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https://issues.apache.org/jira/browse/HIVE-22420?focusedWorklogId=753288&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-753288
]
ASF GitHub Bot logged work on HIVE-22420:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 06/Apr/22 10:04
Start Date: 06/Apr/22 10:04
Worklog Time Spent: 10m
Work Description: pvary commented on code in PR #3181:
URL: https://github.com/apache/hive/pull/3181#discussion_r843750056
##########
ql/src/java/org/apache/hadoop/hive/ql/lockmgr/DbTxnManager.java:
##########
@@ -574,30 +571,24 @@ public void rollbackTxn() throws LockException {
if (!isTxnOpen()) {
throw new RuntimeException("Attempt to rollback before opening a
transaction");
}
- stopHeartbeat();
-
try {
- lockMgr.clearLocalLockRecords();
+ clearLocksAndHB();
LOG.debug("Rolling back " + JavaUtils.txnIdToString(txnId));
-
- // Re-checking as txn could have been closed, in the meantime, by a
competing thread.
- if (isTxnOpen()) {
- if (replPolicy != null) {
- getMS().replRollbackTxn(txnId, replPolicy, TxnType.DEFAULT);
- } else {
- getMS().rollbackTxn(txnId);
- }
+
+ if (replPolicy != null) {
Review Comment:
If we expect that this class should not be shared between threads, then we
should write a comment on the class level for it
Issue Time Tracking
-------------------
Worklog Id: (was: 753288)
Time Spent: 0.5h (was: 20m)
> DbTxnManager.stopHeartbeat() should be thread-safe
> --------------------------------------------------
>
> Key: HIVE-22420
> URL: https://issues.apache.org/jira/browse/HIVE-22420
> Project: Hive
> Issue Type: Bug
> Affects Versions: 3.1.0
> Reporter: Aron Hamvas
> Assignee: Aron Hamvas
> Priority: Major
> Labels: pull-request-available
> Fix For: 4.0.0, 4.0.0-alpha-1
>
> Attachments: HIVE-22420.1.patch, HIVE-22420.2.patch
>
> Time Spent: 0.5h
> Remaining Estimate: 0h
>
> When a transactional query is being executed and interrupted via HS2 close
> operation request, both the background pool thread executing the query and
> the HttpHandler thread running the close operation logic will eventually call
> the below method:
> {noformat}
> Driver.releaseLocksAndCommitOrRollback(commit boolean)
> {noformat}
> Since this method is invoked several times in both threads, it can happen
> that the two threads invoke it at the same time, and due to a race condition,
> the txnId field of the DbTxnManager used by both threads could be set to 0
> without actually successfully aborting the transaction.
> The root cause is stopHeartbeat() method in DbTxnManager not being thread
> safe:
> When Thread-1 and Thread-2 enter stopHeartbeat() with very little time
> difference, Thread-1 might successfully cancel the heartbeat task and set the
> heartbeatTask field to null, while Thread-2 is trying to observe its state.
> Thread-1 will return to the calling rollbackTxn() method and continue
> execution there, while Thread-2 wis thrown back to the same method with a
> NullPointerException. Thread-2 will then set txnId to 0, and Thread-1 is
> sending this 0 value to HMS. So, the txn will not be aborted, and the locks
> cannot be released later on either.
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