[
https://issues.apache.org/jira/browse/HBASE-21344?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16658410#comment-16658410
]
stack commented on HBASE-21344:
-------------------------------
bq. Here actually, we are correcting the rollback of assign procedure for Meta
in both IMP and SCP.
Do you mean roll back of AssignProcedure? (IMP has one step, making an
AssignProcedure as subprocedure for meta). Rollback and AP don't really go
together; AP doesn't support Rollback.
When you say...
bq. Earlier, rollback of assign corrects the meta region node(by moving it to
offline state)
To what are you referring? Looking in AP and SCP, there is no rollback -- but
you are referring to a specific location. Looking at patch, it looks like you
are working in AP#FAILED_OPEN.
If so, your changes in here look good... I wonder about this one though:
400 try {
401 handleFailure(env, regionNode);
402 } catch (IOException e) {
403 return false;
404 }
Previous we'd let out IOEs now you are catching them and converting them to
false. Maybe catch more local to undoRegionAsOpening since this is new source
of IOE.
I think this addition of yours looks good down here in undoRegionAsOpening.
Did you change decrementMinRegionServerCount to public for tests? If so, add
@VisibleForTesting... annotation sir.
Let me get back to you after I study your tests more. They look good.
bq. Do you think scheduling IMP without checking whether meta logs were split
or not, will cause in any problem?
Yes. Philosophy is that all recovery is done via SCP since it has the means for
splitting WALs (or figuring this step can be skipped).
bq. HBASE-21035 looks quite similar but it seems that the handling is more
related to the case where the procedures WALs is accidentally/ intentionally
cleared.
That is correct..... but the general practice suggested is that when unsure,
then for now at least, we fall back to operator intervention.
Please be patient with me Ankit. I'm generally slow. It takes me a while to
understand. Thanks for the help.
> hbase:meta location in ZooKeeper set to OPENING by the procedure which
> eventually failed but precludes Master from assigning it forever
> ---------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-21344
> URL: https://issues.apache.org/jira/browse/HBASE-21344
> Project: HBase
> Issue Type: Bug
> Components: proc-v2
> Reporter: Ankit Singhal
> Assignee: Ankit Singhal
> Priority: Major
> Attachments: HBASE-21344-branch-2.0.patch
>
>
> [~elserj] has already summarized it well.
> 1. hbase:meta was on RS8
> 2. RS8 crashed, SCP was queued for it, meta first
> 3. meta was marked OFFLINE
> 4. meta marked as OPENING on RS3
> 5. Can't actually send the openRegion RPC to RS3 due to the krb ticket issue
> 6. We attempt the openRegion/assignment 10 times, failing each time
> 7. We start rolling back the procedure:
> {code:java}
> 2018-10-08 06:51:24,440 WARN [PEWorker-9] procedure2.ProcedureExecutor:
> Usually this should not happen, we will release the lock before if the
> procedure is finished, even if the holdLock is true, arrive here means we
> have some holes where we do not release the lock. And the releaseLock below
> may fail since the procedure may have already been deleted from the procedure
> store.
> 2018-10-08 06:51:24,543 INFO [PEWorker-9]
> procedure.MasterProcedureScheduler: pid=48, ppid=47,
> state=FAILED:REGION_TRANSITION_QUEUE,
> exception=org.apache.hadoop.hbase.client.RetriesExhaustedException via
> AssignProcedure:org.apache.hadoop.hbase.client.RetriesExhaustedException: Max
> attempts exceeded; AssignProcedure table=hbase:meta, region=1588230740
> checking lock on 1588230740
> {code}
> {code:java}
> 2018-10-08 06:51:30,957 ERROR [PEWorker-9] procedure2.ProcedureExecutor:
> CODE-BUG: Uncaught runtime exception for pid=47,
> state=FAILED:SERVER_CRASH_ASSIGN_META, locked=true,
> exception=org.apache.hadoop.hbase.client.RetriesExhaustedException via
> AssignProcedure:org.apache.hadoop.hbase.client.RetriesExhaustedException: Max
> attempts exceeded; ServerCrashProcedure
> server=<ip-address>,16020,1538974612843, splitWal=true, meta=true
> java.lang.UnsupportedOperationException: unhandled
> state=SERVER_CRASH_GET_REGIONS
> at
> org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure.rollbackState(ServerCrashProcedure.java:254)
> at
> org.apache.hadoop.hbase.master.procedure.ServerCrashProcedure.rollbackState(ServerCrashProcedure.java:58)
> at
> org.apache.hadoop.hbase.procedure2.StateMachineProcedure.rollback(StateMachineProcedure.java:203)
> at
> org.apache.hadoop.hbase.procedure2.Procedure.doRollback(Procedure.java:960)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeRollback(ProcedureExecutor.java:1577)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeRollback(ProcedureExecutor.java:1539)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeProcedure(ProcedureExecutor.java:1418)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.access$900(ProcedureExecutor.java:75)
> at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.run(ProcedureExecutor.java:1981)
> {code}
> {code:java}
> { DEBUG [PEWorker-2] client.RpcRetryingCallerImpl: Call exception, tries=7,
> retries=7, started=8168 ms ago, cancelled=false, msg=Meta region is in state
> OPENING, details=row 'backup:system' on table 'hbase:meta' at
> region=hbase:meta,,1.1588230740, hostname=<hostname>, seqNum=-1,
> exception=java.io.IOException: Meta region is in state OPENING
> at
> org.apache.hadoop.hbase.client.ZKAsyncRegistry.lambda$null$1(ZKAsyncRegistry.java:154)
> at
> java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
> at
> java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
> at
> java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
> at
> java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
> at
> org.apache.hadoop.hbase.client.ZKAsyncRegistry.lambda$getAndConvert$0(ZKAsyncRegistry.java:77)
> at
> java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:760)
> at
> java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:736)
> at
> java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:474)
> at
> java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1962)
> at
> org.apache.hadoop.hbase.zookeeper.ReadOnlyZKClient$ZKTask$1.exec(ReadOnlyZKClient.java:165)
> at
> org.apache.hadoop.hbase.zookeeper.ReadOnlyZKClient.run(ReadOnlyZKClient.java:323)
> at java.lang.Thread.run(Thread.java:748)
> {code}
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
