The Problem about GetRegion

[Tangruilin]

In lab3b, we meet a confusing problem. In TestSplitConfChangeSnapshotUnreliableRecoverConcurrentPartition3B, we will sometimes meet no region. There is such a case, the oldRegion is splitted, but the newRgion now doesn't have a Leader, then the PD won't know the info of newRegion. If a getRegion msg is sent at that time, it may reply no region. The sleep time of your code is 20ms, but many students' computer may not perform well enough.

[Tangruilin]

We change the sleep time to 50ms then it does not appear now, but I think you may let PD know the region while starting it but not the heartbeat.

[Connor1996]

"let PD know the region while starting it but not the heartbeat" that's what your impl should consider