One thing to note about expiration and bitcask, which unfortunately has been
causing us much consternation is that key expiration is a silent merge
trigger. I guess what happens is if a key expires that somehow causes
riak to want to merge that bitcask. If you have keys constantly expiring
(which most people probably do, as the reason you want expiry as you have
data that you no longer want after 30 or 90 days), this will cause constant
merging. That expiration has anything to do with merging is not documented.
We worked with Basho support and have a patch which we will be trying soon
which should help but mostly by delaying merging (as opposed to only
expiring on merge and not using expiration as a trigger).
But if you are using expiry and bitcask and notice that for some reason
you are constantly merging small bitcasks despite tuning triggers and
file sizes, then you are probably running into this case.
Anyway, just an FYI as I believe others have complained about constant
merging on this list before,
-Anthony
On Thu, Sep 20, 2012 at 03:44:22PM -0600, David Smith wrote:
> Sorry -- there is not currently an event that notifies external
> systems when keys are being expired. The expiration is done at merge
> time, so you could potentially get a very large number of events all
> at once.
>
> D.
>
> On Thu, Sep 20, 2012 at 12:14 PM, Mike Oxford <moxf...@gmail.com> wrote:
> > When a key comes up on expiration, I would like to know about it.
> >
> > Is this supported anywhere in the Bitcask backend (like {expiry_secs,N}), by
> > any chance?
> >
> > Thanks!
> >
> > -mox
> >
> > _______________________________________________
> > riak-users mailing list
> > riak-users@lists.basho.com
> > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
> >
>
>
>
> --
> Dave Smith
> VP, Engineering
> Basho Technologies, Inc.
> diz...@basho.com
>
> _______________________________________________
> riak-users mailing list
> riak-users@lists.basho.com
> http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
--
------------------------------------------------------------------------
Anthony Molinaro <antho...@alumni.caltech.edu>
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