tree dce5f0844ca505aebb7c43ecd8394da8c289d900
parent afb19a13d80ded592e05e7a89005ac661de503b2
author Hunter Lee <hulee@linkedin.com> 1572048076 -0700
committer Jiajun Wang <1803880+jiajunwang@users.noreply.github.com> 1581107062 -0800

Make WagedRebalancer static by creating a ThreadLocal (#540)

ZKBucketDataAccessor has a GC logic, but this is only valid if the ZkClient inside it is active and not closed. Currently, WAGED rebalancer generates an instance of AssignmentMetadataStore every time it rebalances, which does not allow the internal ZkBucketDataAccessor to garbage collect the assignment metadata it wrote previously.

This diff makes the entire WagedRebalancer object a ThreadLocal, which has the effect of making it essentially static across different runs of the pipeline.