cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Binh Nguyen <binhn...@gmail.com>
Subject Re: Strange delay in query
Date Mon, 12 Nov 2012 17:31:27 GMT
I don't think that statement is accurate. The minor compaction is still
triggered for small sstables but for the big sstables it may or may not.
By default Cassandra will wait until it finds 4 sstables of the same size
to trigger the compaction so if the sstables are big then it may take a
while to be compacted.
If you are sure that you have a lot of tombstones and they will be deleted
then I think you are safe to go.

-Binh

On Sun, Nov 11, 2012 at 1:51 AM, André Cruz <andre.cruz@co.sapo.pt> wrote:

> On Nov 11, 2012, at 12:01 AM, Binh Nguyen <binhnv80@gmail.com> wrote:
>
> FYI: Repair does not remove tombstones. To remove tombstones you need to
> run compaction.
> If you have a lot of data then make sure you run compaction on all nodes
> before running repair. We had a big trouble with our system regarding
> tombstone and it took us long time to figure out the reason. It turned out
> that repair process also transfers TTLed data (compaction is not triggered
> yet) to the other nodes even that data was removed from the other nodes in
> the compaction phase before that.
>
>
> Aren't compactions triggered automatically? At least minor compactions.
> Also, I read this in
> http://www.datastax.com/docs/1.1/operations/tuning#tuning-compaction :
>
> " After running a major compaction, automatic minor compactions are no
> longer triggered, frequently requiring you to manually run major
> compactions on a routine basis."
> "DataStax does *not* recommend major compaction."
>
> So I'm unsure whether to start triggering manually these compactions… I
> guess I'll have to experiment with it.
>
> Thanks!
>
> André
>

Mime
View raw message