RegionStates may has some expired serverinfo and make regions do not balance.

TransitRegionStateProcedure (open a region on a server) may run after the server have done ServerCrashProcedure. The ServerCrashProcedure will remove the ServerName entry from serverMap in RegionStates, but later the TransitRegionStateProcedure open a region on this server will add a entry in serverMap in RegionStates for this ServerName, the open will fail and retry, but serverMap in RegionStates leaves some expired ServerNames and have no chance to clear and it will make balance not correct.