Adds region state check on hbck2 assigns/unassigns. Returns pid of -1
if in inappropriate state with logging explaination which suggests
passing override if operator wants to assign/unassign anyways. Here
is an example of what happens now if hbck2 tries an unassign and
Region already unassigned:
2020-08-19 11:22:06,926 INFO [RpcServer.default.FPBQ.Fifo.handler=1,queue=0,port=50086] assignment.AssignmentManager(820): Failed {ENCODED => d1112e553991e938b6852f87774c91ee, NAME => 'TestHbck,zzzzz,1597861310769.d1112e553991e938b6852f87774c91ee.', STARTKEY => 'zzzzz', ENDKEY => ''} unassign, override=false; set override to by-pass state checks.
org.apache.hadoop.hbase.client.DoNotRetryRegionException: Unexpected state for state=CLOSED, location=null, table=TestHbck, region=d1112e553991e938b6852f87774c91ee
at org.apache.hadoop.hbase.master.assignment.AssignmentManager.preTransitCheck(AssignmentManager.java:583)
at org.apache.hadoop.hbase.master.assignment.AssignmentManager.createOneUnassignProcedure(AssignmentManager.java:812)
at org.apache.hadoop.hbase.master.MasterRpcServices.unassigns(MasterRpcServices.java:2616)
at org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos$HbckService$2.callBlockingMethod(MasterProtos.java)
at org.apache.hadoop.hbase.ipc.RpcServer.call(RpcServer.java:397)
at org.apache.hadoop.hbase.ipc.CallRunner.run(CallRunner.java:133)
at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:338)
at org.apache.hadoop.hbase.ipc.RpcExecutor$Handler.run(RpcExecutor.java:318)
Previous it would just create the unassign anyways. Now must pass override
to queue the procedure regardless. Safer.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java
javadoc on assigns/unassigns. Minor refactor in assigns/unassigns to cater to
case where procedure may come back null (if override not set and fails state checks).
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/AssignmentManager.java
checkstyle cleanups.
Clarifying javadoc on how there is no state checking when bulk assigns creating/enabling
tables.
createOneAssignProcedure and createOneUnassignProcedure now handle exceptions which now
can be thrown if no override and region state is not appropriate.
Aggregation of createAssignProcedure and createUnassignProcedure instances adding in
region state check invoked if override is NOT set.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/RegionStateNode.java
Change to setProcedure so it returns passed proc as result instead of void
Signed-off-by: Duo Zhang <zhangduo@apache.org>