEquals("fact1", factList, "Fact1 table should be found");
   }
@@ -157,7 +155,7 @@ public class TestLensFactCommands extends LensCliApplicationTest {
       writer.close();
 
       String desc = command.describeFactTable("fact1");
-      LOG.debug(desc);
+      log.debug(desc);
       String propString = "name : fact1.prop  value : f1";
       String propString1 = "name : fact1.prop1  value : f2";
 
@@ -165,15 +163,14 @@ public class TestLensFactCommands extends LensCliApplicationTest {
 
       command.updateFactTable("fact1", "/tmp/local-fact1.xml");
       desc = command.describeFactTable("fact1");
-      LOG.debug(desc);
+      log.debug(desc);
       assertTrue(desc.contains(propString), "The sample property value is not set");
-
       assertTrue(desc.contains(propString1), "The sample property value is not set");
 
       newFile.delete();
 
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Updating of the fact1 table failed with ", t);
       fail("Updating of the fact1 table failed with " + t.getMessage());
     }
 
@@ -208,7 +205,7 @@ public class TestLensFactCommands extends LensCliApplicationTest {
     try {
       command.addNewFactStorage("fact1", new File(resource.toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to fact table fact1", t);
       fail("Unable to locate the storage part file for adding new storage to fact table fact1");
     }
     result = command.getFactStorages("fact1");
@@ -233,15 +230,15 @@ public class TestLensFactCommands extends LensCliApplicationTest {
       command.addPartitionToFact("fact1", FACT_LOCAL, new File(
         TestLensFactCommands.class.getClassLoader().getResource("fact1-local-part.xml").toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to fact table fact1", t);
       fail("Unable to locate the storage part file for adding new storage to fact table fact1");
     }
     verifyAndDeletePartitions();
     try {
       command.addPartitionsToFact("fact1", FACT_LOCAL, new File(
-        TestLensFactCommands.class.getClassLoader().getResource("fact1-local-parts.xml").toURI()).getAbsolutePath());
+          TestLensFactCommands.class.getClassLoader().getResource("fact1-local-parts.xml").toURI()).getAbsolutePath());
     } catch (Throwable t) {
-      t.printStackTrace();
+      log.error("Unable to locate the storage part file for adding new storage to fact table fact1", t);
       fail("Unable to locate the storage part file for adding new storage to fact table fact1");
     }
     verifyAndDeletePartitions();

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cli/src/test/java/org/apache/lens/cli/TestLensQueryCommands.java
----------------------------------------------------------------------
diff --git a/lens-cli/src/test/java/org/apache/lens/cli/TestLensQueryCommands.java b/lens-cli/src/test/java/org/apache/lens/cli/TestLensQueryCommands.java
index 5724d24..32a89ac 100644
--- a/lens-cli/src/test/java/org/apache/lens/cli/TestLensQueryCommands.java
+++ b/lens-cli/src/test/java/org/apache/lens/cli/TestLensQueryCommands.java
@@ -43,18 +43,16 @@ import org.apache.lens.driver.hive.TestHiveDriver;
 import org.apache.commons.lang.StringUtils;
 import org.apache.hadoop.fs.Path;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestLensQueryCommands.
  */
+@Slf4j
 public class TestLensQueryCommands extends LensCliApplicationTest {
 
-  /** The Constant LOG. */
-  private static final Logger LOG = LoggerFactory.getLogger(TestLensQueryCommands.class);
-
   /** The client. */
   private LensClient client;
 
@@ -130,29 +128,29 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
 
     result = qCom.executePreparedQuery(qh, false, "testPrepQuery1");
 
-    LOG.warn("XXXXXX Prepared query sync result is  " + result);
+    log.warn("XXXXXX Prepared query sync result is  " + result);
     assertTrue(result.contains("1\tfirst"));
 
     String handle = qCom.executePreparedQuery(qh, true, "testPrepQuery2");
-    LOG.debug("Perpared query handle is   " + handle);
+    log.debug("Perpared query handle is   " + handle);
     while (!client.getQueryStatus(handle).finished()) {
       Thread.sleep(5000);
     }
     String status = qCom.getStatus(handle);
-    LOG.debug("Prepared Query Status is  " + status);
+    log.debug("Prepared Query Status is  " + status);
     assertTrue(status.contains("Status : SUCCESSFUL"));
 
     result = qCom.getQueryResults(handle, null);
-    LOG.debug("Prepared Query Result is  " + result);
+    log.debug("Prepared Query Result is  " + result);
     assertTrue(result.contains("1\tfirst"));
     // Fetch again.
     result = qCom.getQueryResults(handle, null);
-    LOG.debug("Prepared Query Result is  " + result);
+    log.debug("Prepared Query Result is  " + result);
     assertTrue(result.contains("1\tfirst"));
 
     result = qCom.destroyPreparedQuery(qh);
 
-    LOG.debug("destroy result is " + result);
+    log.debug("destroy result is " + result);
     assertEquals("Successfully destroyed " + qh, result);
     result = qCom.getAllPreparedQueries("testPreparedName", "all", submitTime, Long.MAX_VALUE);
 
@@ -195,9 +193,8 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
     String sql = "cube select id, name from test_dim";
     String result = qCom.explainQuery(sql, "");
 
-    LOG.debug(result);
+    log.debug(result);
     assertTrue(result.contains(explainPlan));
-
   }
 
   /**
@@ -210,7 +207,7 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
     String sql = "cube select id2, name from test_dim";
     String result = qCom.explainQuery(sql, "");
 
-    LOG.debug(result);
+    log.debug(result);
     assertTrue(result.contains("Explain FAILED:"));
 
     result = qCom.explainAndPrepare(sql, "");
@@ -318,7 +315,7 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
     LensCubeCommands command = new LensCubeCommands();
     command.setClient(client);
 
-    LOG.debug("Starting to test cube commands");
+    log.debug("Starting to test cube commands");
     URL cubeSpec = TestLensQueryCommands.class.getClassLoader().getResource("sample-cube.xml");
     command.createCube(new File(cubeSpec.toURI()).getAbsolutePath());
     TestLensDimensionCommands.createDimension();
@@ -367,7 +364,7 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
       assertNotNull(result);
       assertFalse(result.contains("Failed to get resultset"));
     } catch (Exception exc) {
-      exc.printStackTrace();
+      log.error("Exception not expected while getting resultset.", exc);
       fail("Exception not expected: " + exc.getMessage());
     }
     System.out.println("@@END_PERSISTENT_RESULT_TEST-------------");
@@ -397,7 +394,7 @@ public class TestLensQueryCommands extends LensCliApplicationTest {
       // This is to check for positive processing time
       assertFalse(result.contains("(-"));
     } catch (Exception exc) {
-      exc.printStackTrace();
+      log.error("Exception not expected while purging resultset.", exc);
       fail("Exception not expected: " + exc.getMessage());
     }
     System.out.println("@@END_FINISHED_PURGED_RESULT_TEST-------------");

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-client/src/main/java/org/apache/lens/client/jdbc/LensJdbcDriver.java
----------------------------------------------------------------------
diff --git a/lens-client/src/main/java/org/apache/lens/client/jdbc/LensJdbcDriver.java b/lens-client/src/main/java/org/apache/lens/client/jdbc/LensJdbcDriver.java
index a6fae87..056a0b2 100644
--- a/lens-client/src/main/java/org/apache/lens/client/jdbc/LensJdbcDriver.java
+++ b/lens-client/src/main/java/org/apache/lens/client/jdbc/LensJdbcDriver.java
@@ -23,16 +23,20 @@ import java.util.Properties;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * Top level JDBC driver for Lens.
  */
+@Slf4j
 public class LensJdbcDriver implements Driver {
 
+
   static {
     try {
       DriverManager.registerDriver(new LensJdbcDriver());
     } catch (SQLException e) {
-      e.printStackTrace();
+      log.error("Error in registering jdbc driver", e);
     }
   }
 

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/main/java/org/apache/lens/cube/parse/HQLParser.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/main/java/org/apache/lens/cube/parse/HQLParser.java b/lens-cube/src/main/java/org/apache/lens/cube/parse/HQLParser.java
index 1c375ed..7b99310 100644
--- a/lens-cube/src/main/java/org/apache/lens/cube/parse/HQLParser.java
+++ b/lens-cube/src/main/java/org/apache/lens/cube/parse/HQLParser.java
@@ -40,7 +40,12 @@ import org.antlr.runtime.tree.Tree;
 
 import com.google.common.base.Optional;
 
+import lombok.extern.slf4j.Slf4j;
+
+
+@Slf4j
 public final class HQLParser {
+
   private HQLParser() {
 
   }
@@ -168,7 +173,7 @@ public final class HQLParser {
     try {
       printAST(getHiveTokenMapping(), node, 0, 0);
     } catch (Exception e) {
-      e.printStackTrace();
+      log.error("Error in printing AST.", e);
     }
     System.out.println();
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/metadata/timeline/TestPartitionTimelines.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/metadata/timeline/TestPartitionTimelines.java b/lens-cube/src/test/java/org/apache/lens/cube/metadata/timeline/TestPartitionTimelines.java
index 0231e8b..0268bbf 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/metadata/timeline/TestPartitionTimelines.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/metadata/timeline/TestPartitionTimelines.java
@@ -30,7 +30,11 @@ import org.testng.annotations.Test;
 
 import com.beust.jcommander.internal.Lists;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public class TestPartitionTimelines {
+
   private static final String TABLE_NAME = "storage_fact";
   public static final UpdatePeriod PERIOD = UpdatePeriod.HOURLY;
   private static final String PART_COL = "pt";
@@ -103,7 +107,7 @@ public class TestPartitionTimelines {
       return clz.getConstructor(String.class, UpdatePeriod.class, String.class)
         .newInstance(TABLE_NAME, PERIOD, PART_COL);
     } catch (Exception e) {
-      e.printStackTrace();
+      log.error("Error while getting instance.", e);
     }
     return null;
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/CubeTestSetup.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/CubeTestSetup.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/CubeTestSetup.java
index 1fb8556..914fe1b 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/CubeTestSetup.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/CubeTestSetup.java
@@ -1331,9 +1331,9 @@ public class CubeTestSetup {
       try {
         client.addPartition(sPartSpec, c1);
       } catch (HiveException e) {
-        e.printStackTrace();
+        log.error("Encountered Hive exception.", e);
       } catch (LensException e) {
-        e.printStackTrace();
+        log.error("Encountered Lens exception.", e);
       }
       cal.add(Calendar.HOUR_OF_DAY, 1);
       temp = cal.getTime();
@@ -2047,7 +2047,7 @@ public class CubeTestSetup {
       createStateTable(client);
       createCubeFactsWithValidColumns(client);
     } catch (Exception exc) {
-      exc.printStackTrace();
+      log.error("Exception while creating sources.", exc);
       throw exc;
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestCubeRewriter.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestCubeRewriter.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestCubeRewriter.java
index 9274ccf..0f1ad6e 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestCubeRewriter.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestCubeRewriter.java
@@ -44,6 +44,9 @@ import org.apache.hadoop.hive.ql.processors.CommandProcessorResponse;
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public class TestCubeRewriter extends TestQueryRewrite {
 
   private final String cubeName = CubeTestSetup.TEST_CUBE_NAME;
@@ -1451,7 +1454,7 @@ public class TestCubeRewriter extends TestQueryRewrite {
       assertTrue(hql.contains("`a measure`"));
       System.out.println("@@ hql: " + hql);
     } catch (NullPointerException npe) {
-      npe.printStackTrace();
+      log.error("Not expecting null pointer exception", npe);
       fail("Not expecting null pointer exception");
     }
   }
@@ -1502,7 +1505,7 @@ public class TestCubeRewriter extends TestQueryRewrite {
       System.out.println("@@HQL " + hql);
     } catch (NullPointerException npe) {
       fail(npe.getMessage());
-      npe.printStackTrace();
+      log.error("Not expecting null pointer exception", npe);
     }
   }
 

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestDateUtil.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestDateUtil.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestDateUtil.java
index a916dbf..6717b5b 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestDateUtil.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestDateUtil.java
@@ -45,10 +45,14 @@ import org.testng.annotations.Test;
 import com.beust.jcommander.internal.Sets;
 import com.google.common.collect.Lists;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * Unit tests for cube DateUtil class TestDateUtil.
  */
+@Slf4j
 public class TestDateUtil {
+
   public static final String[] TEST_PAIRS = {
     "2013-Jan-01", "2013-Jan-31", "2013-Jan-01", "2013-May-31",
     "2013-Jan-01", "2013-Dec-31", "2013-Feb-01", "2013-Apr-25",
@@ -67,7 +71,7 @@ public class TestDateUtil {
       try {
         pairs[i] = DATE_FMT.parse(TEST_PAIRS[i]);
       } catch (ParseException e) {
-        e.printStackTrace();
+        log.error("Parsing exception while setup.", e);
       }
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestHQLParser.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestHQLParser.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestHQLParser.java
index fef634d..b0b2e88 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestHQLParser.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestHQLParser.java
@@ -31,7 +31,11 @@ import org.apache.hadoop.hive.ql.parse.ParseException;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public class TestHQLParser {
+
   HiveConf conf = new HiveConf();
   @Test
   public void testGroupByOrderByGetString() throws Exception {
@@ -238,7 +242,7 @@ public class TestHQLParser {
     try {
       ASTNode tree = HQLParser.parseHQL(query, conf);
     } catch (NullPointerException exc) {
-      exc.printStackTrace();
+      log.error("should not have thrown npe", exc);
       Assert.fail("should not have thrown npe");
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestMaxUpdateInterval.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestMaxUpdateInterval.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestMaxUpdateInterval.java
index a5f64ec..7e5f38d 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestMaxUpdateInterval.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestMaxUpdateInterval.java
@@ -32,10 +32,14 @@ import org.apache.lens.cube.metadata.UpdatePeriod;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /*
  * Unit test for maxUpdateIntervalIn method in CubeFactTable
  */
+@Slf4j
 public class TestMaxUpdateInterval {
+
   public static final String[] TEST_PAIRS = {
     "2013-Jan-01", "2013-Jan-31", "2013-Jan-01", "2013-May-31",
     "2013-Jan-01", "2013-Dec-31", "2013-Feb-01", "2013-Apr-25",
@@ -54,7 +58,7 @@ public class TestMaxUpdateInterval {
         pairs[i] = DATE_FMT.parse(TEST_PAIRS[i]);
         System.out.println(pairs[i].toString());
       } catch (ParseException e) {
-        e.printStackTrace();
+        log.error("Parsing exception while testing max update interval.", e);
       }
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestQueryRewrite.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestQueryRewrite.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestQueryRewrite.java
index 994a244..d16f6a5 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestQueryRewrite.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestQueryRewrite.java
@@ -31,6 +31,7 @@ import org.apache.hadoop.hive.ql.session.SessionState;
 
 import org.codehaus.jackson.map.ObjectMapper;
 import org.codehaus.jackson.type.TypeReference;
+
 import org.testng.Assert;
 import org.testng.annotations.AfterSuite;
 import org.testng.annotations.BeforeClass;
@@ -103,7 +104,7 @@ public abstract class TestQueryRewrite {
       // unreachable
       return null;
     } catch (SemanticException e) {
-      e.printStackTrace();
+      log.error("Semantic exception in Rewrite.", e);
       return e;
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriter.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriter.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriter.java
index 106660e..453a102 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriter.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriter.java
@@ -33,6 +33,9 @@ import org.apache.hadoop.hive.ql.parse.SemanticException;
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public abstract class TestTimeRangeWriter {
 
   public abstract TimeRangeWriter getTimerangeWriter();
@@ -59,7 +62,7 @@ public abstract class TestTimeRangeWriter {
     try {
       whereClause = getTimerangeWriter().getTimeRangeWhereClause(null, "test", answeringParts);
     } catch (SemanticException e) {
-      e.printStackTrace();
+      log.error("Semantic exception while testing disjoint parts.", e);
       th = e;
     }
 

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriterWithQuery.java
----------------------------------------------------------------------
diff --git a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriterWithQuery.java b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriterWithQuery.java
index b5aaeb2..0e22ce2 100644
--- a/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriterWithQuery.java
+++ b/lens-cube/src/test/java/org/apache/lens/cube/parse/TestTimeRangeWriterWithQuery.java
@@ -36,6 +36,10 @@ import org.testng.Assert;
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
+
+@Slf4j
 public class TestTimeRangeWriterWithQuery extends TestQueryRewrite {
 
   private Configuration conf;
@@ -76,7 +80,7 @@ public class TestTimeRangeWriterWithQuery extends TestQueryRewrite {
       rewrite("cube select" + " SUM(msr2) from testCube where " + TWO_DAYS_RANGE, conf);
     } catch (SemanticException e) {
       th = e;
-      e.printStackTrace();
+      log.error("Semantic exception while testing cube query.", e);
     }
     if (!CubeTestSetup.isZerothHour()) {
       Assert.assertNotNull(th);

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java
----------------------------------------------------------------------
diff --git a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java
index 8bec5e0..052d0e2 100644
--- a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java
+++ b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveDriver.java
@@ -61,19 +61,18 @@ import org.apache.hive.service.cli.*;
 import org.apache.hive.service.cli.thrift.TOperationHandle;
 import org.apache.hive.service.cli.thrift.TProtocolVersion;
 import org.apache.hive.service.cli.thrift.TSessionHandle;
-import org.apache.log4j.Logger;
 
 import org.codehaus.jackson.map.ObjectMapper;
 import org.codehaus.jackson.type.TypeReference;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class HiveDriver.
  */
+@Slf4j
 public class HiveDriver implements LensDriver {
 
-  /** The Constant LOG. */
-  public static final Logger LOG = Logger.getLogger(HiveDriver.class);
-
   /** The Constant HIVE_CONNECTION_CLASS. */
   public static final String HIVE_CONNECTION_CLASS = "lens.driver.hive.connection.class";
 
@@ -186,15 +185,15 @@ public class HiveDriver implements LensDriver {
 
           if (thConn != null) {
             try {
-              LOG.info("Closed connection:" + expired.getConnId());
+              log.info("Closed connection:" + expired.getConnId());
               thConn.close();
             } catch (IOException e) {
-              LOG.error("Error closing connection", e);
+              log.error("Error closing connection", e);
             }
           }
         }
       } catch (InterruptedException intr) {
-        LOG.warn("Connection expiry thread interrupted", intr);
+        log.warn("Connection expiry thread interrupted", intr);
         return;
       }
     }
@@ -309,7 +308,7 @@ public class HiveDriver implements LensDriver {
     connectionExpiryThread.setName("HiveDriver-ConnectionExpiryThread");
     connectionExpiryThread.start();
     driverListeners = new ArrayList<LensEventListener<DriverEvent>>();
-    LOG.info("Hive driver inited");
+    log.info("Hive driver inited");
   }
 
   @Override
@@ -350,7 +349,7 @@ public class HiveDriver implements LensDriver {
 
   @Override
   public QueryCost estimate(AbstractQueryContext qctx) throws LensException {
-    LOG.info("Estimate: " + qctx.getDriverQuery(this));
+    log.info("Estimate: " + qctx.getDriverQuery(this));
     if (qctx.getDriverQuery(this) == null) {
       throw new NullPointerException("Null driver query for " + qctx.getUserQuery());
     }
@@ -382,7 +381,7 @@ public class HiveDriver implements LensDriver {
       // explain called again and again
       return (HiveQueryPlan) explainCtx.getDriverContext().getDriverQueryPlan(this);
     }
-    LOG.info("Explain: " + explainCtx.getDriverQuery(this));
+    log.info("Explain: " + explainCtx.getDriverQuery(this));
     Configuration explainConf = new Configuration(explainCtx.getDriverConf(this));
     explainConf.setClassLoader(explainCtx.getConf().getClassLoader());
     explainConf.setBoolean(LensConfConstants.QUERY_PERSISTENT_RESULT_INDRIVER, false);
@@ -461,7 +460,7 @@ public class HiveDriver implements LensDriver {
       qdconf.set("mapred.job.name", ctx.getQueryHandle().toString());
       OperationHandle op = getClient().executeStatement(getSession(ctx), ctx.getSelectedDriverQuery(),
         qdconf.getValByRegex(".*"));
-      LOG.info("The hive operation handle: " + op);
+      log.info("The hive operation handle: " + op);
       ctx.setDriverOpHandle(op.toString());
       hiveHandles.put(ctx.getQueryHandle(), op);
       updateStatus(ctx);
@@ -498,24 +497,24 @@ public class HiveDriver implements LensDriver {
       Configuration qdconf = ctx.getDriverConf(this);
       qdconf.set("mapred.job.name", ctx.getQueryHandle().toString());
       //Query is already explained.
-      LOG.info("whetherCalculatePriority: " + whetherCalculatePriority);
+      log.info("whetherCalculatePriority: " + whetherCalculatePriority);
       if (whetherCalculatePriority) {
         try {
           // Inside try since non-data fetching queries can also be executed by async method.
           String priority = queryPriorityDecider.decidePriority(ctx).toString();
           qdconf.set("mapred.job.priority", priority);
-          LOG.info("set priority to " + priority);
+          log.info("set priority to " + priority);
         } catch (Exception e) {
           // not failing query launch when setting priority fails
           // priority will be set to usually NORMAL - the default in underlying system.
-          LOG.error("could not set priority for lens session id:" + ctx.getLensSessionIdentifier()
+          log.error("could not set priority for lens session id:" + ctx.getLensSessionIdentifier()
             + "User query: " + ctx.getUserQuery(), e);
         }
       }
       OperationHandle op = getClient().executeStatementAsync(getSession(ctx), ctx.getSelectedDriverQuery(),
         qdconf.getValByRegex(".*"));
       ctx.setDriverOpHandle(op.toString());
-      LOG.info("QueryHandle: " + ctx.getQueryHandle() + " HiveHandle:" + op);
+      log.info("QueryHandle: " + ctx.getQueryHandle() + " HiveHandle:" + op);
       hiveHandles.put(ctx.getQueryHandle(), op);
     } catch (IOException e) {
       throw new LensException("Error adding persistent path", e);
@@ -532,7 +531,7 @@ public class HiveDriver implements LensDriver {
    */
   @Override
   public void updateStatus(QueryContext context) throws LensException {
-    LOG.debug("GetStatus: " + context.getQueryHandle());
+    log.debug("GetStatus: " + context.getQueryHandle());
     if (context.getDriverStatus().isFinished()) {
       return;
     }
@@ -540,9 +539,9 @@ public class HiveDriver implements LensDriver {
     ByteArrayInputStream in = null;
     try {
       // Get operation status from hive server
-      LOG.debug("GetStatus hiveHandle: " + hiveHandle);
+      log.debug("GetStatus hiveHandle: " + hiveHandle);
       OperationStatus opStatus = getClient().getOperationStatus(hiveHandle);
-      LOG.debug("GetStatus on hiveHandle: " + hiveHandle + " returned state:" + opStatus.getState().name());
+      log.debug("GetStatus on hiveHandle: " + hiveHandle + " returned state:" + opStatus.getState().name());
 
       switch (opStatus.getState()) {
       case CANCELED:
@@ -605,7 +604,7 @@ public class HiveDriver implements LensDriver {
         progress = taskStatuses.size() == 0 ? 0 : (float) completedTasks / taskStatuses.size();
         errorMsg = errorMessage.toString();
       } else {
-        LOG.warn("Empty task statuses");
+        log.warn("Empty task statuses");
       }
       String error = null;
       if (StringUtils.isNotBlank(errorMsg)) {
@@ -619,7 +618,7 @@ public class HiveDriver implements LensDriver {
       context.getDriverStatus().setDriverStartTime(opStatus.getOperationStarted());
       context.getDriverStatus().setDriverFinishTime(opStatus.getOperationCompleted());
     } catch (Exception e) {
-      LOG.error("Error getting query status", e);
+      log.error("Error getting query status", e);
       handleHiveServerError(context, e);
       throw new LensException("Error getting query status", e);
     } finally {
@@ -627,7 +626,7 @@ public class HiveDriver implements LensDriver {
         try {
           in.close();
         } catch (IOException e) {
-          e.printStackTrace();
+          log.error("Error closing stream.", e);
         }
       }
     }
@@ -654,7 +653,7 @@ public class HiveDriver implements LensDriver {
    */
   @Override
   public LensResultSet fetchResultSet(QueryContext ctx) throws LensException {
-    LOG.info("FetchResultSet: " + ctx.getQueryHandle());
+    log.info("FetchResultSet: " + ctx.getQueryHandle());
     // This should be applicable only for a async query
     return createResultSet(ctx, false);
   }
@@ -679,10 +678,10 @@ public class HiveDriver implements LensDriver {
     if (handle == null) {
       return;
     }
-    LOG.info("CloseQuery: " + handle);
+    log.info("CloseQuery: " + handle);
     OperationHandle opHandle = hiveHandles.remove(handle);
     if (opHandle != null) {
-      LOG.info("CloseQuery: " + opHandle);
+      log.info("CloseQuery: " + opHandle);
       try {
         getClient().closeOperation(opHandle);
       } catch (HiveSQLException e) {
@@ -699,10 +698,10 @@ public class HiveDriver implements LensDriver {
    */
   @Override
   public boolean cancelQuery(QueryHandle handle) throws LensException {
-    LOG.info("CancelQuery: " + handle);
+    log.info("CancelQuery: " + handle);
     OperationHandle hiveHandle = getHiveHandle(handle);
     try {
-      LOG.info("CancelQuery hiveHandle: " + hiveHandle);
+      log.info("CancelQuery hiveHandle: " + hiveHandle);
       getClient().cancelOperation(hiveHandle);
       return true;
     } catch (HiveSQLException e) {
@@ -718,7 +717,7 @@ public class HiveDriver implements LensDriver {
    */
   @Override
   public void close() {
-    LOG.info("CloseDriver");
+    log.info("CloseDriver");
     // Close this driver and release all resources
     sessionLock.lock();
     try {
@@ -727,7 +726,7 @@ public class HiveDriver implements LensDriver {
           getClient().closeSession(lensToHiveSession.get(lensSessionDbKey));
         } catch (Exception e) {
           checkInvalidSession(e);
-          LOG.warn("Error closing session for lens session: " + lensSessionDbKey + ", hive session: "
+          log.warn("Error closing session for lens session: " + lensSessionDbKey + ", hive session: "
               + lensToHiveSession.get(lensSessionDbKey), e);
         }
       }
@@ -756,7 +755,7 @@ public class HiveDriver implements LensDriver {
         } catch (Exception e) {
           throw new LensException(e);
         }
-        LOG.info("New thrift connection " + connectionClass);
+        log.info("New thrift connection " + connectionClass);
       }
       return embeddedConnection.getClient();
     } else {
@@ -774,7 +773,7 @@ public class HiveDriver implements LensDriver {
           connection = new ExpirableConnection(tconn, connectionExpiryTimeout);
           thriftConnExpiryQueue.offer(connection);
           threadConnections.put(connectionKey, connection);
-          LOG.info("New thrift connection " + connectionClass + " for thread:" + Thread.currentThread().getId()
+          log.info("New thrift connection " + connectionClass + " for thread:" + Thread.currentThread().getId()
             + " for user:" + user + " connection ID=" + connection.getConnId());
         } catch (Exception e) {
           throw new LensException(e);
@@ -799,7 +798,7 @@ public class HiveDriver implements LensDriver {
    */
   private LensResultSet createResultSet(QueryContext context, boolean closeAfterFetch) throws LensException {
     OperationHandle op = getHiveHandle(context.getQueryHandle());
-    LOG.info("Creating result set for hiveHandle:" + op);
+    log.info("Creating result set for hiveHandle:" + op);
     try {
       if (context.isDriverPersistent()) {
         return new HivePersistentResultSet(new Path(context.getHdfsoutPath()), op, getClient());
@@ -846,7 +845,7 @@ public class HiveDriver implements LensDriver {
       context.unSetDriverPersistent();
       hiveQuery = context.getSelectedDriverQuery();
     }
-    LOG.info("Hive driver query:" + hiveQuery);
+    log.info("Hive driver query:" + hiveQuery);
     context.setSelectedDriverQuery(hiveQuery);
   }
 
@@ -875,14 +874,14 @@ public class HiveDriver implements LensDriver {
         try {
           hiveSession = getClient().openSession(ctx.getClusterUser(), "");
           lensToHiveSession.put(sessionDbKey, hiveSession);
-          LOG.info("New hive session for user: " + ctx.getClusterUser() + ", lens session: " + sessionDbKey
+          log.info("New hive session for user: " + ctx.getClusterUser() + ", lens session: " + sessionDbKey
             + " hive session handle: " + hiveSession.getHandleIdentifier());
           for (LensEventListener<DriverEvent> eventListener : driverListeners) {
             try {
               eventListener.onEvent(new DriverSessionStarted(System.currentTimeMillis(), this, lensSession, hiveSession
                 .getSessionId().toString()));
             } catch (Exception exc) {
-              LOG.error("Error sending driver start event to listener " + eventListener, exc);
+              log.error("Error sending driver start event to listener " + eventListener, exc);
             }
           }
         } catch (Exception e) {
@@ -969,7 +968,7 @@ public class HiveDriver implements LensDriver {
         }
         error = "timedout";
       } catch (Exception e) {
-        LOG.warn("Error while polling for status", e);
+        log.warn("Error while polling for status", e);
         error = "error polling";
       }
       listener.onError(handle, error);
@@ -1025,9 +1024,9 @@ public class HiveDriver implements LensDriver {
         QueryHandle qhandle = (QueryHandle) in.readObject();
         OperationHandle opHandle = new OperationHandle((TOperationHandle) in.readObject());
         hiveHandles.put(qhandle, opHandle);
-        LOG.debug("Hive driver recovered " + qhandle + ":" + opHandle);
+        log.debug("Hive driver recovered " + qhandle + ":" + opHandle);
       }
-      LOG.info("HiveDriver recovered " + hiveHandles.size() + " queries");
+      log.info("HiveDriver recovered " + hiveHandles.size() + " queries");
       int numSessions = in.readInt();
       for (int i = 0; i < numSessions; i++) {
         String lensId = in.readUTF();
@@ -1035,7 +1034,7 @@ public class HiveDriver implements LensDriver {
           TProtocolVersion.HIVE_CLI_SERVICE_PROTOCOL_V6);
         lensToHiveSession.put(lensId, sHandle);
       }
-      LOG.info("HiveDriver recovered " + lensToHiveSession.size() + " sessions");
+      log.info("HiveDriver recovered " + lensToHiveSession.size() + " sessions");
     }
   }
 
@@ -1052,15 +1051,15 @@ public class HiveDriver implements LensDriver {
       for (Map.Entry<QueryHandle, OperationHandle> entry : hiveHandles.entrySet()) {
         out.writeObject(entry.getKey());
         out.writeObject(entry.getValue().toTOperationHandle());
-        LOG.debug("Hive driver persisted " + entry.getKey() + ":" + entry.getValue());
+        log.debug("Hive driver persisted " + entry.getKey() + ":" + entry.getValue());
       }
-      LOG.info("HiveDriver persisted " + hiveHandles.size() + " queries");
+      log.info("HiveDriver persisted " + hiveHandles.size() + " queries");
       out.writeInt(lensToHiveSession.size());
       for (Map.Entry<String, SessionHandle> entry : lensToHiveSession.entrySet()) {
         out.writeUTF(entry.getKey());
         out.writeObject(entry.getValue().toTSessionHandle());
       }
-      LOG.info("HiveDriver persisted " + lensToHiveSession.size() + " sessions");
+      log.info("HiveDriver persisted " + lensToHiveSession.size() + " sessions");
     }
   }
 
@@ -1122,14 +1121,14 @@ public class HiveDriver implements LensDriver {
     for (SessionHandle session : hiveSessionsToCheck) {
       if (isSessionInvalid(exc, session)) {
         // We have to expire previous session
-        LOG.info("Hive server session " + session + " for lens session " + lensSession + " has become invalid");
+        log.info("Hive server session " + session + " for lens session " + lensSession + " has become invalid");
         sessionLock.lock();
         try {
           // We should close all connections and clear the session map since
           // most likely all sessions are gone
           closeAllConnections();
           lensToHiveSession.clear();
-          LOG.info("Cleared all sessions");
+          log.info("Cleared all sessions");
         } finally {
           sessionLock.unlock();
         }
@@ -1146,12 +1145,12 @@ public class HiveDriver implements LensDriver {
   protected void checkInvalidOperation(QueryHandle queryHandle, HiveSQLException exc) {
     final OperationHandle operation = hiveHandles.get(queryHandle);
     if (operation == null) {
-      LOG.info("No hive operation available for " + queryHandle);
+      log.info("No hive operation available for " + queryHandle);
       return;
     }
     if (exc.getMessage() != null && exc.getMessage().contains("Invalid OperationHandle:")
       && exc.getMessage().contains(operation.toString())) {
-      LOG.info("Hive operation " + operation + " for query " + queryHandle + " has become invalid");
+      log.info("Hive operation " + operation + " for query " + queryHandle + " has become invalid");
       hiveHandles.remove(queryHandle);
       return;
     }
@@ -1193,10 +1192,10 @@ public class HiveDriver implements LensDriver {
           if (hiveSession != null) {
             try {
               getClient().closeSession(hiveSession);
-              LOG.info("Closed Hive session " + hiveSession.getHandleIdentifier() + " for lens session "
+              log.info("Closed Hive session " + hiveSession.getHandleIdentifier() + " for lens session "
                 + sessionDbKey);
             } catch (Exception e) {
-              LOG.error("Error closing hive session " + hiveSession.getHandleIdentifier()
+              log.error("Error closing hive session " + hiveSession.getHandleIdentifier()
                 + " for lens session " + sessionDbKey, e);
             }
             resourcesAddedForSession.remove(hiveSession);
@@ -1217,7 +1216,7 @@ public class HiveDriver implements LensDriver {
         try {
           connection.getConnection().close();
         } catch (Exception ce) {
-          LOG.warn("Error closing connection to hive server");
+          log.warn("Error closing connection to hive server");
         }
       }
       threadConnections.clear();

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveInMemoryResultSet.java
----------------------------------------------------------------------
diff --git a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveInMemoryResultSet.java b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveInMemoryResultSet.java
index 4d631ec..3d1f20a 100644
--- a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveInMemoryResultSet.java
+++ b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveInMemoryResultSet.java
@@ -30,9 +30,12 @@ import org.apache.lens.server.api.error.LensException;
 
 import org.apache.hive.service.cli.*;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class HiveInMemoryResultSet.
  */
+@Slf4j
 public class HiveInMemoryResultSet extends InMemoryResultSet {
 
   /** The client. */
@@ -120,7 +123,7 @@ public class HiveInMemoryResultSet extends InMemoryResultSet {
         noMoreResults = rowSet.numRows() == 0;
         if (noMoreResults) {
           if (closeAfterFecth) {
-            HiveDriver.LOG.info("No more results closing the query");
+            log.info("No more results closing the query");
             client.closeOperation(opHandle);
           }
           return false;

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveQueryPlan.java
----------------------------------------------------------------------
diff --git a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveQueryPlan.java b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveQueryPlan.java
index 9d43fa8..b0a04df 100644
--- a/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveQueryPlan.java
+++ b/lens-driver-hive/src/main/java/org/apache/lens/driver/hive/HiveQueryPlan.java
@@ -34,9 +34,12 @@ import org.apache.hadoop.hive.ql.metadata.Hive;
 import org.apache.hadoop.hive.ql.metadata.HiveException;
 import org.apache.hadoop.hive.ql.metadata.Table;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class HiveQueryPlan.
  */
+@Slf4j
 public class HiveQueryPlan extends DriverQueryPlan {
 
   /** The explain output. */
@@ -164,7 +167,7 @@ public class HiveQueryPlan extends DriverQueryPlan {
               Table tbl = metastore.getTable(table, false);
               if (tbl == null) {
                 // table not found, possible case if query is create table
-                HiveDriver.LOG.info("Table " + table + " not found while extracting plan details");
+                log.info("Table " + table + " not found while extracting plan details");
                 continue;
               }
               tablesQueried.add(table);

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-hive/src/test/java/org/apache/lens/driver/hive/TestRemoteHiveDriver.java
----------------------------------------------------------------------
diff --git a/lens-driver-hive/src/test/java/org/apache/lens/driver/hive/TestRemoteHiveDriver.java b/lens-driver-hive/src/test/java/org/apache/lens/driver/hive/TestRemoteHiveDriver.java
index f0566c8..b4086b8 100644
--- a/lens-driver-hive/src/test/java/org/apache/lens/driver/hive/TestRemoteHiveDriver.java
+++ b/lens-driver-hive/src/test/java/org/apache/lens/driver/hive/TestRemoteHiveDriver.java
@@ -35,8 +35,6 @@ import org.apache.lens.server.api.error.LensException;
 import org.apache.lens.server.api.query.QueryContext;
 
 import org.apache.commons.io.FileUtils;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hive.conf.HiveConf;
 import org.apache.hadoop.hive.ql.session.SessionState;
 import org.apache.hive.service.Service;
@@ -47,14 +45,14 @@ import org.testng.annotations.AfterClass;
 import org.testng.annotations.BeforeClass;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestRemoteHiveDriver.
  */
+@Slf4j
 public class TestRemoteHiveDriver extends TestHiveDriver {
 
-  /** The Constant LOG. */
-  public static final Log LOG = LogFactory.getLog(TestRemoteHiveDriver.class);
-
   /** The Constant HS2_HOST. */
   static final String HS2_HOST = "localhost";
 
@@ -121,7 +119,7 @@ public class TestRemoteHiveDriver extends TestHiveDriver {
     try {
       server.stop();
     } catch (Exception e) {
-      e.printStackTrace();
+      log.error("Error stopping hive service", e);
     }
   }
 
@@ -151,7 +149,7 @@ public class TestRemoteHiveDriver extends TestHiveDriver {
    */
   @Test
   public void testMultiThreadClient() throws Exception {
-    LOG.info("@@ Starting multi thread test");
+    log.info("@@ Starting multi thread test");
     // Launch two threads
     createTestTable("test_multithreads");
     HiveConf thConf = new HiveConf(conf, TestRemoteHiveDriver.class);
@@ -175,10 +173,10 @@ public class TestRemoteHiveDriver extends TestHiveDriver {
         thrDriver.executeAsync(qctx);
       } catch (LensException e) {
         errCount.incrementAndGet();
-        LOG.info(q + " executeAsync error: " + e.getCause());
+        log.info(q + " executeAsync error: " + e.getCause());
         continue;
       }
-      LOG.info("@@ Launched query: " + q + " " + qctx.getQueryHandle());
+      log.info("@@ Launched query: " + q + " " + qctx.getQueryHandle());
       launchedQueries++;
       // Launch many threads to poll for status
       final QueryHandle handle = qctx.getQueryHandle();
@@ -192,18 +190,17 @@ public class TestRemoteHiveDriver extends TestHiveDriver {
               try {
                 thrDriver.updateStatus(qctx);
                 if (qctx.getDriverStatus().isFinished()) {
-                  LOG.info("@@ " + handle.getHandleId() + " >> " + qctx.getDriverStatus().getState());
+                  log.info("@@ " + handle.getHandleId() + " >> " + qctx.getDriverStatus().getState());
                   thrDriver.closeQuery(handle);
                   break;
                 }
                 Thread.sleep(POLL_DELAY);
               } catch (LensException e) {
-                LOG.error("Got Exception", e.getCause());
-                e.printStackTrace();
+                log.error("Got Exception " +e.getCause(), e);
                 errCount.incrementAndGet();
                 break;
               } catch (InterruptedException e) {
-                e.printStackTrace();
+                log.error("Encountred Interrupted exception", e);
                 break;
               }
             }
@@ -219,11 +216,11 @@ public class TestRemoteHiveDriver extends TestHiveDriver {
       try {
         th.join(10000);
       } catch (InterruptedException e) {
-        LOG.warn("Not ended yet: " + th.getName());
+        log.warn("Not ended yet: " + th.getName());
       }
     }
     Assert.assertEquals(0, thrDriver.getHiveHandleSize());
-    LOG.info("@@ Completed all pollers. Total thrift errors: " + errCount.get());
+    log.info("@@ Completed all pollers. Total thrift errors: " + errCount.get());
     assertEquals(launchedQueries, QUERIES);
     assertEquals(thrs.size(), QUERIES * THREADS);
     assertEquals(errCount.get(), 0);

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestColumnarSQLRewriter.java
----------------------------------------------------------------------
diff --git a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestColumnarSQLRewriter.java b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestColumnarSQLRewriter.java
index dc30bb9..556ca2c 100644
--- a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestColumnarSQLRewriter.java
+++ b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestColumnarSQLRewriter.java
@@ -46,9 +46,12 @@ import org.testng.annotations.AfterTest;
 import org.testng.annotations.BeforeTest;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestColumnarSQLRewriter.
  */
+@Slf4j
 public class TestColumnarSQLRewriter {
 
   HiveConf hconf = new HiveConf();
@@ -186,7 +189,7 @@ public class TestColumnarSQLRewriter {
       createHiveTable("default", "branch_dim", branchdimColumns);
       createHiveTable("default", "location_dim", locationdimColumns);
     } catch (HiveException e) {
-      e.printStackTrace();
+      log.error("Encountered hive exception.", e);
     }
   }
 
@@ -204,7 +207,7 @@ public class TestColumnarSQLRewriter {
       Hive.get().dropTable("default.branch_dim");
       Hive.get().dropTable("default.location_dim");
     } catch (HiveException e) {
-      e.printStackTrace();
+      log.error("Encountered hive exception", e);
     }
   }
 

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestDataSourceConnectionProvider.java
----------------------------------------------------------------------
diff --git a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestDataSourceConnectionProvider.java b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestDataSourceConnectionProvider.java
index e526700..21e5f50 100644
--- a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestDataSourceConnectionProvider.java
+++ b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestDataSourceConnectionProvider.java
@@ -28,19 +28,18 @@ import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.apache.hadoop.conf.Configuration;
-import org.apache.log4j.Logger;
 
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestDataSourceConnectionProvider.
  */
+@Slf4j
 public class TestDataSourceConnectionProvider {
 
-  /** The Constant LOG. */
-  public static final Logger LOG = Logger.getLogger(TestDataSourceConnectionProvider.class);
-
   /**
    * Test get connection hsql.
    *
@@ -75,20 +74,20 @@ public class TestDataSourceConnectionProvider {
             Assert.assertNotNull(st);
             passed.incrementAndGet();
           } catch (SQLException e) {
-            LOG.error("error getting connection to db!", e);
+            log.error("error getting connection to db!", e);
           } finally {
             if (st != null) {
               try {
                 st.close();
               } catch (SQLException e) {
-                e.printStackTrace();
+                log.error("Encountered SQL ecxception", e);
               }
             }
             if (conn != null) {
               try {
                 conn.close();
               } catch (SQLException e) {
-                e.printStackTrace();
+                log.error("Encountered SQL exception", e);
               }
             }
           }
@@ -134,7 +133,7 @@ public class TestDataSourceConnectionProvider {
         }
       } catch (SQLException sqlEx) {
         if (i != MAX_CONNECTIONS) {
-          LOG.error("Unexpected getConnection error", sqlEx);
+          log.error("Unexpected getConnection error", sqlEx);
         }
         assertEquals(i, MAX_CONNECTIONS, "Failed before last getConnection call: " + sqlEx.getMessage());
       }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java
----------------------------------------------------------------------
diff --git a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java
index 75c428a..4f03f23 100644
--- a/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java
+++ b/lens-driver-jdbc/src/test/java/org/apache/lens/driver/jdbc/TestJdbcDriver.java
@@ -46,8 +46,6 @@ import org.apache.lens.server.api.query.PreparedQueryContext;
 import org.apache.lens.server.api.query.QueryContext;
 import org.apache.lens.server.api.util.LensUtil;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hive.conf.HiveConf;
 import org.apache.hadoop.hive.ql.session.SessionState;
@@ -62,11 +60,13 @@ import org.testng.annotations.Test;
 import com.codahale.metrics.MetricRegistry;
 import com.mchange.v2.c3p0.ComboPooledDataSource;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * The Class TestJdbcDriver.
  */
+@Slf4j
 public class TestJdbcDriver {
-  public static final Log LOG = LogFactory.getLog(TestJdbcDriver.class);
 
   /** The base conf. */
   Configuration baseConf;
@@ -211,7 +211,7 @@ public class TestJdbcDriver {
     try {
       driver.rewriteQuery(createQueryContext(query));
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Error running DDL query.", e);
       th = e;
     }
     Assert.assertNotNull(th);
@@ -222,7 +222,7 @@ public class TestJdbcDriver {
     try {
       driver.rewriteQuery(createQueryContext(query));
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Error running DDL query", e);
       th = e;
     }
     Assert.assertNotNull(th);
@@ -233,7 +233,7 @@ public class TestJdbcDriver {
     try {
       driver.rewriteQuery(createQueryContext(query));
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Error running DDL query", e);
       th = e;
     }
     Assert.assertNotNull(th);
@@ -244,7 +244,7 @@ public class TestJdbcDriver {
     try {
       driver.rewriteQuery(createQueryContext(query));
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Error running DDL query", e);
       th = e;
     }
     Assert.assertNotNull(th);
@@ -272,7 +272,7 @@ public class TestJdbcDriver {
       driver.getEstimateConnectionConf().getInt(JDBCDriverConfConstants.JDBC_POOL_MAX_SIZE, 50);
     for (int i = 0; i < maxEstimateConnections + 10; i++) {
       try {
-        LOG.info("Iteration#" + (i + 1));
+        log.info("Iteration#" + (i + 1));
         String query = i > maxEstimateConnections ? "SELECT * FROM estimate_test" : "CREATE TABLE FOO(ID INT)";
         ExplainQueryContext context = createExplainContext(query, baseConf);
         cost = driver.estimate(context);
@@ -578,8 +578,8 @@ public class TestJdbcDriver {
     try {
       listenerNotificationLatch.await(1, TimeUnit.SECONDS);
     } catch (Exception e) {
-      fail("query completion listener was not notified - " + e.getMessage());
-      e.printStackTrace();
+      fail("Query completion listener was not notified - " + e.getMessage());
+      log.error("Query completion listener was not notified.", e);
     }
 
     LensResultSet grs = driver.fetchResultSet(context);
@@ -738,7 +738,7 @@ public class TestJdbcDriver {
       LensResultSet rs = driver.execute(ctx);
       fail("Should have thrown exception");
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Encountered Lens exception.", e);
     }
 
     final CountDownLatch listenerNotificationLatch = new CountDownLatch(1);
@@ -778,7 +778,7 @@ public class TestJdbcDriver {
       driver.fetchResultSet(ctx);
       fail("should have thrown error");
     } catch (LensException e) {
-      e.printStackTrace();
+      log.error("Encountered Lens exception", e);
     }
     driver.closeQuery(handle);
   }
@@ -816,8 +816,8 @@ public class TestJdbcDriver {
     DataSourceConnectionProvider.DriverConfig queryCfg =
       queryCp.getDriverConfigfromConf(driver.getConf());
 
-    LOG.info("@@@ ESTIMATE_CFG " + estimateCfg);
-    LOG.info("@@@ QUERY CFG " + queryCfg);
+    log.info("@@@ ESTIMATE_CFG " + estimateCfg);
+    log.info("@@@ QUERY CFG " + queryCfg);
 
     // Get connection from each so that pools get initialized
     try {
@@ -825,14 +825,14 @@ public class TestJdbcDriver {
       estimateConn.close();
     } catch (SQLException e) {
       // Ignore exception
-      LOG.error("Error getting connection from estimate pool", e);
+      log.error("Error getting connection from estimate pool", e);
     }
 
     try {
       Connection queryConn = queryCp.getConnection(driver.getConf());
       queryConn.close();
     } catch (SQLException e) {
-      LOG.error("Error getting connection from query pool", e);
+      log.error("Error getting connection from query pool", e);
     }
 
 

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-examples/src/main/java/org/apache/lens/examples/SampleMetastore.java
----------------------------------------------------------------------
diff --git a/lens-examples/src/main/java/org/apache/lens/examples/SampleMetastore.java b/lens-examples/src/main/java/org/apache/lens/examples/SampleMetastore.java
index 2f28e5d..dee43ef 100644
--- a/lens-examples/src/main/java/org/apache/lens/examples/SampleMetastore.java
+++ b/lens-examples/src/main/java/org/apache/lens/examples/SampleMetastore.java
@@ -31,7 +31,11 @@ import org.apache.lens.api.metastore.ObjectFactory;
 import org.apache.lens.client.LensClientSingletonWrapper;
 import org.apache.lens.client.LensMetadataClient;
 
+import lombok.extern.slf4j.Slf4j;
+
+@Slf4j
 public class SampleMetastore {
+
   private LensMetadataClient metaClient;
   public static final Unmarshaller JAXB_UNMARSHALLER;
   private APIResult result;
@@ -117,7 +121,7 @@ public class SampleMetastore {
       System.out.println("Created DB storages");
     } catch (Exception e) {
       retCode = 1;
-      e.printStackTrace();
+      log.error("Creating DB storage failed", e);
       System.err.println("Creating DB storage failed");
     }
   }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-ml-lib/src/main/java/org/apache/lens/client/LensMLClient.java
----------------------------------------------------------------------
diff --git a/lens-ml-lib/src/main/java/org/apache/lens/client/LensMLClient.java b/lens-ml-lib/src/main/java/org/apache/lens/client/LensMLClient.java
index 8ffe853..6dd0ecf 100644
--- a/lens-ml-lib/src/main/java/org/apache/lens/client/LensMLClient.java
+++ b/lens-ml-lib/src/main/java/org/apache/lens/client/LensMLClient.java
@@ -40,16 +40,17 @@ import org.apache.lens.ml.api.TestReport;
 import org.apache.lens.server.api.error.LensException;
 
 import org.apache.commons.lang.StringUtils;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
+
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 
+import lombok.extern.slf4j.Slf4j;
+
 /**
  * Client side implementation of LensML
  */
+@Slf4j
 public class LensMLClient implements LensML, Closeable {
-  private static final Log LOG = LogFactory.getLog(LensMLClient.class);
 
   /** The client. */
   private LensMLJerseyClient client;
@@ -179,7 +180,7 @@ public class LensMLClient implements LensML, Closeable {
         try {
           in.close();
         } catch (IOException e) {
-          e.printStackTrace();
+          log.error("Error closing stream.", e);
         }
       }
     }

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-ml-lib/src/main/java/org/apache/lens/ml/algo/lib/AlgoArgParser.java
----------------------------------------------------------------------
diff --git a/lens-ml-lib/src/main/java/org/apache/lens/ml/algo/lib/AlgoArgParser.java b/lens-ml-lib/src/main/java/org/apache/lens/ml/algo/lib/AlgoArgParser.java
index 51979d8..00f20fc 100644
--- a/lens-ml-lib/src/main/java/org/apache/lens/ml/algo/lib/AlgoArgParser.java
+++ b/lens-ml-lib/src/main/java/org/apache/lens/ml/algo/lib/AlgoArgParser.java
@@ -27,12 +27,12 @@ import java.util.Map;
 import org.apache.lens.ml.algo.api.AlgoParam;
 import org.apache.lens.ml.algo.api.MLAlgo;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * The Class AlgoArgParser.
  */
+@Slf4j
 public final class AlgoArgParser {
   private AlgoArgParser() {
   }
@@ -53,9 +53,6 @@ public final class AlgoArgParser {
     public abstract E parse(String value);
   }
 
-  /** The Constant LOG. */
-  public static final Log LOG = LogFactory.getLog(AlgoArgParser.class);
-
   /**
    * Extracts feature names. If the algo has any parameters associated with @AlgoParam annotation, those are set
    * as well.
@@ -104,12 +101,12 @@ public final class AlgoArgParser {
               CustomArgParser<?> parser = clz.newInstance();
               f.set(algo, parser.parse(value));
             } else {
-              LOG.warn("Ignored param " + key + "=" + value + " as no parser found");
+              log.warn("Ignored param " + key + "=" + value + " as no parser found");
             }
           }
         }
       } catch (Exception exc) {
-        LOG.error("Error while setting param " + key + " to " + value + " for algo " + algo);
+        log.error("Error while setting param " + key + " to " + value + " for algo " + algo, exc);
       }
     }
     return featureColumns;

http://git-wip-us.apache.org/repos/asf/incubator-lens/blob/b0783db7/lens-ml-lib/src/main/java/org/apache/lens/ml/impl/LensMLImpl.java
----------------------------------------------------------------------
diff --git a/lens-ml-lib/src/main/java/org/apache/lens/ml/impl/LensMLImpl.java b/lens-ml-lib/src/main/java/org/apache/lens/ml/impl/LensMLImpl.java
index e4c03c8..de76603 100644
--- a/lens-ml-lib/src/main/java/org/apache/lens/ml/impl/LensMLImpl.java
+++ b/lens-ml-lib/src/main/java/org/apache/lens/ml/impl/LensMLImpl.java
@@ -52,8 +52,6 @@ import org.apache.lens.server.api.error.LensException;
 import org.apache.lens.server.api.session.SessionService;
 
 import org.apache.commons.io.IOUtils;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -66,15 +64,14 @@ import org.glassfish.jersey.media.multipart.FormDataContentDisposition;
 import org.glassfish.jersey.media.multipart.FormDataMultiPart;
 import org.glassfish.jersey.media.multipart.MultiPartFeature;
 
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * The Class LensMLImpl.
  */
+@Slf4j
 public class LensMLImpl implements LensML {
 
-  /** The Constant LOG. */
-  public static final Log LOG = LogFactory.getLog(LensMLImpl.class);
-
   /** The drivers. */
   protected List<MLDriver> drivers;
 
@@ -144,7 +141,7 @@ public class LensMLImpl implements LensML {
 
     String modelId = UUID.randomUUID().toString();
 
-    LOG.info("Begin training model " + modelId + ", algo=" + algorithm + ", table=" + table + ", params="
+    log.info("Begin training model " + modelId + ", algo=" + algorithm + ", table=" + table + ", params="
       + Arrays.toString(args));
 
     String database = null;
@@ -156,7 +153,7 @@ public class LensMLImpl implements LensML {
 
     MLModel model = algo.train(toLensConf(conf), database, table, modelId, args);
 
-    LOG.info("Done training model: " + modelId);
+    log.info("Done training model: " + modelId);
 
     model.setCreatedAt(new Date());
     model.setAlgoName(algorithm);
@@ -164,7 +161,7 @@ public class LensMLImpl implements LensML {
     Path modelLocation = null;
     try {
       modelLocation = persistModel(model);
-      LOG.info("Model saved: " + modelId + ", algo: " + algorithm + ", path: " + modelLocation);
+      log.info("Model saved: " + modelId + ", algo: " + algorithm + ", path: " + modelLocation);
       return model.getId();
     } catch (IOException e) {
       throw new LensException("Error saving model " + modelId + " for algo " + algorithm, e);
@@ -207,7 +204,7 @@ public class LensMLImpl implements LensML {
       outputStream.writeObject(model);
       outputStream.flush();
     } catch (IOException io) {
-      LOG.error("Error saving model " + model.getId() + " reason: " + io.getMessage());
+      log.error("Error saving model " + model.getId() + " reason: " + io.getMessage(), io);
       throw io;
     } finally {
       IOUtils.closeQuietly(outputStream);
@@ -272,7 +269,7 @@ public class LensMLImpl implements LensML {
       throw new RuntimeException("No ML Drivers specified in conf");
     }
 
-    LOG.info("Loading drivers " + Arrays.toString(driverClasses));
+    log.info("Loading drivers " + Arrays.toString(driverClasses));
     drivers = new ArrayList<MLDriver>(driverClasses.length);
 
     for (String driverClass : driverClasses) {
@@ -280,12 +277,12 @@ public class LensMLImpl implements LensML {
       try {
         cls = Class.forName(driverClass);
       } catch (ClassNotFoundException e) {
-        LOG.error("Driver class not found " + driverClass);
+        log.error("Driver class not found " + driverClass, e);
         continue;
       }
 
       if (!MLDriver.class.isAssignableFrom(cls)) {
-        LOG.warn("Not a driver class " + driverClass);
+        log.warn("Not a driver class " + driverClass);
         continue;
       }
 
@@ -294,16 +291,16 @@ public class LensMLImpl implements LensML {
         MLDriver driver = mlDriverClass.newInstance();
         driver.init(toLensConf(conf));
         drivers.add(driver);
-        LOG.info("Added driver " + driverClass);
+        log.info("Added driver " + driverClass);
       } catch (Exception e) {
-        LOG.error("Failed to create driver " + driverClass + " reason: " + e.getMessage(), e);
+        log.error("Failed to create driver " + driverClass + " reason: " + e.getMessage(), e);
       }
     }
     if (drivers.isEmpty()) {
       throw new RuntimeException("No ML drivers loaded");
     }
 
-    LOG.info("Inited ML service");
+    log.info("Inited ML service");
   }
 
   /**
@@ -317,14 +314,14 @@ public class LensMLImpl implements LensML {
         }
         driver.start();
       } catch (LensException e) {
-        LOG.error("Failed to start driver " + driver, e);
+        log.error("Failed to start driver " + driver, e);
       }
     }
 
     udfStatusExpirySvc = Executors.newSingleThreadScheduledExecutor();
     udfStatusExpirySvc.scheduleAtFixedRate(new UDFStatusExpiryRunnable(), 60, 60, TimeUnit.SECONDS);
 
-    LOG.info("Started ML service");
+    log.info("Started ML service");
   }
 
   /**
@@ -335,12 +332,12 @@ public class LensMLImpl implements LensML {
       try {
         driver.stop();
       } catch (LensException e) {
-        LOG.error("Failed to stop driver " + driver, e);
+        log.error("Failed to stop driver " + driver, e);
       }
     }
     drivers.clear();
     udfStatusExpirySvc.shutdownNow();
-    LOG.info("Stopped ML service");
+    log.info("Stopped ML service");
   }
 
   public synchronized HiveConf getHiveConf() {
@@ -455,18 +452,18 @@ public class LensMLImpl implements LensML {
     }
 
     if (!spec.isOutputTableExists()) {
-      LOG.info("Output table '" + testTable + "' does not exist for test algorithm = " + algorithm + " modelid="
+      log.info("Output table '" + testTable + "' does not exist for test algorithm = " + algorithm + " modelid="
         + modelID + ", Creating table using query: " + spec.getCreateOutputTableQuery());
       // create the output table
       String createOutputTableQuery = spec.getCreateOutputTableQuery();
       queryRunner.runQuery(createOutputTableQuery);
-      LOG.info("Table created " + testTable);
+      log.info("Table created " + testTable);
     }
 
     // Check if ML UDF is registered in this session
     registerPredictUdf(sessionHandle, queryRunner);
 
-    LOG.info("Running evaluation query " + testQuery);
+    log.info("Running evaluation query " + testQuery);
     queryRunner.setQueryName("model_test_" + modelID);
     QueryHandle testQueryHandle = queryRunner.runQuery(testQuery);
 
@@ -483,7 +480,7 @@ public class LensMLImpl implements LensML {
 
     // Save test report
     persistTestReport(testReport);
-    LOG.info("Saved test report " + testReport.getReportID());
+    log.info("Saved test report " + testReport.getReportID());
     return testReport;
   }
 
@@ -494,12 +491,12 @@ public class LensMLImpl implements LensML {
    * @throws LensException the lens exception
    */
   private void persistTestReport(MLTestReport testReport) throws LensException {
-    LOG.info("saving test report " + testReport.getReportID());
+    log.info("saving test report " + testReport.getReportID());
     try {
       ModelLoader.saveTestReport(conf, testReport);
-      LOG.info("Saved report " + testReport.getReportID());
+      log.info("Saved report " + testReport.getReportID());
     } catch (IOException e) {
-      LOG.error("Error saving report " + testReport.getReportID() + " reason: " + e.getMessage());
+      log.error("Error saving report " + testReport.getReportID() + " reason: " + e.getMessage(), e);
     }
   }
 
@@ -529,7 +526,7 @@ public class LensMLImpl implements LensML {
       }
       return reports;
     } catch (IOException e) {
-      LOG.error("Error reading report list for " + algorithm, e);
+      log.error("Error reading report list for " + algorithm, e);
       return null;
     }
   }
@@ -566,9 +563,9 @@ public class LensMLImpl implements LensML {
   public void deleteModel(String algorithm, String modelID) throws LensException {
     try {
       ModelLoader.deleteModel(conf, algorithm, modelID);
-      LOG.info("DELETED model " + modelID + " algorithm=" + algorithm);
+      log.info("DELETED model " + modelID + " algorithm=" + algorithm);
     } catch (IOException e) {
-      LOG.error(
+      log.error(
         "Error deleting model file. algorithm=" + algorithm + " model=" + modelID + " reason: " + e.getMessage(), e);
       throw new LensException("Unable to delete model " + modelID + " for algorithm " + algorithm, e);
     }
@@ -582,9 +579,9 @@ public class LensMLImpl implements LensML {
   public void deleteTestReport(String algorithm, String reportID) throws LensException {
     try {
       ModelLoader.deleteTestReport(conf, algorithm, reportID);
-      LOG.info("DELETED report=" + reportID + " algorithm=" + algorithm);
+      log.info("DELETED report=" + reportID + " algorithm=" + algorithm);
     } catch (IOException e) {
-      LOG.error("Error deleting report " + reportID + " algorithm=" + algorithm + " reason: " + e.getMessage(), e);
+      log.error("Error deleting report " + reportID + " algorithm=" + algorithm + " reason: " + e.getMessage(), e);
       throw new LensException("Unable to delete report " + reportID + " for algorithm " + algorithm, e);
     }
   }
@@ -599,7 +596,7 @@ public class LensMLImpl implements LensML {
     try {
       algo = getAlgoForName(algorithm);
     } catch (LensException e) {
-      LOG.error("Error getting algo description : " + algorithm, e);
+      log.error("Error getting algo description : " + algorithm, e);
       return null;
     }
     if (algo instanceof BaseSparkAlgo) {
@@ -693,15 +690,15 @@ public class LensMLImpl implements LensML {
       return;
     }
 
-    LOG.info("Registering UDF for session " + sessionHandle.getPublicId().toString());
+    log.info("Registering UDF for session " + sessionHandle.getPublicId().toString());
 
     String regUdfQuery = "CREATE TEMPORARY FUNCTION " + HiveMLUDF.UDF_NAME + " AS '" + HiveMLUDF.class
       .getCanonicalName() + "'";
     queryRunner.setQueryName("register_predict_udf_" + sessionHandle.getPublicId().toString());
     QueryHandle udfQuery = queryRunner.runQuery(regUdfQuery);
-    LOG.info("udf query handle is " + udfQuery);
+    log.info("udf query handle is " + udfQuery);
     predictUdfStatus.put(sessionHandle, true);
-    LOG.info("Predict UDF registered for session " + sessionHandle.getPublicId().toString());
+    log.info("Predict UDF registered for session " + sessionHandle.getPublicId().toString());
   }
 
   protected boolean isUdfRegisterd(LensSessionHandle sessionHandle) {
@@ -719,12 +716,12 @@ public class LensMLImpl implements LensML {
         List<LensSessionHandle> sessions = new ArrayList<LensSessionHandle>(predictUdfStatus.keySet());
         for (LensSessionHandle sessionHandle : sessions) {
           if (!sessionService.isOpen(sessionHandle)) {
-            LOG.info("Session closed, removing UDF status: " + sessionHandle);
+            log.info("Session closed, removing UDF status: " + sessionHandle);
             predictUdfStatus.remove(sessionHandle);
           }
         }
       } catch (Exception exc) {
-        LOG.warn("Error clearing UDF statuses", exc);
+        log.warn("Error clearing UDF statuses", exc);
       }
     }
   }