[
https://issues.apache.org/jira/browse/HADOOP-3546?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12604807#action_12604807
]
Amareshwari Sriramadasu commented on HADOOP-3546:
-------------------------------------------------
The problem is added by the code for Joining cleanup thread through HADOOP-2393.
TaskTracker is waiting for the task cleanup thread to come out. But taskcleanup
thread comes out only when the flag _shuttingDown_ is set true. So, the
tasktracker is stuck in close().
After analysing the code in TaskTracker.java, these following improvements in
the code will actually fix the bug,
1. _taskCleanupThread_ is started by static code block. That should be moved to
_initialize()_. Since we want to stop the thread and start again in the
reintialization.
2. There are two flags _running_ and _shuttingDown_. _running_ is set true in
_intialize()_ once all the data structures are intialized , all the threads and
servers are started etc.. And _shuttingDown_ is set in the method _shutdown()_
. _shutdown()_ is nothing but _close()_ and stops the StatusHttpServer. So,
we can move _shuttingDown_ to _close()_ and rename it to _closing_.
3.The following code in TaskTracker.run() is not necessary:
{noformat} if (shuttingDown) { return; } {noformat}
Since the flag is never set in the loop.
4. _intialize()_ is called even for Denied tasktracker before shutting down
(easily reproducible). So, We can call _intialize()_ only if task tracker is
stale state.
5. The method _isRunning()_ (introduced in HADOOP-2393) can be removed and the
flag can be directly accessed from the thread.
> TaskTracker re-initialization gets stuck in cleaning up
> -------------------------------------------------------
>
> Key: HADOOP-3546
> URL: https://issues.apache.org/jira/browse/HADOOP-3546
> Project: Hadoop Core
> Issue Type: Bug
> Components: mapred
> Affects Versions: 0.18.0
> Reporter: Amareshwari Sriramadasu
> Assignee: Amareshwari Sriramadasu
> Priority: Blocker
> Fix For: 0.18.0
>
>
> If TaskTracker gets reinit action, it is stuck in joining task cleanup
> thread.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
