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https://issues.apache.org/jira/browse/HDFS-3876?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Eli Collins updated HDFS-3876:
------------------------------

    Attachment: hdfs-3876.txt

TestViewFsTrash failed because the test deletes "/" and we now get server 
defaults on the path (to get the trash configuration), which fails for viewfs 
for "/" because "/" is not associated with a file system and we fail due to a 
NotInMoutPointException.

Updated patch, catch Exception rather than IOE when obtaining server defaults 
so we fail the delete when we fail to get server defaults (rather than 
potentially ignoring the server trash configuration for transient errors 
getting server defaults) and updated TestTrash to not fail the test when we 
fail due to obtaining server defaults (which is what should happen in the 
viewfs case).
                
> NN should not RPC to self to find trash defaults (causes deadlock)
> ------------------------------------------------------------------
>
>                 Key: HDFS-3876
>                 URL: https://issues.apache.org/jira/browse/HDFS-3876
>             Project: Hadoop HDFS
>          Issue Type: Bug
>          Components: name-node
>    Affects Versions: 2.2.0-alpha
>            Reporter: Todd Lipcon
>            Assignee: Eli Collins
>            Priority: Blocker
>         Attachments: hdfs-3876.txt, hdfs-3876.txt, hdfs-3876.txt
>
>
> When transitioning a SBN to active, I ran into the following situation:
> - the TrashPolicy first gets loaded by an IPC Server Handler thread. The 
> {{initialize}} function then tries to make an RPC to the same node to find 
> out the defaults.
> - This is happening inside the NN write lock (since it's part of the active 
> initialization). Hence, all of the other handler threads are already blocked 
> waiting to get the NN lock.
> - Since no handler threads are free, the RPC blocks forever and the NN never 
> enters active state.
> We need to have a general policy that the NN should never make RPCs to itself 
> for any reason, due to potential for deadlocks like this.

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