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https://issues.apache.org/jira/browse/FLINK-4485?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15493019#comment-15493019
]
ASF GitHub Bot commented on FLINK-4485:
---------------------------------------
GitHub user mxm opened a pull request:
https://github.com/apache/flink/pull/2499
[FLINK-4485] close and remove user class loader after job completion
Keeping the user class loader around after job completion may lead to
excessive temp space usage because all user jars are kept until the
class loader is garbage collected. Tests showed that garbage collection
can be delayed for a long time after the class loader is not referenced
anymore. Note that for the class loader to not be referenced anymore,
its job has to be removed from the archive.
The fastest way to minimize temp space usage is to close and remove the
URLClassloader after job completion. This requires us to keep a
serializable copy of all data which needs the user class loader after
job completion, e.g. to display data on the web interface.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/mxm/flink FLINK-4485
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/flink/pull/2499.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #2499
----
commit 6ed17b9f5b9c13c80200ccf3db82bbfe727830bb
Author: Maximilian Michels <m...@apache.org>
Date: 2016-09-15T09:00:58Z
[FLINK-4485] close and remove user class loader after job completion
Keeping the user class loader around after job completion may lead to
excessive temp space usage because all user jars are kept until the
class loader is garbage collected. Tests showed that garbage collection
can be delayed for a long time after the class loader is not referenced
anymore. Note that for the class loader to not be referenced anymore,
its job has to be removed from the archive.
The fastest way to minimize temp space usage is to close and remove the
URLClassloader after job completion. This requires us to keep a
serializable copy of all data which needs the user class loader after
job completion, e.g. to display data on the web interface.
----
> Finished jobs in yarn session fill /tmp filesystem
> --------------------------------------------------
>
> Key: FLINK-4485
> URL: https://issues.apache.org/jira/browse/FLINK-4485
> Project: Flink
> Issue Type: Bug
> Components: JobManager
> Affects Versions: 1.1.0
> Reporter: Niels Basjes
> Assignee: Maximilian Michels
> Priority: Blocker
>
> On a Yarn cluster I start a yarn-session with a few containers and task slots.
> Then I fire a 'large' number of Flink batch jobs in sequence against this
> yarn session. It is the exact same job (java code) yet it gets different
> parameters.
> In this scenario it is exporting HBase tables to files in HDFS and the
> parameters are about which data from which tables and the name of the target
> directory.
> After running several dozen jobs the jobs submission started to fail and we
> investigated.
> We found that the cause was that on the Yarn node which was hosting the
> jobmanager the /tmp file system was full (4GB was 100% full).
> How ever the output of {{du -hcs /tmp}} showed only 200MB in use.
> We found that a very large file (we guess it is the jar of the job) was put
> in /tmp , used, deleted yet the file handle was not closed by the jobmanager.
> As soon as we killed the jobmanager the disk space was freed.
> The summary of the impact of this is that a yarn-session that receives enough
> jobs brings down the Yarn node for all users.
> See parts of the output we got from {{lsof}} below.
> {code}
> COMMAND PID USER FD TYPE DEVICE SIZE
> NODE NAME
> java 15034 nbasjes 550r REG 253,17 66219695
> 245
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000003
> (deleted)
> java 15034 nbasjes 551r REG 253,17 66219695
> 252
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000007
> (deleted)
> java 15034 nbasjes 552r REG 253,17 66219695
> 267
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000012
> (deleted)
> java 15034 nbasjes 553r REG 253,17 66219695
> 250
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000005
> (deleted)
> java 15034 nbasjes 554r REG 253,17 66219695
> 288
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000018
> (deleted)
> java 15034 nbasjes 555r REG 253,17 66219695
> 298
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000025
> (deleted)
> java 15034 nbasjes 557r REG 253,17 66219695
> 254
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000008
> (deleted)
> java 15034 nbasjes 558r REG 253,17 66219695
> 292
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000019
> (deleted)
> java 15034 nbasjes 559r REG 253,17 66219695
> 275
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000013
> (deleted)
> java 15034 nbasjes 560r REG 253,17 66219695
> 159
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000002
> (deleted)
> java 15034 nbasjes 562r REG 253,17 66219695
> 238
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000001
> (deleted)
> java 15034 nbasjes 568r REG 253,17 66219695
> 246
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000004
> (deleted)
> java 15034 nbasjes 569r REG 253,17 66219695
> 255
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000009
> (deleted)
> java 15034 nbasjes 571r REG 253,17 66219695
> 299
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000026
> (deleted)
> java 15034 nbasjes 572r REG 253,17 66219695
> 293
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000020
> (deleted)
> java 15034 nbasjes 574r REG 253,17 66219695
> 256
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000010
> (deleted)
> java 15034 nbasjes 575r REG 253,17 66219695
> 302
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000029
> (deleted)
> java 15034 nbasjes 576r REG 253,17 66219695
> 294
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000021
> (deleted)
> java 15034 nbasjes 577r REG 253,17 66219695
> 262
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000011
> (deleted)
> java 15034 nbasjes 578r REG 253,17 66219695
> 251
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000006
> (deleted)
> java 15034 nbasjes 580r REG 253,17 66219695
> 295
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000022
> (deleted)
> java 15034 nbasjes 581r REG 253,17 66219695
> 300
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000027
> (deleted)
> java 15034 nbasjes 582r REG 253,17 66219695
> 188
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/cache/blob_e318d1698aa6e7dc91e5f4a9f8ba29781aebd8c4
> (deleted)
> java 15034 nbasjes 585r REG 253,17 66219695
> 279
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000014
> (deleted)
> java 15034 nbasjes 586r REG 253,17 66219695
> 296
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000023
> (deleted)
> java 15034 nbasjes 588r REG 253,17 66219695
> 301
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000028
> (deleted)
> java 15034 nbasjes 589r REG 253,17 66219695
> 297
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000024
> (deleted)
> java 15034 nbasjes 598r REG 253,17 66219695
> 280
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000015
> (deleted)
> java 15034 nbasjes 601r REG 253,17 66219695
> 289
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000016
> (deleted)
> java 15034 nbasjes 604r REG 253,17 66219695
> 284
> /tmp/blobStore-fbe9c4cf-1f85-48cb-aad9-180e8d4ec7ce/incoming/temp-00000017
> (deleted)
> {code}
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