[jira] [Created] (MAPREDUCE-6588) default values for PATH for tasks are not quite correct

["Sangjin Lee (JIRA)" <ji...@apache.org>]

Sangjin Lee created MAPREDUCE-6588:
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             Summary: default values for PATH for tasks are not quite correct
                 Key: MAPREDUCE-6588
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-6588
             Project: Hadoop Map/Reduce
          Issue Type: Bug
          Components: mr-am
    Affects Versions: 2.6.0
            Reporter: Sangjin Lee


There are several issues with the way PATH are handled for MR tasks and AMs on Windows.

- it does not get the PWD as part of the path, unlike the non-Windows case (see MAPREDUCE-6021)
- the MR AM doesn't get the Hadoop's bin directory in the path explicitly through mapred configuration; rather, it implicitly inherits it from the node manager (see MAPREDUCE-6577)
- the default value for the MR task PATH uses "%...%" macros which may be expanded on the client side prematurely; this is probably OK for tasks (as it's done by the AM), but not OK for AMs; the late-binding cross-platform macros should be used

I took a stab at addressing these as part of MAPREDUCE-6577, but I realized that it would be a bigger issue than the fix for MAPREDUCE-6577 itself. Thus, I'm filing a separate JIRA to address the Windows side of things.

On a related note, there are quite a few brittle tests on testing these (TestMiniMRChildTask, TestMiniMRClientCluster, etc.) which are built in such a way that the tests pass against the current behavior but don't provide a lot of robust test value. We should also update those tests to make them more robust.



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