tillrohrmann commented on a change in pull request #17485: URL: https://github.com/apache/flink/pull/17485#discussion_r791527216
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/highavailability/zookeeper/ZooKeeperMultipleComponentLeaderElectionHaServices.java ########## @@ -0,0 +1,179 @@ +/* + * 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.flink.runtime.highavailability.zookeeper; + +import org.apache.flink.api.common.JobID; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.runtime.blob.BlobStoreService; +import org.apache.flink.runtime.leaderelection.DefaultLeaderElectionService; +import org.apache.flink.runtime.leaderelection.DefaultMultipleComponentLeaderElectionService; +import org.apache.flink.runtime.leaderelection.LeaderElectionService; +import org.apache.flink.runtime.leaderelection.MultipleComponentLeaderElectionService; +import org.apache.flink.runtime.leaderelection.ZooKeeperMultipleComponentLeaderElectionDriverFactory; +import org.apache.flink.runtime.leaderretrieval.LeaderRetrievalService; +import org.apache.flink.runtime.rpc.FatalErrorHandler; +import org.apache.flink.runtime.util.ZooKeeperUtils; +import org.apache.flink.util.ExceptionUtils; +import org.apache.flink.util.FlinkRuntimeException; + +import org.apache.flink.shaded.curator4.org.apache.curator.framework.CuratorFramework; + +import javax.annotation.Nullable; +import javax.annotation.concurrent.GuardedBy; + +import java.util.concurrent.Executor; + +/** + * ZooKeeper HA services that only use a single leader election per process. + * + * <pre> + * /flink + * +/cluster_id_1/leader/latch + * | | /resource_manager/connection_info + * | | /dispatcher/connection_info + * | | /rest_server/connection_info + * | | /job-id-1/connection_info + * | | /job-id-2/connection_info + * | | + * | | + * | +jobgraphs/job-id-1 + * | | /job-id-2 + * | +jobs/job-id-1/checkpoints/latest + * | | /latest-1 + * | | /latest-2 + * | | /checkpoint_id_counter + * </pre> + */ +public class ZooKeeperMultipleComponentLeaderElectionHaServices + extends AbstractZooKeeperHaServices { + + private final Object lock = new Object(); + + private final CuratorFramework leaderNamespacedCuratorFramework; + + private final FatalErrorHandler fatalErrorHandler; + + @Nullable + @GuardedBy("lock") + private MultipleComponentLeaderElectionService multipleComponentLeaderElectionService = null; + + public ZooKeeperMultipleComponentLeaderElectionHaServices( + CuratorFrameworkWithUnhandledErrorListener curatorFrameworkWrapper, + Configuration config, + Executor ioExecutor, + BlobStoreService blobStoreService, + FatalErrorHandler fatalErrorHandler) + throws Exception { + super(curatorFrameworkWrapper, ioExecutor, config, blobStoreService); + this.leaderNamespacedCuratorFramework = + ZooKeeperUtils.useNamespaceAndEnsurePath( + getCuratorFramework(), ZooKeeperUtils.getLeaderPath()); + this.fatalErrorHandler = fatalErrorHandler; + } + + @Override + protected LeaderElectionService createLeaderElectionService(String leaderName) { + final MultipleComponentLeaderElectionService multipleComponentLeaderElectionService; + + synchronized (lock) { + multipleComponentLeaderElectionService = getOrInitializeSingleLeaderElectionService(); + } + + return new DefaultLeaderElectionService( + multipleComponentLeaderElectionService.createDriverFactory(leaderName)); + } + + @GuardedBy("lock") + private MultipleComponentLeaderElectionService getOrInitializeSingleLeaderElectionService() { + if (multipleComponentLeaderElectionService == null) { + try { + multipleComponentLeaderElectionService = + new DefaultMultipleComponentLeaderElectionService( + fatalErrorHandler, + "Single leader election service.", + new ZooKeeperMultipleComponentLeaderElectionDriverFactory( + leaderNamespacedCuratorFramework)); + } catch (Exception e) { + throw new FlinkRuntimeException( + String.format( + "Could not initialize the %s", + DefaultMultipleComponentLeaderElectionService.class + .getSimpleName()), + e); + } + } + + return multipleComponentLeaderElectionService; + } + + @Override + protected LeaderRetrievalService createLeaderRetrievalService(String leaderPath) { + // Maybe use a single service for leader retrieval + return ZooKeeperUtils.createLeaderRetrievalService( + leaderNamespacedCuratorFramework, leaderPath, configuration); + } + + @Override + protected void internalClose() throws Exception { + Exception exception = null; + synchronized (lock) { + if (multipleComponentLeaderElectionService != null) { + try { + multipleComponentLeaderElectionService.close(); + } catch (Exception e) { + exception = e; + } + multipleComponentLeaderElectionService = null; + } + } + + try { + super.internalClose(); + } catch (Exception e) { + exception = ExceptionUtils.firstOrSuppressed(e, exception); + } + + ExceptionUtils.tryRethrowException(exception); + } + + @Override + protected void internalCleanupJobData(JobID jobID) throws Exception { + super.internalCleanupJobData(jobID); + } + + @Override + protected String getLeaderPathForResourceManager() { + return ZooKeeperUtils.getResourceManagerNode(); + } + + @Override + protected String getLeaderPathForDispatcher() { + return ZooKeeperUtils.getDispatcherNode(); + } + + @Override + protected String getLeaderPathForJobManager(JobID jobID) { + return jobID.toString(); + } + + @Override + protected String getLeaderPathForRestServer() { + return ZooKeeperUtils.getRestServerNode(); + } Review comment: I think you are right that there is a difference between the method name and what is returned. In this case I would suggest to change the naming of the methods to `getLeaderNameXYZ` instead of `getLeaderPathXZY`. -- 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. To unsubscribe, e-mail: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
