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https://issues.apache.org/jira/browse/HBASE-28405?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17834661#comment-17834661
]
Aman Poonia commented on HBASE-28405:
-------------------------------------
This is the fix i am testing currently
{code:java}
// code placeholder
diff --git
a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
index 813caa47d3..84f45a59a3 100644
---
a/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
+++
b/hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java
@@ -639,8 +639,27 @@ public class MergeTableRegionsProcedure
* Rollback close regions
**/
private void rollbackCloseRegionsForMerge(MasterProcedureEnv env) throws
IOException {
- AssignmentManagerUtil.reopenRegionsForRollback(env,
Arrays.asList(regionsToMerge),
- getRegionReplication(env), getServerName(env));
+ // At this point we should check if region was actually closed. If it was
not closed then we
+ // don't need to repoen the region and we can just change the regionNode
state to OPEN.
+ // if it is alredy closed then we need to do a reopen of region
+ ServerName serverName = getServerName(env);
+ List<RegionInfo> regionsOnServer =
env.getAssignmentManager().getRegionsOnServer(serverName);
+ List<RegionInfo> toAssign = new ArrayList<>();
+ for (RegionInfo rinfo : regionsToMerge) {
+ if (!regionsOnServer.contains(rinfo)) {
+ toAssign.add(rinfo);
+ } else {
+ // Change the region state to OPEN from MERGING
+ boolean success =
env.getAssignmentManager().getRegionStates().getRegionStateNode(rinfo)
+ .setState(State.OPEN, State.MERGING);
+ if (!success) {
+ LOG.warn("Region {} was not in expected state MERGING while rolling
back",
+ rinfo.getEncodedName());
+ }
+ }
+ }
+ AssignmentManagerUtil.reopenRegionsForRollback(env, toAssign,
getRegionReplication(env),
+ getServerName(env));
} private TransitRegionStateProcedure[]
createUnassignProcedures(MasterProcedureEnv env) {code}
The idea is that before we create TRSP we should check in rollback step if it
is needed for that particular region.
[~zhangduo] what do you think about this fix. here i am specifically fixing the
rollback part of failed merge and not trying to touch any other unnecessary
code.
[~vjasani] FYI
> Region open procedure silently returns without notifying the parent proc
> ------------------------------------------------------------------------
>
> Key: HBASE-28405
> URL: https://issues.apache.org/jira/browse/HBASE-28405
> Project: HBase
> Issue Type: Bug
> Components: proc-v2
> Affects Versions: 2.5.7
> Reporter: Aman Poonia
> Assignee: Aman Poonia
> Priority: Major
>
> *We had a scenario in production where a merge operation had failed as below*
> _2024-02-11 10:53:57,715 ERROR [PEWorker-31]
> assignment.MergeTableRegionsProcedure - Error trying to merge
> [a92008b76ccae47d55c590930b837036, f56752ae9f30fad9de5a80a8ba578e4b] in
> table1 (in state=MERGE_TABLE_REGIONS_CLOSE_REGIONS)_
> _org.apache.hadoop.hbase.HBaseIOException: The parent region state=MERGING,
> location=rs-229,60020,1707587658182, table=table1,
> region=f56752ae9f30fad9de5a80a8ba578e4b is currently in transition, give up_
> _at
> org.apache.hadoop.hbase.master.assignment.AssignmentManagerUtil.createUnassignProceduresForSplitOrMerge(AssignmentManagerUtil.java:120)_
> _at
> org.apache.hadoop.hbase.master.assignment.MergeTableRegionsProcedure.createUnassignProcedures(MergeTableRegionsProcedure.java:648)_
> _at
> org.apache.hadoop.hbase.master.assignment.MergeTableRegionsProcedure.executeFromState(MergeTableRegionsProcedure.java:205)_
> _at
> org.apache.hadoop.hbase.master.assignment.MergeTableRegionsProcedure.executeFromState(MergeTableRegionsProcedure.java:79)_
> _at
> org.apache.hadoop.hbase.procedure2.StateMachineProcedure.execute(StateMachineProcedure.java:188)_
> _at
> org.apache.hadoop.hbase.procedure2.Procedure.doExecute(Procedure.java:922)_
> _at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.execProcedure(ProcedureExecutor.java:1650)_
> _at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.executeProcedure(ProcedureExecutor.java:1396)_
> _at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor.access$1000(ProcedureExecutor.java:75)_
> _at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.runProcedure(ProcedureExecutor.java:1964)_
> _at org.apache.hadoop.hbase.trace.TraceUtil.trace(TraceUtil.java:216)_
> _at
> org.apache.hadoop.hbase.procedure2.ProcedureExecutor$WorkerThread.run(ProcedureExecutor.java:1991)_
> *Now when we do rollback of failed merge operation we see a issue where
> region is in state opened until the RS holding it stopped.*
> Rollback create a TRSP as below
> _2024-02-11 10:53:57,719 DEBUG [PEWorker-31] procedure2.ProcedureExecutor -
> Stored [pid=26674602,
> state=RUNNABLE:REGION_STATE_TRANSITION_GET_ASSIGN_CANDIDATE;
> TransitRegionStateProcedure table=table1,
> region=a92008b76ccae47d55c590930b837036, ASSIGN]_
> *and rollback finished successfully*
> _2024-02-11 10:53:57,721 INFO [PEWorker-31] procedure2.ProcedureExecutor -
> Rolled back pid=26673594, state=ROLLEDBACK,
> exception=org.apache.hadoop.hbase.HBaseIOException via
> master-merge-regions:org.apache.hadoop.hbase.HBaseIOException: The parent
> region state=MERGING, location=rs-229,60020,1707587658182, table=table1,
> region=f56752ae9f30fad9de5a80a8ba578e4b is currently in transition, give up;
> MergeTableRegionsProcedure table=table1,
> regions=[a92008b76ccae47d55c590930b837036, f56752ae9f30fad9de5a80a8ba578e4b],
> force=false exec-time=1.4820 sec_
> *We create a procedure to open the region a92008b76ccae47d55c590930b837036.
> Intrestingly we didnt close the region as creation of procedure to close
> regions had thrown exception and not execution of procedure. When we run TRSP
> it sends a OpenRegionProcedure which is handled by AssignRegionHandler. This
> handlers on execution suggests that region is already online*
> Sequence of events are as follow
> _2024-02-11 10:53:58,919 INFO [PEWorker-58] assignment.RegionStateStore -
> pid=26674602 updating hbase:meta row=a92008b76ccae47d55c590930b837036,
> regionState=OPENING, regionLocation=rs-210,60020,1707596461539_
> _2024-02-11 10:53:58,920 INFO [PEWorker-58] procedure2.ProcedureExecutor -
> Initialized subprocedures=[\\{pid=26675798, ppid=26674602, state=RUNNABLE;
> OpenRegionProcedure a92008b76ccae47d55c590930b837036,
> server=rs-210,60020,1707596461539}]_
> _2024-02-11 10:53:59,074 WARN [REGION-regionserver/rs-210:60020-10]
> handler.AssignRegionHandler - Received OPEN for
> table1,r1,1685436252488.a92008b76ccae47d55c590930b837036. which is already
> online_
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