[
https://issues.apache.org/jira/browse/CASSANDRA-3427?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13149312#comment-13149312
]
Mck SembWever commented on CASSANDRA-3427:
------------------------------------------
bq. Does heap usage stay high-post startup? Can you try forcing a full GC to
check that?
Yes. GC doesn't seem to help, i'll attach a munin graph that shows it over
time. It was running for a number of days just under 20G, but you can see from
that how "squeezed" it was.
> CompressionMetadata is not shared across threads, we create a new one for
> each read
> -----------------------------------------------------------------------------------
>
> Key: CASSANDRA-3427
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3427
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.0.0
> Reporter: Sylvain Lebresne
> Assignee: Sylvain Lebresne
> Labels: compression
> Fix For: 1.0.2
>
> Attachments: 3427.patch, 3427_v2.patch, CASSANDRA-3427.patch
>
>
> The CompressionMetada holds the compressed block offsets in memory. Without
> being absolutely huge, this is still of non-negligible size as soon as you
> have a bit of data in the DB. Reallocating this for each read is a very bad
> idea.
> Note that this only affect range queries, since "normal" queries uses
> CompressedSegmentedFile that does reuse a unique CompressionMetadata instance.
--
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
