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https://issues.apache.org/jira/browse/CASSANDRA-3427?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13149637#comment-13149637
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Jonathan Ellis commented on CASSANDRA-3427:
-------------------------------------------

What version exactly are you running now?  1.0.3?  1.0.2 + 3427?  Something 
else?
                
> 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, 
> jmx_jvm_memory-month.png, jmx_jvm_memory-week.png
>
>
> 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.
> ( Background: http://thread.gmane.org/gmane.comp.db.cassandra.user/21362 )

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