Wang Jichao created FLINK-21274:
-----------------------------------
Summary: At per-job mode，when the upload speed of the HDFS file
system is slow, the task exits abnormally, and the task archive file upload
fails.
Key: FLINK-21274
URL: https://issues.apache.org/jira/browse/FLINK-21274
Project: Flink
Issue Type: Bug
Components: Runtime / Coordination
Affects Versions: 1.12.0, 1.11.0, 1.10.1
Reporter: Wang Jichao
Attachments: 1.png, 2.png,
application_1612404624605_0010-JobManager.log
This is a partial configuration of my Flink History service(flink-conf.yaml).
{code:java}
jobmanager.archive.fs.dir: hdfs://hdfsHACluster/flink/completed-jobs/
historyserver.archive.fs.dir: hdfs://hdfsHACluster/flink/completed-jobs/
{code}
I used {color:#0747a6}flink run -m yarn-cluster
/cloud/service/flink/examples/batch/WordCount.jar{color} to submit a WorkCount
task to the Yarn cluster. Under normal circumstances, after the task is
completed, the task execution information will be archived to HDFS, and then
the JobManager process will exit. However, when this archiving process takes a
long time (maybe the HDFS write speed is slow), the task archive file upload
fails.
The specific reproduction method is as follows:
Modify the
{color:#0747a6}org.apache.flink.runtime.history.FsJobArchivist#archiveJob{color}
method to add a 5-second wait before the HDFS write action (simulating a slow
write speed scenario).
{code:java}
public static Path archiveJob(Path rootPath, JobID jobId,
Collection<ArchivedJson> jsonToArchive)
throws IOException {
try {
FileSystem fs = rootPath.getFileSystem();
Path path = new Path(rootPath, jobId.toString());
OutputStream out = fs.create(path, FileSystem.WriteMode.NO_OVERWRITE);
try {
LOG.info("===========================Wait 5 seconds..");
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
try (JsonGenerator gen = jacksonFactory.createGenerator(out,
JsonEncoding.UTF8)) {
... // Part of the code is omitted here
} catch (Exception e) {
fs.delete(path, false);
throw e;
}
LOG.info("Job {} has been archived at {}.", jobId, path);
return path;
} catch (IOException e) {
LOG.error("Failed to archive job.", e);
throw e;
}
}
{code}
After I make the above changes to the code, I cannot find the corresponding
task on Flink's HistoryServer(Refer to Figure 1.png and Figure 2.png).
Then I went to Yarn to browse the JobManager log (see attachment
application_1612404624605_0010-JobManager.log for log details), and found that
the following logs are missing in the task log:
{code:java}
INFO entrypoint.ClusterEntrypoint: Terminating cluster entrypoint process
YarnJobClusterEntrypoint with exit code 0.{code}
Usually, if the task exits normally, a similar log will be printed before
executing {color:#0747a6}System.exit(returnCode){color}.
If no Exception information is found in the JobManager log, the above situation
occurs, indicating that the JobManager is running to a certain point, and there
is no user thread in the JobManager process, which causes the program to exit
without completing the normal process.
Eventually I found out that multiple services (for example: ioExecutor,
metricRegistry, commonRpcService) were exited asynchronously in
{color:#0747a6}org.apache.flink.runtime.entrypoint.ClusterEntrypoint#stopClusterServices{color},
and multiple services would be exited in the shutdown() method of
metricRegistry (for example : executor), these exit actions are executed
asynchronously and in parallel. If ioExecutor or executor exits last, it will
cause the above problems.
I hope to modify the following code to solve this problem. If it is determined
that this is a problem (this problem will affect all versions above 1.9),
please assign the ticket to me, thank you.
Only need to modify the
{color:#0747a6}org.apache.flink.runtime.entrypoint.ClusterEntrypoint#runClusterEntrypoint{color}
method:
{code:java}
public static void runClusterEntrypoint(ClusterEntrypoint clusterEntrypoint) {
final String clusterEntrypointName =
clusterEntrypoint.getClass().getSimpleName();
try {
clusterEntrypoint.startCluster();
} catch (ClusterEntrypointException e) {
LOG.error(String.format("Could not start cluster entrypoint %s.",
clusterEntrypointName), e);
System.exit(STARTUP_FAILURE_RETURN_CODE);
}
int returnCode;
Throwable throwable = null;
try {
returnCode = clusterEntrypoint.getTerminationFuture().get().processExitCode();
} catch (Throwable e) {
throwable = e;
returnCode = RUNTIME_FAILURE_RETURN_CODE;
}
LOG.info("Terminating cluster entrypoint process {} with exit code {}.",
clusterEntrypointName, returnCode, throwable);
System.exit(returnCode);
}{code}
The purpose of the modification is to ensure that the Main thread exits last.
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