Mailing-List: contact hbase-dev-help@hadoop.apache.org; run by ezmlm
Precedence: bulk
Reply-To: hbase-dev@hadoop.apache.org
Message-ID: <1108114702.1256231939795.JavaMail.jira@brutus>
Date: Thu, 22 Oct 2009 17:18:59 +0000 (UTC)
From: "stack (JIRA)" <jira@apache.org>
To: hbase-dev@hadoop.apache.org
Subject: [jira] Commented: (HBASE-1927) Scanners not closed properly in
 certain circumstances (memory leak)
In-Reply-To: <1309577882.1256196779387.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/HBASE-1927?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12768765#action_12768765 ] 

stack commented on HBASE-1927:
------------------------------

+1 for branch and trunk.  Thanks Erik for the fix.

> Scanners not closed properly in certain circumstances (memory leak)
> -------------------------------------------------------------------
>
>                 Key: HBASE-1927
>                 URL: https://issues.apache.org/jira/browse/HBASE-1927
>             Project: Hadoop HBase
>          Issue Type: Bug
>          Components: regionserver
>    Affects Versions: 0.20.1
>            Reporter: Erik Rozendaal
>            Assignee: Jonathan Gray
>             Fix For: 0.20.2, 0.21.0
>
>         Attachments: HBASE-1927-v1.patch
>
>
> Scanners are sometimes leaked by the KeyValueHeap class. The constructor adds each scanner to a heap, but only if the scanner's peek() method returns not null (line 58). Otherwise the scanner is dropped without being closed.
> Unfortunately some scanners (like StoreScanner and MemStoreScanner) register themselves to some global list when constructed and only deregister on close(). This can cause a memory leak, for example with MemStoreScanners on an empty memory store.
> The quick fix is to add an else clause to the if on line 58:
> } else {
>   scanner.close()
> }
> The root cause is that ownership of the scanners is transferred from the caller to the KeyValueHeap on construction. Maybe this should be made clear in the documentation or changed.

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