Improve performance and latency with large number of sparse consumers. #3706
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
Jarema
requested changes
Dec 13, 2022
derekcollison
force-pushed
the
sparse-latency
branch
from
32d7458
to
da58841
Compare
When a stream had a large number of consumers on a server that were sparse, the signaling mechanism would do a linear scan to signal matching consumers. As usage patterns have continued to have more consumers that are filteres and sparse, meaning a message is destined for a single or small number of consumers. This change moves selection to a sublist that tracks only active consumer leaders for selection, which optimizes selection of consumers to signal when the number of consumers is large. Signed-off-by: Derek Collison <derek@nats.io>
derekcollison
force-pushed
the
sparse-latency
branch
from
da58841
to
855f790
Compare
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Outdated suggestions cannot be applied.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.
When a stream had a large number of consumers on a server that were sparse, the signaling mechanism would do a linear scan to signal matching consumers. As usage patterns have continued to have more consumers that are filteres and sparse, meaning a message is destined for a single or small number of consumers.
This change moves selection to a sublist that tracks only active consumer leaders for selection, which optimizes selection of consumers to signal when the number of consumers is large.
Signed-off-by: Derek Collison derek@nats.io
/cc @nats-io/core