[ 
https://issues.apache.org/jira/browse/HBASE-5489?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13220214#comment-13220214
 ] 

jirapos...@reviews.apache.org commented on HBASE-5489:
------------------------------------------------------


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/4117/
-----------------------------------------------------------

(Updated 2012-03-01 18:24:18.762517)


Review request for hbase.


Changes
-------

Made minor changes as per Stack's comments.


Summary
-------

getRegionsInRange() will retrieve the HRegionLocations for the regions 
associated with the specified key range, using client-side cache if possible.

I have one question: right now the endKey specified to getRegionsInRange() is 
treated as inclusive.  I followed the behavior that I saw in 
HRegionInfo.containsRange().  However, other HBase code such as Scan treats the 
endKey as exclusive.  So I am not clear as to which way we should go here.  I 
can easily change the patch if we want the endKey to be exclusive; please let 
me know.  Thanks in advance.


This addresses bug HBASE-5489.
    https://issues.apache.org/jira/browse/HBASE-5489


Diffs (updated)
-----

  src/main/java/org/apache/hadoop/hbase/client/HTable.java 29b8004 
  src/test/java/org/apache/hadoop/hbase/client/TestFromClientSide.java bdeaefe 

Diff: https://reviews.apache.org/r/4117/diff


Testing
-------

Ran the TestFromClientSide unit tests and passed repeatedly.

Ran test-patch.sh with the following results:

-1 overall.  

    +1 @author.  The patch does not contain any @author tags.

    +1 tests included.  The patch appears to include 3 new or modified tests.

    -1 javadoc.  The javadoc tool appears to have generated -129 warning 
messages.

    +1 javac.  The applied patch does not increase the total number of javac 
compiler warnings.

    +1 findbugs.  The patch does not introduce any new Findbugs (version ) 
warnings.

    +1 release audit.  The applied patch does not increase the total number of 
release audit warnings.


Thanks,

David


                
> Add HTable accessor to get regions for a key range
> --------------------------------------------------
>
>                 Key: HBASE-5489
>                 URL: https://issues.apache.org/jira/browse/HBASE-5489
>             Project: HBase
>          Issue Type: Improvement
>          Components: client
>            Reporter: David S. Wang
>            Assignee: David S. Wang
>            Priority: Minor
>             Fix For: 0.92.1, 0.94.0, 0.96.0
>
>         Attachments: HBASE-5489-2.patch, HBASE-5489-3.patch
>
>
> It would be nice to have an accessor to find all regions that overlap with a 
> particular range of keys. Right now, the only way to accomplish that is to 
> call HTable.getStartEndKeys(), then follow that with calls to 
> getRegionLocation() for the range of keys you are interested in.  This 
> algorithm has 2 drawbacks:
> * It returns more keys than is necessary most of the time.  This is 
> especially evident if there are a lot of regions comprising the table and the 
> range of keys is small.
> * It always does a scan of .META. via MetaScannerVisitor for at least 
> HTable.getStartEndKeys(), and perhaps for HRegionLocations that are not 
> already cached by the client.
> An accessor that limited its scans to a specified range could avoid scanning 
> .META. at all if the HRegionLocations being fetched were already cached by 
> the client, thereby potentially making this operation faster in common cases.
> Here's a proposal for the accessor:
>   /**
>    * Get the corresponding regions for an arbitrary range of keys.
>    * <p>
>    * @param startRow Starting row in range, inclusive
>    * @param endRow Ending row in range, inclusive
>    * @return A list of HRegionLocations corresponding to the regions that
>    * contain the specified range
>    * @throws IOException if a remote or network exception occurs
>    */
>   public List<HRegionLocation> getRegionsInRange(final byte [] startKey,
>     final byte [] endKey) throws IOException

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: 
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to