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https://issues.apache.org/jira/browse/HBASE-16650?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Anoop Sam John updated HBASE-16650:
-----------------------------------
    Status: Patch Available  (was: Open)

> Wrong usage of BlockCache eviction stat for heap memory tuning
> --------------------------------------------------------------
>
>                 Key: HBASE-16650
>                 URL: https://issues.apache.org/jira/browse/HBASE-16650
>             Project: HBase
>          Issue Type: Sub-task
>            Reporter: Anoop Sam John
>            Assignee: Anoop Sam John
>             Fix For: 2.0.0
>
>         Attachments: HBASE-16650.patch
>
>
> 1. We use the stat evictedBlocksCount - A block can get evicted because of 
> eviction thread due to lack of space or because of removal of an HFile itself 
> (After a compaction). We should not consider the latter in the tune decision 
> at all. These are actually invalidation of blocks. Should the stat counter 
> itself not use this count of evicted blocks? I think yes. This will give 
> wrong message to users that there are lot of real eviction happening.
> 2. In case L1+ L2 combined block cache, what we use is the sum of evictions 
> from both. But we will be tuning L1 size alone. Eviction count from L2 should 
> not affect the tuning of L1



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