[jira] [Resolved] (KUDU-1368) Setting snapshot timestamp to last propagated timestamp should include prior writes

["David Alves (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/KUDU-1368?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

David Alves resolved KUDU-1368.
-------------------------------
       Resolution: Won't Fix
    Fix Version/s: 1.1.0

Setting the snapshot scan's timestamp based on the last observer timestamp + 1 is a hack we came up for tests, to make sure we would get RYW at the same time minimizing the server's chance to block on the scan (because of in-flights or safe time advancement). When the GA consistency work is done, this will no longer be necessary.

KUDU-1679 will make sure that, even for the current snapshot scans with no provided timestamp ("now" scans), the timestamp taken by the server for the read will be higher than the time of the last write (which was not guaranteed before).

KUDU-1704 Will improve on this further by allowing bounded staleness scans, going a bit further than the hack since it will allow to read more recent data.

> Setting snapshot timestamp to last propagated timestamp should include prior writes
> -----------------------------------------------------------------------------------
>
>                 Key: KUDU-1368
>                 URL: https://issues.apache.org/jira/browse/KUDU-1368
>             Project: Kudu
>          Issue Type: Sub-task
>          Components: client
>    Affects Versions: 0.7.0
>            Reporter: Todd Lipcon
>             Fix For: 1.1.0
>
>
> If I do some writes and then use scanner.SetSnapshotRaw(client->GetLastPropagatedTimestamp()), it seems like the snapshot that gets generated does not include the writes I did. I need to add one to get "read your writes", which seems unintuitive.



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