Re: [Gluster-devel] AFR between two bricks over 3000 miles

[nathan]

Any update on this? Would love to be able to use gluster between east and 
west coast sites.


> <>
Nathan Stratton
nathan at robotics.net
http://www.robotics.net

On Tue, 4 Mar 2008, Anand Avati wrote:

> 2008/3/4, address@hidden <address@hidden>:
> > I tried moving this to server side and that did not help. The 74 ms delay
> > between the sites appears to make gluster unusable, even tho there is 100
> > meg of free capacity. Any plans to background some of the back and forth
> > communication so that if you use write-behind you can get close to local
> > speed on writes?
>
>
> currently write-behind works for only write() calls. I too am seeing the
> issue of the highest latency subvolume becoming the bottleneck for
> operations while it is not unfair to expect application performance at the
> fastest subvolume speed. Will discuss with Krishna about the impact and side
> effects and let you know what we come up with.
>
> avati
>
>
>
> > <>
> > Nathan Stratton
> > nathan at robotics.net
> > http://www.robotics.net
> >
> >
> > On Mon, 3 Mar 2008, address@hidden wrote:
> >
> > > On Mon, 3 Mar 2008, Anand Avati wrote:
> > >
> > > > the bottleneck seems to be create/open which is synchronous over all
> > > > subvolumes. do you have numbers without involving the remote site/afr ?
> > >
> > > Just mounted nyc rather then mirror and that cut the time to .076 sec vs
> > > local .01 sec.
> > >
> > > This is a 100 meg link between NYC and SJC and only transferring 748K.
> > My
> > > guess is even if we had a full gig link between the two we would have
> > the
> > > same problem. A message sent from NYC to SJC will still take 60ms to fly
> > > across the country. So if you have a lot of messages flying back and
> > forth
> > > waiting for data to be written you will have this problem.
> > >
> > > Another clue is that it takes 27 sec just to rm -fr the files! If I
> > moved afr
> > > from the client to the server would that help?
> > >
> > > address@hidden glusterfs]# time cp -r /etc/sysconfig/ /share/mirror
> > >
> > > real    0m0.076s
> > > user    0m0.000s
> > > sys     0m0.007s
> > > address@hidden glusterfs]# time cp -r /etc/sysconfig/ /share/
> > >
> > > real    0m0.010s
> > > user    0m0.001s
> > > sys     0m0.006s
> > > address@hidden glusterfs]#
> > >
> > > With mirror mounted (sjc and nyc up):
> > >
> > > address@hidden glusterfs]# time cp -r /etc/sysconfig/ /share/mirror
> > >
> > > real    0m52.195s
> > > user    0m0.000s
> > > sys     0m0.001s
> > >
> > > address@hidden glusterfs]# time rm -fr /share/mirror/*
> > >
> > > real    0m27.030s
> > > user    0m0.000s
> > > sys     0m0.002s
> > >
> > > > <>
> > > Nathan Stratton
> > > nathan at robotics.net
> > > http://www.robotics.net
>
>
>
> --
> If I traveled to the end of the rainbow
> As Dame Fortune did intend,
> Murphy would be there to tell me
> The pot's at the other end.