[ 
https://issues.apache.org/jira/browse/HADOOP-3415?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Chris Douglas updated HADOOP-3415:
----------------------------------

    Resolution: Invalid
        Status: Resolved  (was: Patch Available)

This change makes more sense integrated into HADOOP-3628, where the "different 
lifecycle" motivation is not hypothetical. I agree with Alejandro; this isn't a 
valid bug.

> JobEndNotifier isnt synchronized, doesnt check state before acting
> ------------------------------------------------------------------
>
>                 Key: HADOOP-3415
>                 URL: https://issues.apache.org/jira/browse/HADOOP-3415
>             Project: Hadoop Core
>          Issue Type: Bug
>          Components: mapred
>    Affects Versions: 0.19.0
>            Reporter: Steve Loughran
>            Priority: Minor
>         Attachments: hadoop-3415.patch
>
>
> JobEndNotifier is pretty hazardous inside.
> 1. the static startNotifier isnt synchronized, and doesnt check for being 
> already running before it creates a new worker thread. It should be 
> sycnhronized and a no-op if there is a live thread.
> 2. stopNotifier() should be a no-op if already stopped. It MUST NOT call 
> thread.interrupt() in such a state, as thread may be null. 
> 3. the registerNotification method also assumes that the static queue is non 
> null.
> Things would be a lot safer by making this class part of a JobTracker, not a 
> singleton with static methods, as then you could more safely make assumptions 
> about object state. This would not only eliminate a lot of reentrancy 
> problems, but tie the life of the notifier to that of its owner, the 
> JobTracker.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to