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From Mikhail Panchenko...@mihasya.com>
Subject Re: Assertions running Cleanup on a 3-node cluster with Cassandra 1.1.4 and LCS
Date Tue, 11 Sep 2012 21:59:35 GMT
Based on the steps outlined here
https://issues.apache.org/jira/browse/CASSANDRA-4644?focusedCommentId=13453156&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13453156it
seems that LCS was not used until after 1.1.4 and they were able to do
a
full repair cleanup compact cycle on 1.1.4 before running into problems.

I don't see any major bugfixes for LCS in 1.1.5 either, so this appears to
be a legitimate bug if the timeline is correct.

On Tue, Sep 11, 2012 at 2:50 PM, Omid Aladini <omidaladini@gmail.com> wrote:

> On Tue, Sep 11, 2012 at 8:33 PM, Janne Jalkanen
> <janne.jalkanen@ecyrd.com> wrote:
> >
> >> A bug in Cassandra 1.1.2 and earlier could cause out-of-order sstables
> >> and inter-level overlaps in CFs with Leveled Compaction. Your sstables
> >> generated with 1.1.3 and later should not have this issue [1] [2].
> >
> > Does this mean that LCS on 1.0.x should be considered unsafe to
> > use? I'm using them for semi-wide frequently-updated CounterColumns
> > and they're performing much better on LCS than on STCS.
>
> That's true. "Unsafe" in the sense that your data might not be in the
> right shape with respect to order of keys in sstables and LCS's
> properties and you might need to offline-scrub when you upgrade to the
> latest 1.1.x.
>
> >> In case you have old Leveled-compacted sstables (generated with 1.1.2
> >> or earlier. including 1.0.x) you need to run offline scrub using
> >> Cassandra 1.1.4 or later via /bin/sstablescrub command so it'll fix
> >> out-of-order sstables and inter-level overlaps caused by previous
> >> versions of LCS. You need to take nodes down in order to run offline
> >> scrub.
> >
> > The  1.1.5 README does not mention this. Should it?
>
> The fix was released on 1.1.3 (LCS fix) and 1.1.4 (offline scrub) and
> I agree it would be helpful to have it on NEWS.txt.
>
> Cheers,
> Omid
>
> > /Janne
> >
>

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