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https://issues.apache.org/jira/browse/HBASE-14326?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14952739#comment-14952739
 ] 

Hadoop QA commented on HBASE-14326:
-----------------------------------

{color:red}-1 overall{color}.  Here are the results of testing the latest 
attachment 
  http://issues.apache.org/jira/secure/attachment/12766056/HBASE-14326.patch
  against master branch at commit 587f5bc11f9d5d37557baf36c7df110af860a95c.
  ATTACHMENT ID: 12766056

    {color:green}+1 @author{color}.  The patch does not contain any @author 
tags.

    {color:green}+0 tests included{color}.  The patch appears to be a 
documentation patch that doesn't require tests.

    {color:green}+1 hadoop versions{color}. The patch compiles with all 
supported hadoop versions (2.4.0 2.4.1 2.5.0 2.5.1 2.5.2 2.6.0 2.6.1 2.7.0 
2.7.1)

    {color:green}+1 javac{color}.  The applied patch does not increase the 
total number of javac compiler warnings.

    {color:green}+1 protoc{color}.  The applied patch does not increase the 
total number of protoc compiler warnings.

    {color:green}+1 javadoc{color}.  The javadoc tool did not generate any 
warning messages.

    {color:green}+1 checkstyle{color}.  The applied patch does not increase the 
total number of checkstyle errors

    {color:red}-1 findbugs{color}.  The patch appears to cause Findbugs 
(version 2.0.3) to fail.

    {color:green}+1 release audit{color}.  The applied patch does not increase 
the total number of release audit warnings.

    {color:green}+1 lineLengths{color}.  The patch does not introduce lines 
longer than 100

  {color:green}+1 site{color}.  The mvn post-site goal succeeds with this patch.

    {color:green}+1 core tests{color}.  The patch passed unit tests in .

Test results: 
https://builds.apache.org/job/PreCommit-HBASE-Build/15959//testReport/
Checkstyle Errors: 
https://builds.apache.org/job/PreCommit-HBASE-Build/15959//artifact/patchprocess/checkstyle-aggregate.html

  Console output: 
https://builds.apache.org/job/PreCommit-HBASE-Build/15959//console

This message is automatically generated.

> HBase book: fix definition of max min size to compact
> -----------------------------------------------------
>
>                 Key: HBASE-14326
>                 URL: https://issues.apache.org/jira/browse/HBASE-14326
>             Project: HBase
>          Issue Type: Bug
>          Components: documentation
>            Reporter: Vladimir Rodionov
>            Assignee: Misty Stanley-Jones
>             Fix For: 2.0.0
>
>         Attachments: HBASE-14326.patch
>
>
> I think we need to change wording/definition of these config parameters in 
> HBase book, they are misleading:
> {quote}
> hbase.hstore.compaction.min.size
> Description
> A StoreFile smaller than this size will always be eligible for minor 
> compaction. HFiles this size or larger are evaluated by 
> hbase.hstore.compaction.ratio to determine if they are eligible. Because this 
> limit represents the "automatic include"limit for all StoreFiles smaller than 
> this value, this value may need to be reduced in write-heavy environments 
> where many StoreFiles in the 1-2 MB range are being flushed, because every 
> StoreFile will be targeted for compaction and the resulting StoreFiles may 
> still be under the minimum size and require further compaction. If this 
> parameter is lowered, the ratio check is triggered more quickly. This 
> addressed some issues seen in earlier versions of HBase but changing this 
> parameter is no longer necessary in most situations. Default: 128 MB 
> expressed in bytes.
> Default
> 134217728
> hbase.hstore.compaction.max.size
> Description
> A StoreFile larger than this size will be excluded from compaction. The 
> effect of raising hbase.hstore.compaction.max.size is fewer, larger 
> StoreFiles that do not get compacted often. If you feel that compaction is 
> happening too often without much benefit, you can try raising this value. 
> Default: the value of LONG.MAX_VALUE, expressed in bytes.
> hbase.hstore.compaction.ratio
> Description
> For minor compaction, this ratio is used to determine whether a given 
> StoreFile which is larger than hbase.hstore.compaction.min.size is eligible 
> for compaction. Its effect is to limit compaction of large StoreFiles. The 
> value of hbase.hstore.compaction.ratio is expressed as a floating-point 
> decimal. A large ratio, such as 10, will produce a single giant StoreFile. 
> Conversely, a low value, such as .25, will produce behavior similar to the 
> BigTable compaction algorithm, producing four StoreFiles. A moderate value of 
> between 1.0 and 1.4 is recommended. When tuning this value, you are balancing 
> write costs with read costs. Raising the value (to something like 1.4) will 
> have more write costs, because you will compact larger StoreFiles. However, 
> during reads, HBase will need to seek through fewer StoreFiles to accomplish 
> the read. Consider this approach if you cannot take advantage of Bloom 
> filters. Otherwise, you can lower this value to something like 1.0 to reduce 
> the background cost of writes, and use Bloom filters to control the number of 
> StoreFiles touched during reads. For most cases, the default value is 
> appropriate.
> Default
> 1.2F
> {quote}
> For details, see HBASE-14263.



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