Mailing-List: contact issues-help@flink.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@flink.apache.org
From: mxm <git@git.apache.org>
To: issues@flink.incubator.apache.org
Reply-To: issues@flink.incubator.apache.org
References: <git-pr-2313-flink@git.apache.org>
In-Reply-To: <git-pr-2313-flink@git.apache.org>
Subject: [GitHub] flink pull request #2313: [FLINK-4273] Modify JobClient to attach to running...
Content-Type: text/plain
Message-Id: <20160819081033.8121CE02D4@git1-us-west.apache.org>
Date: Fri, 19 Aug 2016 08:10:33 +0000 (UTC)
archived-at: Fri, 19 Aug 2016 08:10:40 -0000

Github user mxm commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2313#discussion_r75442774
  
    --- Diff: flink-runtime/src/main/java/org/apache/flink/runtime/client/JobClient.java ---
    @@ -118,27 +138,162 @@ public static JobExecutionResult submitJobAndWait(
     			sysoutLogUpdates);
     
     		ActorRef jobClientActor = actorSystem.actorOf(jobClientActorProps);
    -		
    +
    +		Future<Object> submissionFuture = Patterns.ask(
    +				jobClientActor,
    +				new JobClientMessages.SubmitJobAndWait(jobGraph),
    +				new Timeout(AkkaUtils.INF_TIMEOUT()));
    +
    +		return new JobListeningContext(
    +				jobGraph.getJobID(),
    +				submissionFuture,
    +				jobClientActor,
    +				classLoader);
    +	}
    +
    +
    +	/**
    +	 * Attaches to a running Job using the JobID.
    +	 * Reconstructs the user class loader by downloading the jars from the JobManager.
    +	 * @throws JobRetrievalException if anything goes wrong while retrieving the job
    +	 */
    +	public static JobListeningContext attachToRunningJob(
    +			JobID jobID,
    +			ActorGateway jobManagerGateWay,
    +			Configuration configuration,
    +			ActorSystem actorSystem,
    +			LeaderRetrievalService leaderRetrievalService,
    +			FiniteDuration timeout,
    +			boolean sysoutLogUpdates) throws JobRetrievalException {
    +
    +		checkNotNull(jobID, "The jobID must not be null.");
    +		checkNotNull(jobManagerGateWay, "The jobManagerGateWay must not be null.");
    +		checkNotNull(configuration, "The configuration must not be null.");
    +		checkNotNull(actorSystem, "The actorSystem must not be null.");
    +		checkNotNull(leaderRetrievalService, "The jobManagerGateway must not be null.");
    +		checkNotNull(timeout, "The timeout must not be null.");
    +
    +		// retrieve classloader first before doing anything
    +		ClassLoader classloader;
    +		try {
    +			classloader = retrieveClassLoader(jobID, jobManagerGateWay, configuration, timeout);
    +			LOG.info("Reconstructed class loader for Job {}" , jobID);
    +		} catch (Exception e) {
    +			LOG.warn("Couldn't retrieve classloader for {}. Using system class loader", jobID, e);
    +			classloader = JobClient.class.getClassLoader();
    +		}
    +
    +		// we create a proxy JobClientActor that deals with all communication with
    +		// the JobManager. It forwards the job submission, checks the success/failure responses, logs
    +		// update messages, watches for disconnect between client and JobManager, ...
    +		Props jobClientActorProps = JobClientActor.createJobClientActorProps(
    +			leaderRetrievalService,
    +			timeout,
    +			sysoutLogUpdates);
    +
    +		ActorRef jobClientActor = actorSystem.actorOf(jobClientActorProps);
    +
    +		Future<Object> attachmentFuture = Patterns.ask(
    +				jobClientActor,
    +				new JobClientMessages.AttachToJobAndWait(jobID),
    +				new Timeout(AkkaUtils.INF_TIMEOUT()));
    +
    +		return new JobListeningContext(
    +				jobID,
    +				attachmentFuture,
    +				jobClientActor,
    +				classloader);
    +	}
    +
    +	/**
    +	 * Reconstructs the class loader by first requesting information about it at the JobManager
    +	 * and then downloading missing jar files.
    +	 * @param jobID id of job
    +	 * @param jobManager gateway to the JobManager
    +	 * @param config the flink configuration
    +	 * @param timeout timeout for querying the jobmanager
    +	 * @return A classloader that should behave like the original classloader
    +	 * @throws JobRetrievalException if anything goes wrong
    +	 */
    +	public static ClassLoader retrieveClassLoader(
    +		JobID jobID,
    +		ActorGateway jobManager,
    +		Configuration config,
    +		FiniteDuration timeout)
    +		throws JobRetrievalException {
    +
    +		final Object jmAnswer;
    +		try {
    +			jmAnswer = Await.result(
    +				jobManager.ask(
    +					new JobManagerMessages.RequestClassloadingProps(jobID), timeout), timeout);
    +		} catch (Exception e) {
    +			throw new JobRetrievalException(jobID, "JobManager didn't respond", e);
    +		}
    +
    +		if (jmAnswer instanceof JobManagerMessages.ClassloadingProps) {
    +			JobManagerMessages.ClassloadingProps props = ((JobManagerMessages.ClassloadingProps) jmAnswer);
    +
    +			Option<String> jmHost = jobManager.actor().path().address().host();
    +			String jmHostname = jmHost.isDefined() ? jmHost.get() : "localhost";
    +			InetSocketAddress serverAddress = new InetSocketAddress(jmHostname, props.blobManagerPort());
    +			final BlobCache blobClient = new BlobCache(serverAddress, config);
    +
    +			final List<BlobKey> requiredJarFiles = props.requiredJarFiles();
    +			final List<URL> requiredClasspaths = props.requiredClasspaths();
    +
    +			final URL[] allURLs = new URL[requiredJarFiles.size() + requiredClasspaths.size()];
    +
    +			int pos = 0;
    +			for (BlobKey blobKey : props.requiredJarFiles()) {
    +				try {
    +					allURLs[pos++] = blobClient.getURL(blobKey);
    +				} catch (Exception e) {
    +					blobClient.shutdown();
    +					throw new JobRetrievalException(jobID, "Failed to download BlobKey " + blobKey);
    +				}
    +			}
    +
    +			for (URL url : requiredClasspaths) {
    +				allURLs[pos++] = url;
    +			}
    +
    +			return new URLClassLoader(allURLs, JobClient.class.getClassLoader());
    +		} else if (jmAnswer instanceof JobManagerMessages.JobNotFound) {
    +			throw new JobRetrievalException(jobID, "Couldn't retrieve class loader. Job " + jobID + " not found");
    +		} else {
    +			throw new JobRetrievalException(jobID, "Unknown response from JobManager: " + jmAnswer);
    +		}
    +	}
    +
    +	/**
    +	 * Given a JobListeningContext, awaits the result of the job execution that this context is bound to
    +	 * @param listeningContext The listening context of the job execution
    +	 * @return The result of the execution
    +	 * @throws JobExecutionException if anything goes wrong while monitoring the job
    +	 */
    +	public static JobExecutionResult awaitJobResult(JobListeningContext listeningContext) throws JobExecutionException {
    +
    +		final JobID jobID = listeningContext.jobID;
    +		final Future<Object> jobSubmissionFuture = listeningContext.jobResultFuture;
    +		final ClassLoader classLoader = listeningContext.classLoader;
    +
     		// first block handles errors while waiting for the result
    -		Object answer;
    +		final Object answer;
     		try {
    -			Future<Object> future = Patterns.ask(jobClientActor,
    -					new JobClientMessages.SubmitJobAndWait(jobGraph),
    -					new Timeout(AkkaUtils.INF_TIMEOUT()));
    -			
    -			answer = Await.result(future, AkkaUtils.INF_TIMEOUT());
    +			answer = Await.result(jobSubmissionFuture, AkkaUtils.INF_TIMEOUT());
    --- End diff --
    
    That's an issue that was present before in `JobClientActor`. Couldn't we ensure with Akka that the actor sends a message before it dies?


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---