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https://issues.apache.org/jira/browse/KUDU-1345?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jean-Daniel Cryans updated KUDU-1345:
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Fix Version/s: 0.7.1
> HybridClock can run backwards when clocks are far out of sync
> -------------------------------------------------------------
>
> Key: KUDU-1345
> URL: https://issues.apache.org/jira/browse/KUDU-1345
> Project: Kudu
> Issue Type: Bug
> Affects Versions: 0.7.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Priority: Blocker
> Fix For: 0.7.1, 0.8.0
>
>
> Nick Wolf reported an error he hit on his cluster where transactions were
> assigned out-of-order timestamps. After looking at his WALs for a while, I
> realized we have this bug:
> - the clock gets an update from another node a second in the future
> - we generate a lot of timestamps locally, which causes the clock to
> increment its logical portion
> - the logical portion exceeds the number of bits allocated to it (12 bits
> iirc). The way we return timestamps, this is OK -- we simply add the logical
> and physical portions, so it "wraps" into the physical portion, causing it to
> increment forward a few microseconds as we do thousands of writes.
> - however, our _host_ clock eventually reaches a higher value than the last
> physical portion. This causes us to reset our logical clock portion back to
> 1, which may actually rewind it back in time.
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