Hi,
Depending on how you plan to use the omap - you might also want to avoid a
large number of key/value pairs as well. CephFS got it's directory fragment
size capped due to large omaps being painful to deal with (see:
http://tracker.ceph.com/issues/16164 and
http://tracker.ceph.com/issues/16177).
Cheers,
KJ
On Thu, Mar 9, 2017 at 3:02 PM, Max Yehorov <myeho...@skytap.com> wrote:
> re: python library
>
> you can do some mon calls using this:
>
> ##----------
> from ceph_argparse import json_command as json_command
>
> rados_inst = rados.Rados(....)
> cluster_handle = rados_inst.connect()
>
> cmd = {'prefix': 'pg dump', 'dumpcontents': ['summary', ], 'format':
> 'json'}
> retcode, jsonret, errstr = json_command(cluster_handle, argdict=cmd)
> ##----------
>
>
> MON commands
> https://github.com/ceph/ceph/blob/a68106934c5ed28d0195d6104bce59
> 81aca9aa9d/src/mon/MonCommands.h
>
> On Wed, Mar 8, 2017 at 2:01 PM, Kent Borg <kentb...@borg.org> wrote:
> > I'm slowly working my way through Ceph's features...
> >
> > I recently happened upon object maps. (I had heard of LevelDB being in
> there
> > but never saw how to use it: That's because I have been using Python! And
> > the Python library is missing lots of features! Grrr.)
> >
> > How fast are those omap calls?
> >
> > Which is faster: a single LevelDB query yielding a few bytes vs. a single
> > RADOS object read of that many bytes at a specific offset?
> >
> > How about iterating through a whole set of values vs. reading a RADOS
> object
> > holding the same amount of data?
> >
> > Thanks,
> >
> > -kb, the Kent who is guessing LevelDB will be slower in both cases,
> because
> > he really isn't using the key/value aspect of LevelDB but is still paying
> > for it.
> >
> > _______________________________________________
> > ceph-users mailing list
> > ceph-users@lists.ceph.com
> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> _______________________________________________
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>
--
Kjetil Joergensen <kje...@medallia.com>
SRE, Medallia Inc
Phone: +1 (650) 739-6580
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