Details
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Bug
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Status: Reopened
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Major
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Resolution: Unresolved
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3.0.0-alpha-1, 2.2.0
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None
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None
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Reviewed
Description
It's a classic bug, sort of... the call times out to open the region, but RS actually processes it alright. It could also happen if the response didn't make it back due to a network issue.
As a result region is opened on two servers.
There are some mitigations possible to narrow down the race window.
1) Don't process expired open calls, fail them. Won't help for network issues.
2) Don't ignore invalid RS state, kill it (YouAreDead exception) - but that will require fixing other network races where master kills RS, which would require adding state versioning to the protocol.
The fundamental fix though would require either
1) an unknown failure from open to ascertain the state of the region from the server. Again, this would probably require protocol changes to make sure we ascertain the region is not opened, and also that the already-failed-on-master open is NOT going to be processed if it's some queue or even in transit on the network (via a nonce-like mechanism)?
2) some form of a distributed lock per region, e.g. in ZK
3) some form of 2PC? but the participant list cannot be determined in a manner that's both scalable and guaranteed correct. Theoretically it could be all RSes.
2019-02-08 03:21:31,715 INFO [PEWorker-7] procedure.MasterProcedureScheduler: Took xlock for pid=260626, ppid=260595, state=RUNNABLE:REGION_STATE_TRANSITION_GET_ASSIGN_CANDIDATE, hasLock=false; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN
2019-02-08 03:21:31,758 INFO [PEWorker-7] assignment.TransitRegionStateProcedure: Starting pid=260626, ppid=260595, state=RUNNABLE:REGION_STATE_TRANSITION_GET_ASSIGN_CANDIDATE, hasLock=true; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN; rit=OPEN, location=server1,17020,1549567999303; forceNewPlan=false, retain=true
2019-02-08 03:21:31,984 INFO [PEWorker-13] assignment.RegionStateStore: pid=260626 updating hbase:meta row=d0214809147e43dc6870005742d5d204, regionState=OPENING, regionLocation=server1,17020,1549623714617
2019-02-08 03:22:32,552 WARN [RSProcedureDispatcher-pool4-t3451] assignment.RegionRemoteProcedureBase: The remote operation pid=260637, ppid=260626, state=RUNNABLE, hasLock=false; org.apache.hadoop.hbase.master.assignment.OpenRegionProcedure for region ... to server server1,17020,1549623714617 failed
java.io.IOException: Call to server1/...:17020 failed on local exception: org.apache.hadoop.hbase.ipc.CallTimeoutException: Call id=27191, waitTime=60145, rpcTimeout=60000^M
at org.apache.hadoop.hbase.ipc.IPCUtil.wrapException(IPCUtil.java:185)^M
at org.apache.hadoop.hbase.ipc.AbstractRpcClient.onCallFinished(AbstractRpcClient.java:391)^M
...
Caused by: org.apache.hadoop.hbase.ipc.CallTimeoutException: Call id=27191, waitTime=60145, rpcTimeout=60000^M
at org.apache.hadoop.hbase.ipc.RpcConnection$1.run(RpcConnection.java:200)^M
... 4 more^M
RS:
hbase-regionserver.log:2019-02-08 03:22:41,131 INFO [RS_OPEN_REGION-regionserver/server1:17020-2] handler.AssignRegionHandler: Open ...d0214809147e43dc6870005742d5d204. ... hbase-regionserver.log:2019-02-08 03:25:44,751 INFO [RS_OPEN_REGION-regionserver/server1:17020-2] handler.AssignRegionHandler: Opened ...d0214809147e43dc6870005742d5d204.
Retry:
2019-02-08 03:22:32,967 INFO [PEWorker-6] assignment.TransitRegionStateProcedure: Retry=1 of max=2147483647; pid=260626, ppid=260595, state=RUNNABLE:REGION_STATE_TRANSITION_CONFIRM_OPENED, hasLock=true; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN; rit=OPENING, location=server1,17020,1549623714617 2019-02-08 03:22:33,084 INFO [PEWorker-6] assignment.TransitRegionStateProcedure: Starting pid=260626, ppid=260595, state=RUNNABLE:REGION_STATE_TRANSITION_GET_ASSIGN_CANDIDATE, hasLock=true; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN; rit=OPENING, location=null; forceNewPlan=true, retain=false 2019-02-08 03:22:33,238 INFO [PEWorker-7] assignment.RegionStateStore: pid=260626 updating hbase:meta row=d0214809147e43dc6870005742d5d204, regionState=OPENING, regionLocation=server2,17020,1549569075319
The ignore-message
2019-02-08 03:25:44,754 WARN [RpcServer.default.FPBQ.Fifo.handler=34,queue=4,port=17000] assignment.TransitRegionStateProcedure: Received report OPENED transition from server1,17020,1549623714617 for rit=OPENING, location=server2,17020,1549569075319, table=table, region=d0214809147e43dc6870005742d5d204, pid=260626 but the region is not on it, should be a retry, ignore
The 2nd assignment
2019-02-08 03:26:18,915 INFO [PEWorker-7] procedure2.ProcedureExecutor: Finished subprocedure(s) of pid=260626, ppid=260595, state=RUNNABLE:REGION_STATE_TRANSITION_CONFIRM_OPENED, hasLock=true; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN; resume parent processing. 2019-02-08 03:26:18,971 INFO [PEWorker-11] procedure2.ProcedureExecutor: Finished pid=260626, ppid=260595, state=SUCCESS, hasLock=false; TransitRegionStateProcedure table=table, region=d0214809147e43dc6870005742d5d204, ASSIGN in 4mins, 47.347sec
======= by Duo Zhang ======
The actual problem here is that, in IPCUtil.wrapException, we want to add the remote server address in the exception message so it will be easier for debugging, and there are several instanceof checks in it which is for keeping the original exception type, since upper layer may depend on the exception type for error recovery. But we do not check for CallTimeoutException in this method so it will be wrapped by an IOException, which makes the code in RSProcedureDispatcher broken, and causes the double assign.
Attachments
Attachments
Issue Links
- is a clone of
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- Resolved
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- is related to
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HBASE-21876 Kill the region server if we can not send request to it for a long time in RSProcedureDispatcher
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- Open
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