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https://issues.apache.org/jira/browse/HBASE-4608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13228108#comment-13228108
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Todd Lipcon commented on HBASE-4608:
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bq. First, compression ratio is not good - at least for the data written by PE.
I saw ~40% compression on a YCSB load. So some workloads may have good results 
whereas others didn't. Did you also re-run the test after fixing the bug? Maybe 
that skewed the results?

bq. Second, HLogKey persistence becomes dependent on the compression 
implementation. This would make plugging other compression techniques hard.
I agree we should use a metadata field in the log to describe which compression 
mechanism is being used.
                
> HLog Compression
> ----------------
>
>                 Key: HBASE-4608
>                 URL: https://issues.apache.org/jira/browse/HBASE-4608
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: Li Pi
>            Assignee: Li Pi
>             Fix For: 0.94.0
>
>         Attachments: 4608-v19.txt, 4608-v20.txt, 4608-v22.txt, 4608v1.txt, 
> 4608v13.txt, 4608v13.txt, 4608v14.txt, 4608v15.txt, 4608v16.txt, 4608v17.txt, 
> 4608v18.txt, 4608v5.txt, 4608v6.txt, 4608v7.txt, 4608v8fixed.txt
>
>
> The current bottleneck to HBase write speed is replicating the WAL appends 
> across different datanodes. We can speed up this process by compressing the 
> HLog. Current plan involves using a dictionary to compress table name, region 
> id, cf name, and possibly other bits of repeated data. Also, HLog format may 
> be changed in other ways to produce a smaller HLog.

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