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. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
