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https://issues.apache.org/jira/browse/CASSANDRA-1878?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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T Jake Luciani updated CASSANDRA-1878:
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Attachment: 1878_v2.txt
Tested before and after compaction with and without patch, and saw the KeyCache
hit rate remain high with this patch post compaction. Also, the Key Cache hit
rate is no longer NaN after compaction.
I removed a mistaken include in v2.
+1
> Minimize Key Cache Invalidation by Compaction
> ---------------------------------------------
>
> Key: CASSANDRA-1878
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1878
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Tyler Hobbs
> Assignee: Jonathan Ellis
> Fix For: 0.6.9, 0.7.0
>
> Attachments: 1878.txt, 1878_v2.txt
>
>
> Currently, compactions invalidate key cache entries that pointed to the
> SSTables that were compacted. This results in a sudden increase in the
> number of seeks necessary for reads immediately after compaction. When
> writing out a new SSTable after a compaction, it seems like it should be
> possible to store a list of keys that are currently cached but would be
> invalidated along with their new position in the new SSTable. Matt Dennis
> also seems to think this would be relatively easy to do.
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