EXPERIMENTAL: change celery pool support from prefork to threads #1437
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
terrazoon
changed the title
terrazoon
requested review from
ccostino,
xlorepdarkhelm,
stvnrlly and
A-Shumway42
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Outdated suggestions cannot be applied.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.
Description
The article referenced in issue #1432 says that prefork is the default pool support for Celery because it is robust and pythonic and good for CPU bound apps. The problem becomes when you have an IO bound app, and you find out that prefork is a CPU hog. Prefork holds onto CPU utilization even when nothing is going on. Our last load test showed that we seemed to exceed our allocated CPU utilization by a wide margin and this seemed to destabilize the app towards the end of the test.
By switching to threads, we will have more concurrency, less CPU utilization, and less memory utilization. ASSUMING IT IS STABLE. The caveats are that everything has to be thread safe. We are currently using multiprocessing.Manager (thread safe) and ThreadPoolExecutor (thread safe) so we might be good here.
Testing locally this of course works perfectly fine. We should do a load test on production after hours and see if this would be a viable approach.
Security Considerations