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https://issues.apache.org/jira/browse/STORM-837?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14642261#comment-14642261
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ASF GitHub Bot commented on STORM-837:
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Github user arunmahadevan commented on the pull request:
https://github.com/apache/storm/pull/644#issuecomment-125086304
@harshach Are you saying that we don't support time based rotation at all?
The current approach automatically turns off exactly once if TimedRotation is
in use, so that who want to use time based rotation would still be able to use
it with the limitation that they will not get exactly once semantics.
I also think we can do the same with max file size in case of size based
rotation policy.
> HdfsState ignores commits
> -------------------------
>
> Key: STORM-837
> URL: https://issues.apache.org/jira/browse/STORM-837
> Project: Apache Storm
> Issue Type: Bug
> Reporter: Robert Joseph Evans
> Assignee: Arun Mahadevan
> Priority: Critical
>
> HdfsState works with trident which is supposed to provide exactly once
> processing. It does this two ways, first by informing the state about
> commits so it can be sure the data is written out, and second by having a
> commit id, so that double commits can be handled.
> HdfsState ignores the beginCommit and commit calls, and with that ignores the
> ids. This means that if you use HdfsState and your worker crashes you may
> both lose data and get some data twice.
> At a minimum the flush and file rotation should be tied to the commit in some
> way. The commit ID should at a minimum be written out with the data so
> someone reading the data can have a hope of deduping it themselves.
> Also with the rotationActions it is possible for a file that was partially
> written is leaked, and never moved to the final location, because it is not
> rotated. I personally think the actions are too generic for this case and
> need to be deprecated.
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