Stephen Yuan Jiang created HBASE-17238:
------------------------------------------
Summary: Wrong in-memory hbase:meta location causing SSH failure
Key: HBASE-17238
URL: https://issues.apache.org/jira/browse/HBASE-17238
Project: HBase
Issue Type: Bug
Components: Region Assignment
Affects Versions: 1.1.0
Reporter: Stephen Yuan Jiang
Assignee: Stephen Yuan Jiang
Priority: Critical
In HBase 1.x, if HMaster#assignMeta() assigns a non-DEFAULT_REPLICA_ID
hbase:meta region, it would wrongly update the DEFAULT_REPLICA_ID hbase:meta
region in-memory. This caused the in-memory region state has wrong RS
information for default replica hbase:meta region. One of the problem we saw
is a wrong type of SSH could be chosen and causing problems.
{code}
void assignMeta(MonitoredTask status, Set<ServerName> previouslyFailedMetaRSs,
int replicaId)
throws InterruptedException, IOException, KeeperException {
// Work on meta region
...
if (replicaId == HRegionInfo.DEFAULT_REPLICA_ID) {
status.setStatus("Assigning hbase:meta region");
} else {
status.setStatus("Assigning hbase:meta region, replicaId " + replicaId);
}
// Get current meta state from zk.
RegionStates regionStates = assignmentManager.getRegionStates();
RegionState metaState = MetaTableLocator.getMetaRegionState(getZooKeeper(),
replicaId);
HRegionInfo hri =
RegionReplicaUtil.getRegionInfoForReplica(HRegionInfo.FIRST_META_REGIONINFO,
replicaId);
ServerName currentMetaServer = metaState.getServerName();
...
boolean rit = this.assignmentManager.
processRegionInTransitionAndBlockUntilAssigned(hri);
boolean metaRegionLocation = metaTableLocator.verifyMetaRegionLocation(
this.getConnection(), this.getZooKeeper(), timeout, replicaId);
...
} else {
// Region already assigned. We didn't assign it. Add to in-memory state.
regionStates.updateRegionState(
HRegionInfo.FIRST_META_REGIONINFO, State.OPEN, currentMetaServer);
<<--- Wrong region to update -->>
this.assignmentManager.regionOnline(
HRegionInfo.FIRST_META_REGIONINFO, currentMetaServer); <<--- Wrong
region to update -->>
}
...
{code}
Here is the problem scenario:
Step 1: master failovers (or starts could have the same issue) and find default
replica of hbase:meta is in rs1.
{noformat}
2016-11-26 00:06:36,590 INFO org.apache.hadoop.hbase.master.ServerManager:
AssignmentManager hasn't finished failover cleanup; waiting
2016-11-26 00:06:36,591 INFO org.apache.hadoop.hbase.master.HMaster: hbase:meta
with replicaId 0 assigned=0, rit=false, location=rs1,60200,1480103147220
{noformat}
Step 2: master finds that replica 1 of hbase:meta is unassigned, therefore,
HMaster#assignMeta() is called and assign the replica 1 region to rs2, but at
the end, it wrongly updates the in-memory state of default replica to rs2
{noformat}
2016-11-26 00:08:21,741 DEBUG org.apache.hadoop.hbase.master.RegionStates:
Onlined 1588230740 on rs2,60200,1480102993815 {ENCODED => 1588230740, NAME =>
'hbase:meta,,1', STARTKEY => '', ENDKEY => ''}
2016-11-26 00:08:21,741 INFO org.apache.hadoop.hbase.master.RegionStates:
Offlined 1588230740 from rs1,60200,1480103147220
2016-11-26 00:08:21,741 INFO org.apache.hadoop.hbase.master.HMaster: hbase:meta
with replicaId 1 assigned=0, rit=false, location=rs2,60200,1480102993815
{noformat}
Step 3: now rs1 is down, master needs to choose which SSH to call
(MetaServerShutdownHandler or normal ServerShutdownHandler) - in this case,
MetaServerShutdownHandler should be chosen; however, due to wrong in-memory
location, normal ServerShutdownHandler was chosen:
{noformat}
2016-11-26 00:08:33,995 INFO
org.apache.hadoop.hbase.zookeeper.RegionServerTracker: RegionServer ephemeral
node deleted, processing expiration [rs1,60200,1480103147220]
2016-11-26 00:08:33,998 DEBUG org.apache.hadoop.hbase.master.AssignmentManager:
based on AM, current region=hbase:meta,,1.1588230740 is on
server=rs2,60200,1480102993815 server being checked: rs1,60200,1480103147220
2016-11-26 00:08:34,001 DEBUG org.apache.hadoop.hbase.master.ServerManager:
Added=rs1,60200,1480103147220 to dead servers, submitted shutdown handler to be
executed meta=false
{noformat}
Step 4: Wrong SSH was chosen. Due to accessing hbase:meta failure, the SSH
failed after retries. Now the dead server was not processed; regions in that
server remains un-usable (We have a solution that resolve this issue, but is
undesirable: restarting master to cleanup the wrong in-memory state would make
this problem go away):
{noformat}
2016-11-26 00:11:46,550 INFO
org.apache.hadoop.hbase.master.handler.ServerShutdownHandler: Received
exception accessing hbase:meta during server shutdown of
rs1,60200,1480103147220, retrying hbase:meta read
org.apache.hadoop.hbase.client.RetriesExhaustedException: Failed after
attempts=351, exceptions:
Sat Nov 26 00:11:46 EST 2016, null, java.net.SocketTimeoutException:
callTimeout=60000, callDuration=68188: row '' on table 'hbase:meta' at
region=hbase:meta,,1.1588230740, hostname=rs1,60200,1480103147220, seqNum=0
at
org.apache.hadoop.hbase.client.RpcRetryingCallerWithReadReplicas.throwEnrichedException(RpcRetryingCallerWithReadReplicas.java:271)
at
org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:203)
at
org.apache.hadoop.hbase.client.ScannerCallableWithReplicas.call(ScannerCallableWithReplicas.java:60)
at
org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
at
org.apache.hadoop.hbase.client.ClientScanner.call(ClientScanner.java:320)
at
org.apache.hadoop.hbase.client.ClientScanner.nextScanner(ClientScanner.java:295)
at
org.apache.hadoop.hbase.client.ClientScanner.initializeScannerInConstruction(ClientScanner.java:160)
at
org.apache.hadoop.hbase.client.ClientScanner.<init>(ClientScanner.java:155)
at org.apache.hadoop.hbase.client.HTable.getScanner(HTable.java:794)
at
org.apache.hadoop.hbase.MetaTableAccessor.fullScan(MetaTableAccessor.java:602)
at
org.apache.hadoop.hbase.MetaTableAccessor.fullScan(MetaTableAccessor.java:156)
at
org.apache.hadoop.hbase.MetaTableAccessor.getServerUserRegions(MetaTableAccessor.java:555)
at
org.apache.hadoop.hbase.master.handler.ServerShutdownHandler.process(ServerShutdownHandler.java:177)
at
org.apache.hadoop.hbase.executor.EventHandler.run(EventHandler.java:129)
at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.net.SocketTimeoutException: callTimeout=60000,
callDuration=68188: row '' on table 'hbase:meta' at
region=hbase:meta,,1.1588230740, hostname=rs1,60200,1480103147220, seqNum=0
at
org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:159)
at
org.apache.hadoop.hbase.client.ResultBoundedCompletionService$QueueingFuture.run(ResultBoundedCompletionService.java:65)
... 3 more
Caused by: java.io.IOException: Call to rs1/123.45.67.890:60200 failed on local
exception: org.apache.hadoop.hbase.ipc.FailedServerException: This server is in
the failed servers list: rs1/123.45.67.890:60200
at
org.apache.hadoop.hbase.ipc.RpcClientImpl.wrapException(RpcClientImpl.java:1261)
at
org.apache.hadoop.hbase.ipc.RpcClientImpl.call(RpcClientImpl.java:1229)
at
org.apache.hadoop.hbase.ipc.AbstractRpcClient.callBlockingMethod(AbstractRpcClient.java:213)
at
org.apache.hadoop.hbase.ipc.AbstractRpcClient$BlockingRpcChannelImplementation.callBlockingMethod(AbstractRpcClient.java:287)
at
org.apache.hadoop.hbase.protobuf.generated.ClientProtos$ClientService$BlockingStub.scan(ClientProtos.java:32651)
at
org.apache.hadoop.hbase.client.ScannerCallable.openScanner(ScannerCallable.java:372)
at
org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:199)
at
org.apache.hadoop.hbase.client.ScannerCallable.call(ScannerCallable.java:62)
at
org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithoutRetries(RpcRetryingCaller.java:200)
at
org.apache.hadoop.hbase.client.ScannerCallableWithReplicas$RetryingRPC.call(ScannerCallableWithReplicas.java:356)
at
org.apache.hadoop.hbase.client.ScannerCallableWithReplicas$RetryingRPC.call(ScannerCallableWithReplicas.java:330)
at
org.apache.hadoop.hbase.client.RpcRetryingCaller.callWithRetries(RpcRetryingCaller.java:126)
... 4 more
Caused by: org.apache.hadoop.hbase.ipc.FailedServerException: This server is in
the failed servers list: rs1/123.45.67.890:60200
at
org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection.setupIOstreams(RpcClientImpl.java:701)
at
org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection.writeRequest(RpcClientImpl.java:887)
at
org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection.tracedWriteRequest(RpcClientImpl.java:856)
at
org.apache.hadoop.hbase.ipc.RpcClientImpl$Connection$CallSender.run(RpcClientImpl.java:266)
{noformat}
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