Allow LogMergePolicy to merge more than mergeFactor segments together when the merge is below the min merge size.
#14166
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
…ther when the merge is below the min merge size. This is essentially porting apache#266 to `LogMergePolicy`. By allowing more than `mergeFactor` segments to be merged together for small merges, the merge policy gets a lower write amplification and indexes have fewer small segments.
|
@original-brownbear I remember you looked at indexes that had more segments (and more small segments in particular) than you would have liked, so you may be interested in this. |
original-brownbear
approved these changes
Jan 24, 2025
There was a problem hiding this comment.
I don't have massive experience with the performance impact of merging more segments but seeing how all of this involves tiny segments only anyway + code looks good => LGTM, thanks! Looking at the problematic segments I've observed here and there, this seems like it should prevent a good chunk of those :)
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Outdated suggestions cannot be applied.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.
This is essentially porting #266 to
LogMergePolicy. By allowing more thanmergeFactorsegments to be merged together for small merges, the merge policy gets a lower write amplification and indexes have fewer small segments.