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Isaac Reath commented on CASSANDRA-10726: ----------------------------------------- I've had an issue pop up a couple of times where blocking read repair failing caused reads to time out where [https://github.com/apache/cassandra/pull/94] would have solved the issue. I'd be more than happy to write a 3.11 backport of the speculative retry logic if there was any interest in the community in having one. > Read repair inserts should not be blocking > ------------------------------------------ > > Key: CASSANDRA-10726 > URL: https://issues.apache.org/jira/browse/CASSANDRA-10726 > Project: Cassandra > Issue Type: Improvement > Components: Legacy/Coordination > Reporter: Richard Low > Assignee: Blake Eggleston > Priority: Normal > Fix For: 4.0 > > > Today, if there’s a digest mismatch in a foreground read repair, the insert > to update out of date replicas is blocking. This means, if it fails, the read > fails with a timeout. If a node is dropping writes (maybe it is overloaded or > the mutation stage is backed up for some other reason), all reads to a > replica set could fail. Further, replicas dropping writes get more out of > sync so will require more read repair. > The comment on the code for why the writes are blocking is: > {code} > // wait for the repair writes to be acknowledged, to minimize impact on any > replica that's > // behind on writes in case the out-of-sync row is read multiple times in > quick succession > {code} > but the bad side effect is that reads timeout. Either the writes should not > be blocking or we should return success for the read even if the write times > out. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org