TisonKun commented on a change in pull request #9832: [FLINK-11843] Bind lifespan of Dispatcher to leader session URL: https://github.com/apache/flink/pull/9832#discussion_r336494274
########## File path: flink-runtime/src/main/java/org/apache/flink/runtime/dispatcher/runner/SessionDispatcherLeaderProcess.java ########## @@ -0,0 +1,283 @@ +/* + * 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.dispatcher.runner; + +import org.apache.flink.api.common.JobID; +import org.apache.flink.runtime.client.DuplicateJobSubmissionException; +import org.apache.flink.runtime.concurrent.FutureUtils; +import org.apache.flink.runtime.dispatcher.Dispatcher; +import org.apache.flink.runtime.dispatcher.DispatcherGateway; +import org.apache.flink.runtime.dispatcher.DispatcherId; +import org.apache.flink.runtime.jobgraph.JobGraph; +import org.apache.flink.runtime.jobmanager.JobGraphStore; +import org.apache.flink.runtime.rpc.FatalErrorHandler; +import org.apache.flink.runtime.rpc.RpcUtils; +import org.apache.flink.util.ExceptionUtils; +import org.apache.flink.util.FlinkRuntimeException; +import org.apache.flink.util.Preconditions; +import org.apache.flink.util.function.FunctionUtils; + +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.Optional; +import java.util.UUID; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.CompletionException; +import java.util.concurrent.Executor; + +/** + * Process which encapsulates the job recovery logic and life cycle management of a + * {@link Dispatcher}. + */ +public class SessionDispatcherLeaderProcess extends AbstractDispatcherLeaderProcess implements JobGraphStore.JobGraphListener { + + private final DispatcherServiceFactory dispatcherFactory; + + private final JobGraphStore jobGraphStore; + + private final Executor ioExecutor; + + private CompletableFuture<Void> onGoingRecoveryOperation = FutureUtils.completedVoidFuture(); + + private SessionDispatcherLeaderProcess( + UUID leaderSessionId, + DispatcherServiceFactory dispatcherFactory, + JobGraphStore jobGraphStore, + Executor ioExecutor, + FatalErrorHandler fatalErrorHandler) { + super(leaderSessionId, fatalErrorHandler); + + this.dispatcherFactory = dispatcherFactory; + this.jobGraphStore = jobGraphStore; + this.ioExecutor = ioExecutor; + } + + @Override + protected void onStart() { + startServices(); + + onGoingRecoveryOperation = recoverJobsAsync() + .thenAccept(this::createDispatcherIfRunning) + .handle(this::onErrorIfRunning); + } + + private void startServices() { + try { + jobGraphStore.start(this); + } catch (Exception e) { + throw new FlinkRuntimeException( + String.format( + "Could not start %s when trying to start the %s.", + jobGraphStore.getClass().getSimpleName(), + getClass().getSimpleName()), + e); + } + } + + private void createDispatcherIfRunning(Collection<JobGraph> jobGraphs) { + runIfStateIs(State.RUNNING, () -> createDispatcher(jobGraphs)); + } + + private void createDispatcher(Collection<JobGraph> jobGraphs) { + + final DispatcherService dispatcherService = dispatcherFactory.create( + DispatcherId.fromUuid(getLeaderSessionId()), + jobGraphs, + jobGraphStore); + + completeDispatcherSetup(dispatcherService); + } + + private CompletableFuture<Collection<JobGraph>> recoverJobsAsync() { + return CompletableFuture.supplyAsync( + this::recoverJobsIfRunning, + ioExecutor); + } + + private Collection<JobGraph> recoverJobsIfRunning() { + return supplyUnsynchronizedIfRunning(this::recoverJobs).orElse(Collections.emptyList()); + + } + + private Collection<JobGraph> recoverJobs() { + log.info("Recover all persisted job graphs."); + final Collection<JobID> jobIds = getJobIds(); + final Collection<JobGraph> recoveredJobGraphs = new ArrayList<>(); + + for (JobID jobId : jobIds) { + recoveredJobGraphs.add(recoverJob(jobId)); + } + + log.info("Successfully recovered {} persisted job graphs.", recoveredJobGraphs.size()); + + return recoveredJobGraphs; + } + + private Collection<JobID> getJobIds() { + try { + return jobGraphStore.getJobIds(); + } catch (Exception e) { + throw new FlinkRuntimeException( + "Could not retrieve job ids of persisted jobs.", + e); + } + } + + private JobGraph recoverJob(JobID jobId) { + log.info("Trying to recover job with job id {}.", jobId); + try { + return jobGraphStore.recoverJobGraph(jobId); + } catch (Exception e) { + throw new FlinkRuntimeException( + String.format("Could not recover job with job id %s.", jobId), + e); + } + } + + @Override + protected CompletableFuture<Void> onClose() { + // Here we need to first call super.onClose because we want to stop the DispatcherService first Review comment: IIRC one of the original purposes for `onClose` is releasing ourselves from calling `super.close()` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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