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https://issues.apache.org/jira/browse/MAPREDUCE-6032?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14097638#comment-14097638
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Benjamin Zhitomirsky commented on MAPREDUCE-6032:
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[Daryn
Sharp|https://issues.apache.org/jira/secure/ViewProfile.jspa?name=daryn], first
time I misunderstood your question. AFAIU now you suppose that *given* all my
fixes in JobHistoryUtils we shouldn't bother to qualify the path in
JobHistoryEventHandler, right?
You are right! However while it looks like we don't really have to qualify the
paths right now, doing so is much safer for any future changes. If paths are
qualified they will never be misused. Since there is only one-time overhead in
this operation we won't suffer from mentionable performance penalties if we
leave it as-is.
> Unable to check mapreduce job status if submitted using a non-default namenode
> ------------------------------------------------------------------------------
>
> Key: MAPREDUCE-6032
> URL: https://issues.apache.org/jira/browse/MAPREDUCE-6032
> Project: Hadoop Map/Reduce
> Issue Type: Bug
> Components: jobhistoryserver
> Affects Versions: 2.0.5-alpha, 2.1.1-beta, 2.0.6-alpha, 2.2.0, 2.3.0,
> 2.2.1, 2.4.1
> Environment: Any
> Reporter: Benjamin Zhitomirsky
> Assignee: Benjamin Zhitomirsky
> Fix For: trunk
>
> Attachments: MAPREDUCE-6032.1.patch, MAPREDUCE-6032.patch
>
> Original Estimate: 24h
> Time Spent: 24h
> Remaining Estimate: 0h
>
> When MRv2 job container runs in a context of non-default file system
> JobHistoryUtils.java obtains mapreduce.jobhistory.done-dir and
> mapreduce.jobhistory.intermediate-done-dir as a non-qualified paths (e.g.
> /mapred/history). This path is considered to belong to the current
> container's context. As result the application history is being written to
> another file system and job history server is unable to pick it up, because
> it expects it to be found on the default file system. Currently providing
> fully qualified path to those parameters is not supported as well, because of
> a bug in JobHistoryEventHandler.
> After this fix two scenarios will be supported:
> - mapreduce.jobhistory.done-dir and
> mapreduce.jobhistory.intermediate-done-dir (and the staging directory BTW)
> will support a fully qualified path
> - If a non-qualified path is configured then it will always be defaulted to
> the default file system (core-site.xml). That's how consistency of history
> location will be archived
> Implementation notes:
> - FileSystem#makeQualified throws exception if specified path belongs to
> another file system. However FileContext#makeQualified work properly in this
> case, and this is the meaning of the fix in JobHistoryEventHandler. I was not
> ready to change behavior FileSystem#makeQualified because much more thought
> is required. I afraid that many users expect such behavior, and fixing it
> would break their code.
> - The fix in JobHistoryUtils detects non-default namenode configuration only
> if it comes from some "real" configuration: core-default.xml is ignored. This
> is done primary as a kind of test hook, because otherwise setting
> fs.defaultFS value during test executions would be always recognized by
> JobHistoryUtils as a non-default namenode against 'file:///' specified in
> core-default.xml.
> (Remark. Note that makeQualified doesn't behave properly with file:///
> filesystem, for example:
> new Path("file:///dir/subdir").makeQualified(new URI("hdfs://server:8020"),
> new Path("/dir"))
> Returns: "file://server:8020/dir/subdir" which doesn't make sense.
> However I don't believe it worth fixing, since nobody really case about local
> file system besides tests. My fix just ensures that all tests run smoothly by
> ignoring core-default.xml file system in the logic.)
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