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https://issues.apache.org/jira/browse/HBASE-13965?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14609390#comment-14609390
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Enis Soztutar commented on HBASE-13965:
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Thanks Lei for the patch. Looks good overall. A couple of feedback items:
- Can you create the patch so that it is a one commit. Current stacked patch
is not reviewable. See https://hbase.apache.org/book.html#submitting.patches
- As per Stack, please only include changes needed for the patch. {{conf/}}
and some others are not needed.
- We usually use: {{(name != null)}} rather than {{(null != name)}}
- This map is ever growing:
{code}
+ Map<String, Map<String, Double>> stochasticCosts =
{code}
In a dynamic cluster where tables are short lived, it can cause OOM. Not sure
whether there is an easy way to phase out stuff from that map.
> 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-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.
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