HIVE-28669: Deadlock found when TxnStoreMutex trying to acquireLock #5585
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
|
Based on the comments on JIRA and I have tested this patch on my local and haven't seen the error stacktrace, hence |
| @@ -174,16 +174,13 @@ public void run() { | |||
|
|
|||
| // Check for timed out remote workers. | |||
| recoverFailedCompactions(true); | |||
| handle.releaseLocks(startedAt); | |||
There was a problem hiding this comment.
Releasing the locks will not happen if any code runs into a exception before this line, since it is inside try block
|
|
||
| // Wrap the inner parts of the loop in a catch throwable so that any errors in the loop | ||
| // don't doom the entire thread. | ||
| try { | ||
| handle = txnHandler.getMutexAPI().acquireLock(TxnStore.MUTEX_KEY.Initiator.name()); | ||
| try (TxnStore.MutexAPI.LockHandle handle = mutex.acquireLock(TxnStore.MUTEX_KEY.Initiator.name())) { |
There was a problem hiding this comment.
looks like, we have to use AutoCloseable here as well ?
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
What changes were proposed in this pull request?
Resolving the Deadlock when the back db is MySQL
Why are the changes needed?
By default MySQL default isolation level is REPEATABLE-READ,
for updatein this isolation will hold the gap lock, if multiple clients are trying tofor updateand theninsertinto the same gap, it cloud cause the deadlock.Does this PR introduce any user-facing change?
A new
hive.metastore.have.multiple.leaders, if it's false, then the same housekeeping tasks will not leverage the db mutex to block each other.Is the change a dependency upgrade?
No
How was this patch tested?
Testing the PR locally, querying from mysql information_schema.INNODB_TRX table, showing that trx_isolation_level of the new trx is 'READ COMMITTED'