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https://issues.apache.org/jira/browse/HDFS-14500?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16846127#comment-16846127
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Erik Krogen commented on HDFS-14500:
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Yes, your understanding is correct. Considering that the changes are in
{{StartupProgress}} and every phase in {{StartupProgress}} is treated
identically, I don't think it matters which phase we use in the test. I used
{{LOADING_FSIMAGE}} since that is the phase which the test was already
modifying. Let me know if you still think we should change it.
Uploading v001 patch to fix whitespace and test failure.
> NameNode StartupProgress continues to report edit log segments after the
> LOADING_EDITS phase is finished
> --------------------------------------------------------------------------------------------------------
>
> Key: HDFS-14500
> URL: https://issues.apache.org/jira/browse/HDFS-14500
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 3.2.0, 2.9.2, 3.0.3, 2.8.5, 3.1.2
> Reporter: Erik Krogen
> Assignee: Erik Krogen
> Priority: Major
> Attachments: HDFS-14500.000.patch
>
>
> When testing out a cluster with the edit log tailing fast path feature
> enabled (HDFS-13150), an unrelated issue caused the NameNode to remain in
> safe mode for an extended period of time, preventing the NameNode from fully
> completing its startup sequence. We noticed that the Startup Progress web UI
> displayed many edit log segments (millions of them).
> I traced this problem back to {{StartupProgress}}. Within
> {{FSEditLogLoader}}, the loader continually tries to update the startup
> progress with a new {{Step}} any time that it loads edits. Per the Javadoc
> for {{StartupProgress}}, this should be a no-op once startup is completed:
> {code:title=StartupProgress.java}
> * After startup completes, the tracked data is frozen. Any subsequent
> updates
> * or counter increments are no-ops.
> {code}
> However, {{StartupProgress}} only implements that logic once the _entire_
> startup sequence has been completed. When {{FSEditLogLoader}} calls
> {{addStep()}}, it adds it into the {{LOADING_EDITS}} phase:
> {code:title=FSEditLogLoader.java}
> StartupProgress prog = NameNode.getStartupProgress();
> Step step = createStartupProgressStep(edits);
> prog.beginStep(Phase.LOADING_EDITS, step);
> {code}
> This phase, in our case, ended long before, so it is nonsensical to continue
> to add steps to it. I believe it is a bug that {{StartupProgress}} accepts
> such steps instead of ignoring them; once a phase is complete, it should no
> longer change.
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