[ 
https://issues.apache.org/jira/browse/HBASE-13965?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14622894#comment-14622894
 ] 

stack commented on HBASE-13965:
-------------------------------

bq. I think the ensemble table is more like a temporary table, and it is not in 
any namespace.

It is not a table at all -- smile. It is a key in a map usually keyed by 
tablename... it can be anything it looks like. So, put it in system namespace 
and then it won't clash with anyone or put it in an impossible namespace, 
'ephemeral'. See here for what is legal: 
http://grepcode.com/file/repo1.maven.org/maven2/org.apache.hbase/hbase-common/1.0.0/org/apache/hadoop/hbase/TableName.java#70

> Stochastic Load Balancer JMX Metrics
> ------------------------------------
>
>                 Key: HBASE-13965
>                 URL: https://issues.apache.org/jira/browse/HBASE-13965
>             Project: HBase
>          Issue Type: Improvement
>          Components: Balancer, metrics
>            Reporter: Lei Chen
>            Assignee: Lei Chen
>         Attachments: HBASE-13965-v3.patch, HBASE-13965-v4.patch, 
> HBASE-13965-v5.patch, HBASE-13965-v6.patch, HBASE-13965-v7.patch, 
> HBASE-13965_v2.patch, HBase-13965-v1.patch, 
> stochasticloadbalancerclasses_v2.png
>
>
> Today’s default HBase load balancer (the Stochastic load balancer) is cost 
> function based. The cost function weights are tunable but no visibility into 
> those cost function results is directly provided.
> A driving example is a cluster we have been tuning which has skewed rack size 
> (one rack has half the nodes of the other few racks). We are tuning the 
> cluster for uniform response time from all region servers with the ability to 
> tolerate a rack failure. Balancing LocalityCost, RegionReplicaRack Cost and 
> RegionCountSkew Cost is difficult without a way to attribute each cost 
> function’s contribution to overall cost. 
> What this jira proposes is to provide visibility via JMX into each cost 
> function of the stochastic load balancer, as well as the overall cost of the 
> balancing plan.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to