tanliang created FLINK-34557:
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Summary: When the Flink task ends in application mode, there may
be issues with the Znode and HDFS files not being deleted
Key: FLINK-34557
URL: https://issues.apache.org/jira/browse/FLINK-34557
Project: Flink
Issue Type: Improvement
Components: Deployment / YARN, Runtime / Task
Affects Versions: 1.16.2, 1.17.0
Reporter: tanliang
Attachments: image-2024-03-01-15-38-48-396.png,
image-2024-03-01-15-39-13-953.png, image-2024-03-01-15-39-39-524.png
In Flink 1.16.2, we all use application mode to submit tasks to Yarn. However,
there are several situations during use that result in Znode not being deleted
and some files on HDFS not being deleted. These should be deleted after the
task is stopped, otherwise it may cause some resource occupancy problems. Below
are the several situations I have encountered:
# After the Flink task is submitted to the cluster, if there is a conflict or
missing jar package, the task will be restarted multiple times by Yarn and
ultimately fail to end. At this point, it will be found that the Znode
persists, and there are files with corresponding appids in the '/.flink'
directory and '/flink/recovery' directory in HDFS
# When using the yarn kill command to kill a task, the task ends directly and
the final state is killed, with the final result being the same as the first one
# When the Flink task is disconnected from zk (we will not analyze the
specific reason for the disconnection), if zk is disconnected from the jm
container, the task will hang and be pulled back by yarn. When the last
disconnection occurs, the task will eventually end and the same result as above
will appear
!image-2024-03-01-15-38-48-396.png|width=877,height=171!
!image-2024-03-01-15-39-13-953.png|width=882,height=174!
!image-2024-03-01-15-39-39-524.png|width=1001,height=67!
*Add：*
Through consulting with the community and other colleagues, we found that the
community had previously raised the issue of Znode not being deleted. Later, by
adding the closeAndCleanupAllData # method, it was uniformly deleted at the end
of a highly available cluster. However, in the aforementioned situations, there
are still issues with file and data residue. Among them, when using the yarn
kill command, after successfully submitting a task to the cluster, Flink would
indicate through console logs that there would be HDFS file residue after
successfully submitting tasks to the cluster, however, I don't understand why
the community did not improve this and instead retained the existence of this
situation. At the same time, we believe that Znode residue should not exist,
regardless of the task status, it must be cleaned up after stopping the task
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