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https://issues.apache.org/jira/browse/HBASE-13376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14699878#comment-14699878
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Ted Yu commented on HBASE-13376:
--------------------------------

For 0.98 patch, in StochasticLoadBalancer.java:
{code}
     protected int pickRandomRegion(Cluster cluster, int server, double 
chanceOfNoSwap) {
+      //TODO: Fix Ticket 7227684 which causes server to be -1.
{code}
The ticket refers to Yahoo internal ticket, right ?
Is the check for server being -1 still needed ?

The patch filename has underscore preceding 0.98
Not sure if QA bot can apply the patch on correct branch. Maybe change 
underscore to dash ?

> Improvements to Stochastic load balancer
> ----------------------------------------
>
>                 Key: HBASE-13376
>                 URL: https://issues.apache.org/jira/browse/HBASE-13376
>             Project: HBase
>          Issue Type: Improvement
>          Components: Balancer
>    Affects Versions: 1.0.0, 0.98.12
>            Reporter: Vandana Ayyalasomayajula
>            Assignee: Vandana Ayyalasomayajula
>            Priority: Minor
>             Fix For: 2.0.0, 1.3.0
>
>         Attachments: 13376-v2.txt, 13376-v5.patch, 13376_4.patch, 
> HBASE-13376.patch, HBASE-13376_0.98.txt, HBASE-13376_0.98_v2.patch, 
> HBASE-13376_0.txt, HBASE-13376_1.txt, HBASE-13376_1_1.txt, 
> HBASE-13376_2.patch, HBASE-13376_2_branch-1.patch, HBASE-13376_3.patch, 
> HBASE-13376_3.patch, HBASE-13376_4.patch, HBASE-13376_5_branch-1.patch, 
> HBASE-13376_6_branch-1.patch, HBASE-13376_98.patch, HBASE-13376_branch-1.patch
>
>
> There are two things this jira tries to address:
> 1. The locality picker in the stochastic balancer does not pick regions with 
> least locality as candidates for swap/move. So when any user configures 
> locality cost in the configs, the balancer does not always seems to move 
> regions with bad locality. 
> 2. When a cluster has equal number of loaded regions, it always picks the 
> first one. It should pick a random region on one of the equally loaded 
> servers. This improves a chance of finding a good candidate, when load picker 
> is invoked several times. 



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