accumulo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From David Medinets <>
Subject Re: [jira] [Commented] (ACCUMULO-624) iterators may open lots of compressors
Date Thu, 21 Jun 2012 17:38:39 GMT
Is the testing code simple enough to attach to this ticket? I ask
because others might want to replicate your results.

On Thu, Jun 21, 2012 at 12:27 PM, Keith Turner (JIRA) <> wrote:
>    [
> Keith Turner commented on ACCUMULO-624:
> ---------------------------------------
> A work around for this issue is to enable the block cache for the table.  This will
cause rfile blocks to be read into memory and closed immediately, releasing the decompressor.
 A decompressor will not be kept for each deep copy in this case.
> I did some test with the intersecting iterator to verify this.  W/o cache querying 5
terms would allocate 5 decompressors.  W/ cache only one decompressor was allocated.
>> iterators may open lots of compressors
>> --------------------------------------
>>                 Key: ACCUMULO-624
>>                 URL:
>>             Project: Accumulo
>>          Issue Type: Bug
>>          Components: tserver
>>            Reporter: Eric Newton
>>            Assignee: Keith Turner
>> A large iterator tree may create many instances of Compressors.  These instances
are pulled from a pool that never decreases in size.  So, if 50 simultaneous queries are
run over dozens of files, each with a complex iterator stack, there will be thousands of compressors
created.  Each of these holds a large buffer.  This can cause the server to run out of memory.
> --
> This message is automatically generated by JIRA.
> If you think it was sent incorrectly, please contact your JIRA administrators:!default.jspa
> For more information on JIRA, see:

View raw message