suneet-s commented on a change in pull request #10359: URL: https://github.com/apache/druid/pull/10359#discussion_r502023182
########## File path: indexing-service/src/main/java/org/apache/druid/indexing/worker/shuffle/ShuffleModule.java ########## @@ -0,0 +1,60 @@ +/* + * 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.druid.indexing.worker.shuffle; + +import com.google.inject.Binder; +import com.google.inject.Module; +import com.google.inject.Provides; +import org.apache.druid.guice.Jerseys; +import org.apache.druid.guice.LazySingleton; +import org.apache.druid.java.util.metrics.MonitorScheduler; + +import java.util.Optional; + +public class ShuffleModule implements Module +{ + @Override + public void configure(Binder binder) + { + Jerseys.addResource(binder, ShuffleResource.class); + } + + /** + * {@link ShuffleMetrics} is used in {@link ShuffleResource} and {@link ShuffleMonitor} to collect metrics + * and report them, respectively. Unlike ShuffleResource, ShuffleMonitor can be created via a user config + * ({@link org.apache.druid.server.metrics.MonitorsConfig}) in potentially any node types, where it is not + * possible to create ShuffleMetrics. This method checks the {@link MonitorScheduler} if ShuffleMonitor is + * registered on it, and sets the proper ShuffleMetrics. + */ + @Provides + @LazySingleton + public Optional<ShuffleMetrics> getShuffleMetrics(MonitorScheduler monitorScheduler) + { + // ShuffleMonitor cannot be registered dynamically, but can only via the static configuration (MonitorsConfig). + // As a result, it is safe to check only one time if it is registered in MonitorScheduler. + final Optional<ShuffleMonitor> maybeMonitor = monitorScheduler.findMonitor(ShuffleMonitor.class); Review comment: I see that `MonitorScheduler` has a `removeMonitor` method, and ShuffleMetrics is provided as a Singleton. Can someone remove the ShuffleMonitor while Druid is running? If they do that how would it impact ShuffleMetrics being reported ---------------------------------------------------------------- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
