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https://issues.apache.org/jira/browse/HBASE-4089?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13073635#comment-13073635
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Jean-Daniel Cryans commented on HBASE-4089:
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Nice document Doug, it puts everyone else to shame :)
I don't think we can expose those metrics through JMX/Ganglia/OpenTSDB as they
will be changing a lot. It would be "doable" only if the regions and families
never changed IMO. I'd prefer we concentrate on presenting this information
from inside HBase.
In the nice to haves I'd like to see:
- Number of accesses/misses per block or family (could see what's hot, well
cached, etc)
- Total size of the family on disk (then you can tell what portion of the
dataset you cached)
Regarding the Writable question, you have to do that because it's required by
Hadoop RPC. Since you are adding new infos, you'll have to implement it. Don't
forget the default constructor! :)
For the web UI, what about making the region name clickable?
> blockCache contents report
> --------------------------
>
> Key: HBASE-4089
> URL: https://issues.apache.org/jira/browse/HBASE-4089
> Project: HBase
> Issue Type: New Feature
> Reporter: Doug Meil
> Attachments: hbase_4089_blockcachereport.pdf
>
>
> Summarized block-cache report for a RegionServer would be helpful. For
> example ...
> table1
> cf1 100 blocks, totalBytes=yyyyy, averageTimeInCache=XXXX hours
> cf2 200 blocks, totalBytes=zzzzz, averageTimeInCache=XXXX hours
> table2
> cf1 75 blocks, totalBytes=yyyyy, averageTimeInCache=XXXX hours
> cf2 150 blocks, totalBytes=zzzzz, averageTimeInCache=XXXX hours
> ... Etc.
> The current metrics list blockCacheSize and blockCacheFree, but there is no
> way to know what's in there. Any single block isn't really important, but
> the patterns of what CF/Table they came from, how big are they, and how long
> (on average) they've been in the cache, are important.
> No such interface exists in HRegionInterface. But I think it would be
> helpful from an operational perspective.
> Updated (7-29): Removing suggestion for UI. I would be happy just to get
> this report on a configured interval dumped to a log file.
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