Attempt fixing deadlocks by moving account stats update outside transaction #9437
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
ClearlyClaire
force-pushed
the
fixes/fix-deadlocks
branch
2 times, most recently
from
11f06e6
to
b2410fd
Compare
`update_attribute` would normally cause callbacks to be called. Called from a callback, it seems to stop further callbacks from executing. `update_column` does the same work, but without calling callbacks or preventing other callbacks from executing.
ClearlyClaire
force-pushed
the
fixes/fix-deadlocks
branch
from
d5e66b6
to
21105d6
Compare
Gargron
approved these changes
Dec 5, 2018
hiyuki2578
pushed a commit
to ProjectMyosotis/mastodon
that referenced
this pull request
Oct 2, 2019
…action (mastodon#9437) * Use `update_column` instead of `update_attribute` in callback `update_attribute` would normally cause callbacks to be called. Called from a callback, it seems to stop further callbacks from executing. `update_column` does the same work, but without calling callbacks or preventing other callbacks from executing. * Fix deadlocks by moving account stats update outside transaction
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Outdated suggestions cannot be applied.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.
increment_counter_cachesmay cause deadlocks when multiple jobs touch the same account.From my understanding, this is because
Status.createis always called inside a transaction, andincrement_counter_cacheswill be called within that transaction, causing both a read and a write of that particular row within the same transaction.This PR makes the callback executes after the transaction.