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https://issues.apache.org/jira/browse/CASSANDRA-19448?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17833353#comment-17833353
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Tiago L. Alves commented on CASSANDRA-19448:
--------------------------------------------
Thanks [~brandon.williams] and [~maxwellguo] for your feedback. Wrt. the
granularity of the PIT restore, in theory I understand the support to
microsecond level which is supported internally in C*. I understand the patch
goal to align PIT restore with what C* supports internally. What I miss is the
practical knowledge on how a customer can determine at microsecond level
precision if something is being inserted in a cluster. It's just curiosity and
I would be happy to learn about it.
[~maxwellguo] regarding the patch, I've seen the description for RIP:
* Sorry for the dumb question, what does RIP stands for?
* What I meant about detecting automatic the granularity was that we don't
need to separately attempt to parse seconds, milliseconds, and microseconds.
This can be achieved by using `DateTimeFormatter.ofPattern("yyyy:MM:dd
HH:mm:ss[.[SSSSSS][SSS]]")` which works for all. This allows simplifying the
code a lot by removing the need of the `RIPLEVEL` enum.
I would be willing to to pick up where you left in
[https://github.com/apache/cassandra/pull/3215] and try out that simplification
if you agree.
> CommitlogArchiver only has granularity to seconds for restore_point_in_time
> ---------------------------------------------------------------------------
>
> Key: CASSANDRA-19448
> URL: https://issues.apache.org/jira/browse/CASSANDRA-19448
> Project: Cassandra
> Issue Type: Bug
> Components: Local/Commit Log
> Reporter: Jeremy Hanna
> Assignee: Maxwell Guo
> Priority: Normal
> Fix For: 4.0.x, 4.1.x, 5.0.x, 5.x
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> Commitlog archiver allows users to backup commitlog files for the purpose of
> doing point in time restores. The [configuration
> file|https://github.com/apache/cassandra/blob/trunk/conf/commitlog_archiving.properties]
> gives an example of down to the seconds granularity but then asks what
> whether the timestamps are microseconds or milliseconds - defaulting to
> microseconds. Because the [CommitLogArchiver uses a second based date
> format|https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/commitlog/CommitLogArchiver.java#L52],
> if a user specifies to restore at something at a lower granularity like
> milliseconds or microseconds, that means that the it will truncate everything
> after the second and restore to that second. So say you specify a
> restore_point_in_time like this:
> restore_point_in_time=2024:01:18 17:01:01.623392
> it will silently truncate everything after the 01 seconds. So effectively to
> the user, it is missing updates between 01 and 01.623392.
> This appears to be a bug in the intent. We should allow users to specify
> down to the millisecond or even microsecond level. If we allow them to
> specify down to microseconds for the restore point in time, then it may
> internally need to change from a long.
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