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Lei Chen commented on HBASE-13965: ---------------------------------- Yes, sounds good, since the full list of cost functions should be known to the user. > 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_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)