[
https://issues.apache.org/jira/browse/CASSANDRA-5661?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13701495#comment-13701495
]
Ben Manes commented on CASSANDRA-5661:
--------------------------------------
"rarely explicitly invalidated" is regards to a cache, as Jonathan originally
described the problem as a multimap cache instead of as an object pool. He also
expressed concern with evicting a block of buffers at once when he conceived of
the same model that you implemented.
I am intimately familiar with Guava's cache as I designed the algorithms,
ported and wrote code for it, and advised on the api. Unfortunately I am not
familiar with Cassandra's needs and its code, so the pool was implemented based
on a brief description of the problem and ideal behavior.
It was a fun exercise for a long weekend. I'd recommend writing tests and
benchmarks, which unfortunately appears to be missing with the patch in its
current form. Of couse use whatever makes the most sense.
> Discard pooled readers for cold data
> ------------------------------------
>
> Key: CASSANDRA-5661
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5661
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.2.1
> Reporter: Jonathan Ellis
> Assignee: Pavel Yaskevich
> Fix For: 1.2.7
>
> Attachments: CASSANDRA-5661.patch, DominatorTree.png, Histogram.png
>
>
> Reader pooling was introduced in CASSANDRA-4942 but pooled
> RandomAccessReaders are never cleaned up until the SSTableReader is closed.
> So memory use is "the worst case simultaneous RAR we had open for this file,
> forever."
> We should introduce a global limit on how much memory to use for RAR, and
> evict old ones.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
