[ 
https://issues.apache.org/jira/browse/HADOOP-8770?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13449064#comment-13449064
 ] 

Hudson commented on HADOOP-8770:
--------------------------------

Integrated in Hadoop-Common-trunk-Commit #2687 (See 
[https://builds.apache.org/job/Hadoop-Common-trunk-Commit/2687/])
    HADOOP-8770. NN should not RPC to self to find trash defaults. Contributed 
by Eli Collins (Revision 1381319)

     Result = SUCCESS
eli : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1381319
Files : 
* /hadoop/common/trunk/hadoop-common-project/hadoop-common/CHANGES.txt
* 
/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/Trash.java
* 
/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/TrashPolicyDefault.java
* 
/hadoop/common/trunk/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/TestTrash.java
* 
/hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSShell.java
* 
/hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestHDFSTrash.java

                
> NN should not RPC to self to find trash defaults (causes deadlock)
> ------------------------------------------------------------------
>
>                 Key: HADOOP-8770
>                 URL: https://issues.apache.org/jira/browse/HADOOP-8770
>             Project: Hadoop Common
>          Issue Type: Bug
>          Components: trash
>    Affects Versions: 2.2.0-alpha
>            Reporter: Todd Lipcon
>            Assignee: Eli Collins
>            Priority: Blocker
>             Fix For: 2.2.0-alpha
>
>         Attachments: hdfs-3876.txt, 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.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Reply via email to