accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Keith Turner (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (ACCUMULO-587) Add finalize to TabletServerBatchReader to catch when user forgets to close
Date Wed, 16 May 2012 19:25:07 GMT

    [ https://issues.apache.org/jira/browse/ACCUMULO-587?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13277036#comment-13277036
] 

Keith Turner commented on ACCUMULO-587:
---------------------------------------

It would be interesting to verify this with a test.  Derefernce the batch scanner and call
System.gc() a few times and see if the log message is emitted.  It would be nice to have the
finalize message with a logs message if it works.

As for people relying on it, the finalize() method will be in impl not part of the public
API.  So you have to go digging around to find it.  Could add some javadoc warning against
relying on it.
                
> Add finalize to TabletServerBatchReader to catch when user forgets to close
> ---------------------------------------------------------------------------
>
>                 Key: ACCUMULO-587
>                 URL: https://issues.apache.org/jira/browse/ACCUMULO-587
>             Project: Accumulo
>          Issue Type: Improvement
>          Components: client
>            Reporter: Dennis Patrone
>            Assignee: Billie Rinaldi
>            Priority: Trivial
>
> If a client forgets to close a BatchScanner or BatchDeleter, threads are leaked in the
TabletServerBatchReader implementation.  It would be nice if a finalize method were added
to check and warn the user of such a problem. The thread pool appeared to only be shared with
the TabletServerBatchReaderIterator, which maintains a reference to the TabletServerBatchReader
itself.  So AFAICT if the TabletServerBatchReader is eligible for garbage collection, there
can be no client references to that scanner or any iterators it created (i.e., it _should_
have been closed).
> For example:
> {code}
> protected void finalize() {
>    if (!queryThreadPool.isShutdown()) {
>       // add a logger reference in class initialization
>       log.warn("TabletServerBatchReader not shutdown; did you forget to call close()?");
>       close();
>    }
> }
> {code}
> The same might be true for the TabletServerBatchWriter (it has a close), but I didn't
look into that class.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message