Couldn't hurt to open a feature request for this on the tracker.
--
Jason Dillaman
----- Original Message -----
> From: "Haomai Wang" <haomaiwang@xxxxxxxxx>
> To: "Allen Liao" <aliao.svsgames@xxxxxxxxx>
> Cc: ceph-users@xxxxxxxxxxxxxx
> Sent: Saturday, November 21, 2015 11:57:11 AM
> Subject: Re: librbd - threads grow with each Image object
>
> Hmm, I checked again with librbd codes. Each image will create two
> threads one for finisher, another is SafeTimer. So your case is
> reasonable.
>
> @jason @josh We may reduce this via lookup_or_create_singleton_object too?
>
> On Sat, Nov 21, 2015 at 3:51 PM, Allen Liao <aliao.svsgames@xxxxxxxxx> wrote:
> > I'm on 0.94.5.
> >
> > No, rbd cache is not enabled. Even if each Image creates only one extra
> > thread, if I have tens of thousands of Image objects open, there will be
> > tens of thousands of threads in my process. Practically speaking, am I not
> > allowed to cache Image objects?
> >
> > On Fri, Nov 20, 2015 at 8:24 PM, Haomai Wang <haomaiwang@xxxxxxxxx> wrote:
> >>
> >> What's your ceph version?
> >>
> >> Do you enable rbd cache? By default, each Image should only have one
> >> extra thread(maybe we also should obsolete this?).
> >>
> >> On Sat, Nov 21, 2015 at 9:26 AM, Allen Liao <aliao.svsgames@xxxxxxxxx>
> >> wrote:
> >> > I am developing a python application (using rbd.py) that requires
> >> > querying
> >> > information about tens of thousands of rbd images. I have noticed that
> >> > the
> >> > number of threads in my process grow linearly with each Image object
> >> > that is
> >> > created.
> >> >
> >> > After creating about 800 Image objects (that all share a single ioctx),
> >> > my
> >> > process already has more than 2000 threads. I get the thread count
> >> > using
> >> > `ps huH p <pid> | wc -l`.
> >> >
> >> > If I call close() on each Image object after operating on it then the
> >> > threads are cleaned up. However, I want to cache these objects and
> >> > reuse
> >> > them since it is expensive to create tens of thousands of these objects
> >> > all
> >> > the time.
> >> >
> >> > Is it correct for librbd to create 4-5 threads for each Image object
> >> > created?
> >> >
> >> > For example, I'm doing something similar to:
> >> > -------------
> >> >
> >> > import rbd
> >> > import rados
> >> >
> >> > cluster = rados.Rados(conffile='my_ceph.conf')
> >> > cluster.connect()
> >> > ioctx = cluster.open_ioctx('mypool')
> >> >
> >> > # With each object, new threads are created until close() is called
> >> > image0 = rbd.Image(ioctx, 'myimage0')
> >> > image1 = rbd.Image(ioctx, 'myimage1')
> >> > ...
> >> > image9000 = rbd.Image(ioctx, 'myimage9000')
> >> >
> >> >
> >> > _______________________________________________
> >> > ceph-users mailing list
> >> > ceph-users@xxxxxxxxxxxxxx
> >> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
> >> >
> >>
> >>
> >>
> >> --
> >> Best Regards,
> >>
> >> Wheat
> >
> >
>
>
>
> --
> Best Regards,
>
> Wheat
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