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Posted to commits@samza.apache.org by GitBox <gi...@apache.org> on 2021/04/26 23:47:47 UTC
[GitHub] [samza] cameronlee314 opened a new pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
cameronlee314 opened a new pull request #1495:
URL: https://github.com/apache/samza/pull/1495
Issues: In environments without an external metrics system, it is hard to access any metrics. It can be useful to have a MetricsReporter which logs metrics so that they can be accessed somewhere. This can be used to help verify certain flows are working.
Changes: Added `LoggingMetricsReporter` which periodically logs metrics to a log file.
Tests: Deployed a Samza job on my local machine and configured it to use the new reporter. Verified that logs showed some metrics.
API changes and usage/upgrade instructions:
Add a new metrics reporter in the config which uses `org.apache.samza.metrics.reporter.LoggingMetricsReporterFactory`.
Example:
`metrics.reporters=loggingReporter`
`metrics.reporter.loggingReporter.class=org.apache.samza.metrics.reporter.LoggingMetricsReporterFactory`
`metrics.reporter.loggingReporter.log.regex=.*messages-read.*`
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[GitHub] [samza] cameronlee314 commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
cameronlee314 commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r627011501
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
+ private final Pattern metricsToLog;
+ private final long loggingIntervalSeconds;
+ private final Queue<Runnable> loggingTasks = new ConcurrentLinkedQueue<>();
+
+ /**
+ * @param scheduledExecutorService executes the logging tasks
+ * @param metricsToLog Only log the metrics which match this regex. The strings for matching against this metric are
+ * constructed by concatenating source name, group name, and metric name, delimited by dashes.
+ * @param loggingIntervalSeconds interval at which to log metrics
+ */
+ public LoggingMetricsReporter(ScheduledExecutorService scheduledExecutorService, Pattern metricsToLog,
+ long loggingIntervalSeconds) {
+ this.scheduledExecutorService = scheduledExecutorService;
+ this.metricsToLog = metricsToLog;
+ this.loggingIntervalSeconds = loggingIntervalSeconds;
+ }
+
+ @Override
+ public void start() {
+ this.scheduledExecutorService.scheduleAtFixedRate(() -> this.loggingTasks.forEach(Runnable::run),
+ this.loggingIntervalSeconds, this.loggingIntervalSeconds, TimeUnit.SECONDS);
+ }
+
+ @Override
+ public void register(String source, ReadableMetricsRegistry registry) {
+ this.loggingTasks.add(buildLoggingTask(source, registry));
+ }
+
+ @Override
+ public void stop() {
+ this.scheduledExecutorService.shutdown();
+ try {
+ this.scheduledExecutorService.awaitTermination(10, TimeUnit.SECONDS);
+ } catch (InterruptedException e) {
+ LOG.warn("Interrupted while shutting down executor", e);
+ }
+ if (!this.scheduledExecutorService.isTerminated()) {
+ LOG.warn("Unable to shutdown executor");
+ }
+ }
+
+ /**
+ * VisibleForTesting so that the logging call can be verified in unit tests.
+ */
+ @VisibleForTesting
+ void doLog(String logString) {
+ LOG.info(logString);
+ }
+
+ private Runnable buildLoggingTask(String source, ReadableMetricsRegistry registry) {
+ return () -> {
+ for (String group : registry.getGroups()) {
+ for (Map.Entry<String, Metric> metricGroupEntry : registry.getGroup(group).entrySet()) {
+ metricGroupEntry.getValue().visit(new MetricsVisitor() {
+ @Override
+ public void counter(Counter counter) {
+ logMetric(source, group, counter.getName(), counter.getCount());
+ }
+
+ @Override
+ public <T> void gauge(Gauge<T> gauge) {
+ logMetric(source, group, gauge.getName(), gauge.getValue());
+ }
+
+ @Override
+ public void timer(Timer timer) {
+ logMetric(source, group, timer.getName(), timer.getSnapshot().getAverage());
+ }
+ });
+ }
+ }
+ };
+ }
+
+ private <T> void logMetric(String source, String group, String metricName, T value) {
+ String fullMetricName = String.format(FULL_METRIC_FORMAT, source, group, metricName);
+ if (this.metricsToLog.matcher(fullMetricName).matches()) {
+ doLog(String.format("Metric: %s, Value: %s", fullMetricName, value));
Review comment:
I figure that someone could also just grep `LoggingMetricsReporter` anyways, since a tag like `Metric` or `[Metric]` could still catch logs from some other component.
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[GitHub] [samza] rmatharu commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
rmatharu commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r626848578
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
+ private final Pattern metricsToLog;
+ private final long loggingIntervalSeconds;
+ private final Queue<Runnable> loggingTasks = new ConcurrentLinkedQueue<>();
+
+ /**
+ * @param scheduledExecutorService executes the logging tasks
+ * @param metricsToLog Only log the metrics which match this regex. The strings for matching against this metric are
+ * constructed by concatenating source name, group name, and metric name, delimited by dashes.
+ * @param loggingIntervalSeconds interval at which to log metrics
+ */
+ public LoggingMetricsReporter(ScheduledExecutorService scheduledExecutorService, Pattern metricsToLog,
+ long loggingIntervalSeconds) {
+ this.scheduledExecutorService = scheduledExecutorService;
+ this.metricsToLog = metricsToLog;
+ this.loggingIntervalSeconds = loggingIntervalSeconds;
+ }
+
+ @Override
+ public void start() {
+ this.scheduledExecutorService.scheduleAtFixedRate(() -> this.loggingTasks.forEach(Runnable::run),
+ this.loggingIntervalSeconds, this.loggingIntervalSeconds, TimeUnit.SECONDS);
+ }
+
+ @Override
+ public void register(String source, ReadableMetricsRegistry registry) {
+ this.loggingTasks.add(buildLoggingTask(source, registry));
+ }
+
+ @Override
+ public void stop() {
+ this.scheduledExecutorService.shutdown();
+ try {
+ this.scheduledExecutorService.awaitTermination(10, TimeUnit.SECONDS);
+ } catch (InterruptedException e) {
+ LOG.warn("Interrupted while shutting down executor", e);
+ }
+ if (!this.scheduledExecutorService.isTerminated()) {
+ LOG.warn("Unable to shutdown executor");
+ }
+ }
+
+ /**
+ * VisibleForTesting so that the logging call can be verified in unit tests.
+ */
+ @VisibleForTesting
+ void doLog(String logString) {
+ LOG.info(logString);
+ }
+
+ private Runnable buildLoggingTask(String source, ReadableMetricsRegistry registry) {
+ return () -> {
+ for (String group : registry.getGroups()) {
+ for (Map.Entry<String, Metric> metricGroupEntry : registry.getGroup(group).entrySet()) {
+ metricGroupEntry.getValue().visit(new MetricsVisitor() {
+ @Override
+ public void counter(Counter counter) {
+ logMetric(source, group, counter.getName(), counter.getCount());
+ }
+
+ @Override
+ public <T> void gauge(Gauge<T> gauge) {
+ logMetric(source, group, gauge.getName(), gauge.getValue());
+ }
+
+ @Override
+ public void timer(Timer timer) {
+ logMetric(source, group, timer.getName(), timer.getSnapshot().getAverage());
+ }
+ });
+ }
+ }
+ };
+ }
+
+ private <T> void logMetric(String source, String group, String metricName, T value) {
+ String fullMetricName = String.format(FULL_METRIC_FORMAT, source, group, metricName);
+ if (this.metricsToLog.matcher(fullMetricName).matches()) {
+ doLog(String.format("Metric: %s, Value: %s", fullMetricName, value));
Review comment:
would make sense to add a tag, like "[Metric]" to allow easy grep of logs,
although "Metric:" would work as well i guess,.
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[GitHub] [samza] rmatharu commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
rmatharu commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r626848110
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
+ private final Pattern metricsToLog;
+ private final long loggingIntervalSeconds;
+ private final Queue<Runnable> loggingTasks = new ConcurrentLinkedQueue<>();
+
+ /**
+ * @param scheduledExecutorService executes the logging tasks
+ * @param metricsToLog Only log the metrics which match this regex. The strings for matching against this metric are
+ * constructed by concatenating source name, group name, and metric name, delimited by dashes.
+ * @param loggingIntervalSeconds interval at which to log metrics
+ */
+ public LoggingMetricsReporter(ScheduledExecutorService scheduledExecutorService, Pattern metricsToLog,
+ long loggingIntervalSeconds) {
+ this.scheduledExecutorService = scheduledExecutorService;
+ this.metricsToLog = metricsToLog;
+ this.loggingIntervalSeconds = loggingIntervalSeconds;
+ }
+
+ @Override
+ public void start() {
+ this.scheduledExecutorService.scheduleAtFixedRate(() -> this.loggingTasks.forEach(Runnable::run),
Review comment:
Could schedule just one event which runs through all registries and emits their data?
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[GitHub] [samza] cameronlee314 commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
cameronlee314 commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r627009174
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
Review comment:
In general, I like to follow this dependency injection pattern. It gives slightly more flexibility in usage, and it makes mocking easier in tests. Just minor benefits (and they aren't really that helpful in this case) though.
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[GitHub] [samza] rmatharu commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
rmatharu commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r626847257
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
Review comment:
Any reason this shouldnt just be a initialized to Executors.newSingleThreadExecutor();
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[GitHub] [samza] cameronlee314 merged pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
cameronlee314 merged pull request #1495:
URL: https://github.com/apache/samza/pull/1495
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[GitHub] [samza] cameronlee314 commented on a change in pull request #1495: SAMZA-2649: Add MetricsReporter which logs metrics to log file
Posted by GitBox <gi...@apache.org>.
cameronlee314 commented on a change in pull request #1495:
URL: https://github.com/apache/samza/pull/1495#discussion_r627010499
##########
File path: samza-core/src/main/java/org/apache/samza/metrics/reporter/LoggingMetricsReporter.java
##########
@@ -0,0 +1,132 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.samza.metrics.reporter;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.regex.Pattern;
+import com.google.common.annotations.VisibleForTesting;
+import org.apache.samza.metrics.Counter;
+import org.apache.samza.metrics.Gauge;
+import org.apache.samza.metrics.Metric;
+import org.apache.samza.metrics.MetricsReporter;
+import org.apache.samza.metrics.MetricsVisitor;
+import org.apache.samza.metrics.ReadableMetricsRegistry;
+import org.apache.samza.metrics.Timer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+/**
+ * Implementation of {@link MetricsReporter} which logs metrics which match a regex.
+ * The regex is checked against "[source name]-[group name]-[metric name]".
+ */
+public class LoggingMetricsReporter implements MetricsReporter {
+ private static final Logger LOG = LoggerFactory.getLogger(LoggingMetricsReporter.class);
+ /**
+ * First part is source, second part is group name, third part is metric name
+ */
+ private static final String FULL_METRIC_FORMAT = "%s-%s-%s";
+
+ private final ScheduledExecutorService scheduledExecutorService;
+ private final Pattern metricsToLog;
+ private final long loggingIntervalSeconds;
+ private final Queue<Runnable> loggingTasks = new ConcurrentLinkedQueue<>();
+
+ /**
+ * @param scheduledExecutorService executes the logging tasks
+ * @param metricsToLog Only log the metrics which match this regex. The strings for matching against this metric are
+ * constructed by concatenating source name, group name, and metric name, delimited by dashes.
+ * @param loggingIntervalSeconds interval at which to log metrics
+ */
+ public LoggingMetricsReporter(ScheduledExecutorService scheduledExecutorService, Pattern metricsToLog,
+ long loggingIntervalSeconds) {
+ this.scheduledExecutorService = scheduledExecutorService;
+ this.metricsToLog = metricsToLog;
+ this.loggingIntervalSeconds = loggingIntervalSeconds;
+ }
+
+ @Override
+ public void start() {
+ this.scheduledExecutorService.scheduleAtFixedRate(() -> this.loggingTasks.forEach(Runnable::run),
Review comment:
I considered that, but this way allows the code to avoid creating a separate class to hold the pair of registry + source. Everything is already bundled within the `Runnable`. I felt that since this is just logging, there isn't a perf/timing difference, so I slightly preferred the way this impl looks.
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