policies: treat SERIAL/LOCAL_SERIAL consistency as LWT for routing#887
Open
mykaul wants to merge 1 commit into
Open
policies: treat SERIAL/LOCAL_SERIAL consistency as LWT for routing#887mykaul wants to merge 1 commit into
mykaul wants to merge 1 commit into
Conversation
Statements with SERIAL or LOCAL_SERIAL consistency level are serialized through the Paxos path on the server, but TokenAwarePolicy only checked is_lwt() (from server prepare metadata) when deciding whether to skip replica shuffling. This meant serial-consistency reads could be routed with shuffled replicas instead of the deterministic order needed for optimal Paxos coordination. Now TokenAwarePolicy also checks the statement's consistency level and skips shuffling for SERIAL/LOCAL_SERIAL, matching LWT routing behavior. Fixes: scylladb#886
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Summary
TokenAwarePolicynow skips replica shuffling for statements withSERIALorLOCAL_SERIALconsistency level, treating them as LWT-routing candidatesis_lwt()(from server prepare metadata) was checked, meaning serial-consistency reads got shuffled replicas instead of deterministic Paxos-optimal orderingFixes: #886
Related: scylladb/java-driver#885