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https://issues.apache.org/jira/browse/HBASE-2021?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars George updated HBASE-2021:
-------------------------------

    Attachment: HBASE-2021.patch

HBASE-2021.patch adds

- compaction queue size to region server metrics, can be seen on 
regionserver.jsp

|Metrics | request=0.0, regions=3, stores=6, storefiles=3, 
storefileIndexSize=0, memstoreSize=0, compactionQueueSize=0, usedHeap=35, 
maxHeap=994, blockCacheSize=1713760, blockCacheFree=206913552, 
blockCacheCount=1, blockCacheHitRatio=95 | RegionServer Metrics; file and heap 
sizes are in megabytes |

The "compactionQueueSize" reflects the number of regions this regionserver has 
in the queue to be processed and allows to "determine" if compactions are in 
progress from the UI. 

I would have preferred to have a global indicator in the master UI but that 
value cannot be bubbled up unless I for example add it to HServerInfo - which I 
have been told is not a good idea to change. Right?

- Added fragmentation details to UI

Added a total fragmentation precentage to master.jsp in top table, for example:

| Regions On FS | 3 | Number of regions on FileSystem. Rough count. |
| Fragmentation | 17% | Overall fragmentation of all tables, including .META. 
and -ROOT-.|
|Zookeeper Quorum | localhost:2181 | Addresses of all registered ZK servers. 
For more, see zk dump.|

Then in the tables below for .META., -ROOT- and user table I added it as a 
column with an abbreviated title but added a pop-up explanation when you hover 
over it.



> Add compaction details to master UI
> -----------------------------------
>
>                 Key: HBASE-2021
>                 URL: https://issues.apache.org/jira/browse/HBASE-2021
>             Project: Hadoop HBase
>          Issue Type: Improvement
>            Reporter: Lars George
>            Assignee: Lars George
>            Priority: Minor
>         Attachments: HBASE-2021.patch
>
>
> There are two issues with this, first to detect that there is a compaction 
> needed. You can currently use the little helper util that checks if a table 
> has at least one colfam with more than one store file. I though about 
> scanning all tables and all colfams in each and then compute the 
> "fragmentation" ratio as a percentage of colfams with more than one store to 
> the total number of colfams. That gives a "Table xyz is 33% fragmented" 
> output. While minor percentage are normal under insert operations it is still 
> important to know how bad the fragmentation is overall.
> Another idea is to weigh the number of files per store too, so that if you 
> have two per colfam it is considered "low" and if you have more, for example 
> 6-8 it is considered "high". Not sure how that can be done yet but noting the 
> idea down here.
> Of course seeing the .META. fragmentation is useful to quickly debug 
> performance issues (as JD told me on IRC).
> The other issue is that when you have started a compaction you have no idea 
> how far it is and if it is still in progress. One indication of course is the 
> above value. If it is 0% then all is done. But if you are at say 23%, is it 
> still compacting? We could have a simple status that compactions are still in 
> progress.

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