[HBASE-23153] PrimaryRegionCountSkewCostFunction SLB function should implement CostFunction#isNeeded

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha-1, 2.3.0, 1.6.0, 1.4.11, 2.2.2, 2.1.8
• Hadoop Flags: Reviewed

Release Note

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The `PrimaryRegionCountSkewCostFunction` for the `StochasticLoadBalancer` is only needed when the read replicas feature is enabled. With this change, that function now properly indicates that it is not needed when the read replica feature is off.

If this improvement is not available, operators with clusters that are not using the read replica feature should manually disable it by setting `hbase.master.balancer.stochastic.primaryRegionCountCost` to `0.0` in hbase-site.xml for all HBase Masters.

• Assignee: Andrew Kyle Purtell
• Reporter: Andrew Kyle Purtell
• Created: 12/Oct/19 00:33
• Updated: 08/Apr/20 12:46
• Resolved: 08/Apr/20 12:46

Description

The PrimaryRegionCountSkewCostFunction SLB function should implement CostFunction#isNeeded and like the other region replica specific functions should return false for it when region replicas are not in use. Otherwise it will always report a cost of 0 even though its weight will be included in the sum of the weights.

Issue Links

• links to: GitHub Pull Request #714