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https://issues.apache.org/jira/browse/HDFS-10323?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Aaron T. Myers updated HDFS-10323:
----------------------------------
    Affects Version/s: 2.6.0
     Target Version/s: 3.0.0-beta1

Agree, seems incompatible. Targeting for 3.0.

> transient deleteOnExit failure in ViewFileSystem due to close() ordering
> ------------------------------------------------------------------------
>
>                 Key: HDFS-10323
>                 URL: https://issues.apache.org/jira/browse/HDFS-10323
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: federation
>    Affects Versions: 2.6.0
>            Reporter: Ben Podgursky
>
> After switching to using a ViewFileSystem, fs.deleteOnExit calls began 
> failing frequently, displaying this error on failure:
> 16/04/21 13:56:24 INFO fs.FileSystem: Ignoring failure to deleteOnExit for 
> path /tmp/delete_on_exit_test_123/a438afc0-a3ca-44f1-9eb5-010ca4a62d84
> Since FileSystem eats the error involved, it is difficult to be sure what the 
> error is, but I believe what is happening is that the ViewFileSystem’s child 
> FileSystems are being close()’d before the ViewFileSystem, due to the random 
> order ClientFinalizer closes FileSystems; so then when the ViewFileSystem 
> tries to close(), it tries to forward the delete() calls to the appropriate 
> child, and fails because the child is already closed.
> I’m unsure how to write an actual Hadoop test to reproduce this, since it 
> involves testing behavior on actual JVM shutdown.  However, I can verify that 
> while
> {code:java}
> fs.deleteOnExit(randomTemporaryDir);

> {code}
> regularly (~50% of the time) fails to delete the temporary directory, this 
> code:
> {code:java}
> ViewFileSystem viewfs = (ViewFileSystem)fs1;

> for (FileSystem fileSystem : viewfs.getChildFileSystems()) {
  
>   if (fileSystem.exists(randomTemporaryDir)) {
    
>     fileSystem.deleteOnExit(randomTemporaryDir);
  
>   }
> 
}

> {code}
> always successfully deletes the temporary directory on JVM shutdown.
> I am not very familiar with FileSystem inheritance hierarchies, but at first 
> glance I see two ways to fix this behavior:
> 1)  ViewFileSystem could forward deleteOnExit calls to the appropriate child 
> FileSystem, and not hold onto that path itself.
> 2) FileSystem.Cache.closeAll could first close all ViewFileSystems, then all 
> other FileSystems.  
> Would appreciate any thoughts of whether this seems accurate, and thoughts 
> (or help) on the fix.



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