zk1931/jzab — pull request #155 by EasonLiao (2014-10-03 00:11:32+00:00)
Title: The cluster gets blocked while somebody is joining

This happens when cluster size gets changed from 1 to 2. Since the new joined guy takes some time for synchronization, so all the transactions after COP get blocked until the new joined server gets synchronized.

Solve this by doing 2-phase synchronization.