Affects Version/s: 0.90.4
Fix Version/s: 0.90.5
As suggested by Stack in
HBASE-4217 creating a new issue to provide a patch for 0.90.x version.
We had some sort of an outage this morning due to a few racks losing power, and some regions were left in the following state:
ERROR: Region UNKNOWN_REGION on sv4r17s9:60020, key=e32bbe1f48c9b3633c557dc0291b90a3, not on HDFS or in META but deployed on sv4r17s9:60020
That region was deleted by the master but the region server never got the memo. Right now there's no way to force close it because HRS.closeRegion requires an HRI and the only way to create one is to get it from .META. which in our case doesn't contain a row for that region. Basically we have to wait until that server is dead to get rid of the region and make hbck happy.
The required change is to have closeRegion accept an encoded name in both HBA (when the RS address is provided) and HRS since it's able to find it anyways from it's list of live regions.
If a 0.90 version, we maybe should do that in another issue.