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https://issues.apache.org/jira/browse/CASSANDRA-9649?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14602629#comment-14602629
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Sylvain Lebresne commented on CASSANDRA-9649:
---------------------------------------------
bq. Is this enough or do we need to revert the entire change introduced by
CASSANDRA-5667?
It is enough. Most of the other change from CASSANDRA-5667 were either not
directly related in the first place, or have been changed since then by other
patches. So I'm good with the current version of you branches and if we're good
with that I'll commit once CI has finished re-running on every branch.
I've moved the discussion about potentially reverting CASSANDRA-7801 to
CASSANDRA-9655 since it's largely orthogonal to this issue (the problem exists
with or without this patch).
> Paxos ballot in StorageProxy could clash
> ----------------------------------------
>
> Key: CASSANDRA-9649
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9649
> Project: Cassandra
> Issue Type: Bug
> Reporter: Stefania
> Assignee: Stefania
> Priority: Minor
>
> This code in {{StorageProxy.beginAndRepairPaxos()}} takes a timestamp in
> microseconds but divides it by 1000 before adding one. So if the summary is
> null, ballotMillis would be the same for up to 1000 possible state timestamp
> values:
> {code}
> long currentTime = (state.getTimestamp() / 1000) + 1;
> long ballotMillis = summary == null
> ? currentTime
> : Math.max(currentTime, 1 +
> UUIDGen.unixTimestamp(summary.mostRecentInProgressCommit.ballot));
> UUID ballot = UUIDGen.getTimeUUID(ballotMillis);
> {code}
> {{state.getTimestamp()}} returns the time in micro seconds and it ensures to
> add one microsecond to any previously used timestamp if the client sends the
> same or an older timestamp.
> Initially I used this code in {{ModificationStatement.casInternal()}},
> introduced by CASSANDRA-9160 to support cas unit tests, but occasionally
> these tests were failing. It was only when I ensured uniqueness of the ballot
> that the tests started to pass reliably.
> I wonder if we could ever have the same issue in StorageProxy?
> cc [~jbellis] and [~slebresne] for CASSANDRA-7801
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