tree 3803a2ffa3e4ea6ec90c761f5cf83198f0161695
parent 4c34be0639931a29074509b0e1cf9cee2495ec72
author jiajunwang <1803880+jiajunwang@users.noreply.github.com> 1564522892 -0700
committer Jiajun Wang <jjwang@jjwang-ld2.linkedin.biz> 1564687904 -0700

Fix the race condition while Helix refresh cluster status cache. (#363)

* Fix the race condition while Helix refresh cluster status cache.

This change fix issue #331.
The design is ensuring one read only to avoid locking during the change notification. However, a later update introduced addition read. The result is that two reads may have different results because notification is lock free. This leads the cache to be in an inconsistent state. The impact is that the expected rebalance might not happen.