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https://issues.apache.org/jira/browse/HBASE-8370?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13694389#comment-13694389
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Varun Sharma commented on HBASE-8370:
-------------------------------------

We can make the hit percent a double.

But if we never evict index blocks, one option is to only count DataBlocks for 
HitPercent, CacheHitCount, CacheMissCount. I know that is not the case for 
0.94. Is that the case for trunk or can we change these metrics to only 
instrument data blocks then ?

Anyone else have opinions ?
                
> Report data block cache hit rates apart from aggregate cache hit rates
> ----------------------------------------------------------------------
>
>                 Key: HBASE-8370
>                 URL: https://issues.apache.org/jira/browse/HBASE-8370
>             Project: HBase
>          Issue Type: Improvement
>          Components: metrics
>            Reporter: Varun Sharma
>            Assignee: Varun Sharma
>            Priority: Minor
>
> Attaching from mail to [email protected]
> I am wondering whether the HBase cachingHitRatio metrics that the region 
> server UI shows, can get me a break down by data blocks. I always see this 
> number to be very high and that could be exagerated by the fact that each 
> lookup hits the index blocks and bloom filter blocks in the block cache 
> before retrieving the data block. This could be artificially bloating up the 
> cache hit ratio.
> Assuming the above is correct, do we already have a cache hit ratio for data 
> blocks alone which is more obscure ? If not, my sense is that it would be 
> pretty valuable to add one.

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