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https://issues.apache.org/jira/browse/KUDU-1869?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15861915#comment-15861915
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David Alves commented on KUDU-1869:
-----------------------------------
Even though the error message could/should be improved (there's a bug where
kudu only fails fast on snapshot scans when hybrid time is disabled if a
snapshot scan timestamp was provided) there's no way that snapshot scans (and
thus ryw) can work correctly without hybridtime being enabled.
Would enabling hybritime in these clusters be a possibility? What about
disabling ryw just in this case?
> Scans do not work with hybrid time disabled and snapshot reads enabled
> ----------------------------------------------------------------------
>
> Key: KUDU-1869
> URL: https://issues.apache.org/jira/browse/KUDU-1869
> Project: Kudu
> Issue Type: Bug
> Components: consensus
> Affects Versions: 1.2.0
> Environment: Centos 6.6
> kudu 1.2.0-cdh5.10.0
> revision 01748528baa06b78e04ce9a799cc60090a821162
> build type RELEASE
> 6 nodes, 5 tservers/impalads
> Reporter: Matthew Jacobs
> Priority: Critical
> Labels: impala
>
> With {{-use_hybrid_clock=false}} and scanning with SNAPSHOT_READ, all scans
> appear to be timing out with the following error message:
> {code}
> [vc0736.halxg.cloudera.com:21000] > SELECT COUNT(*) FROM
> functional_kudu.alltypes;
> Query: select COUNT(*) FROM functional_kudu.alltypes
> Query submitted at: 2017-02-10 09:50:02 (Coordinator:
> http://vc0736.halxg.cloudera.com:25000)
> Query progress can be monitored at:
> http://vc0736.halxg.cloudera.com:25000/query_plan?query_id=ff48eb0af82f057e:f2c1e2f800000000
> WARNINGS:
> Unable to open scanner: Timed out: unable to retry before timeout: Remote
> error: Service unavailable: Timed out: could not wait for desired snapshot
> timestamp to be consistent: Timed out waiting for ts: L: 3632307 to be safe
> (mode: NON-LEADER). Current safe time: L: 3598991 Physical time difference:
> None (Logical clock): Remote error: Service unavailable: Timed out: could not
> wait for desired snapshot timestamp to be consistent: Timed out waiting for
> ts: L: 3625836 to be safe (mode: NON-LEADER). Current safe time: L: 3593993
> Physical time difference: None (Logical clock)
> {code}
> This is a severe issue for Impala which aims to keep SNAPSHOT_READ enabled.
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