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From Anurag Gujral <>
Subject Re: strange behaviour in cassandra
Date Sun, 08 May 2011 18:59:10 GMT
Thanks for your response I think the reference you are talking about is

On Sun, May 8, 2011 at 11:01 AM, Peter Schuller <
> wrote:

> >           I stop my cassandra node and restarted it,this start and stop
> > resulted in decrease in the space used by cassandra by 20%.
> > I am not sure what is happening?Can Anyone please shower some light on
> this
> Probably because unused sstables were deleted on start-up that were
> otherwise not used, and waiting on full GC to be removed. Check
> system.log for "deleted sstable" messages. I didn't find a wiki ref
> right now, but in short cassandra uses weak references to discover
> when an sstable is guaranteed to no longer be used, in order to
> perform removals of the actual sstable files. This can lead to a delay
> of sstable removal which will vary with whatever else is happening
> (the more busy the node, the more often a concurrent mark/sweep gc
> phase is triggered, and the more frequently obsolete sstables are
> deleted).
> --
> / Peter Schuller

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