Open Stack

Excerpts from Doug Hellmann's message of 2015-03-12 10:04:57 -0700:
> 
> On Thu, Mar 12, 2015, at 12:47 PM, Clint Byrum wrote:
> > Excerpts from Sean Dague's message of 2015-03-11 05:59:10 -0700:
> > > =============================
> > >  Additional Interesting Bits
> > > =============================
> > > 
> > > Rabbit
> > > ------
> > > 
> > > There was a whole session on Rabbit -
> > > https://etherpad.openstack.org/p/PHL-ops-rabbit-queue
> > > 
> > > Rabbit is a top operational concern for most large sites. Almost all
> > > sites have a "restart everything that talks to rabbit" script because
> > > during rabbit ha opperations queues tend to blackhole.
> > > 
> > > All other queue systems OpenStack supports are worse than Rabbit (from
> > > experience in that room).
> > > 
> > > oslo.messaging < 1.6.0 was a significant regression in dependability
> > > from the incubator code. It now seems to be getting better but still a
> > > lot of issues. (L112)
> > > 
> > > Operators *really* want the concept in
> > > https://review.openstack.org/#/c/146047/ landed. (I asked them to
> > > provide such feedback in gerrit).
> > > 
> > 
> > This reminded me that there are other options that need investigation.
> > 
> > A few of us have been looking at what it might take to use something
> > in between RabbitMQ and ZeroMQ for RPC and notifications. Some initial
> > forays into inspecting Gearman (which infra has successfully used for
> > quite some time as the backend of Zuul) look promising. A few notes:
> > 
> > * The Gearman protocol is crazy simple. There are currently 4 known
> > gearman
> >   server implementations: Perl, Java, C, and Python (written and
> >   maintained by our own infra team). http://gearman.org/download/ for
> >   the others, and https://pypi.python.org/pypi/gear for the python one.
> > 
> > * Gearman has no pub/sub capability built in for 1:N comms. However, it
> >   is fairly straight forward to write workers that will rebroadcast
> >   messages to subscribers.
> > 
> > * Gearman's security model is not very rich. Mostly, if you have been
> >   authenticated to the gearman server (only the C server actually even
> >   supports any type of authentication, via SSL client certs), you can
> >   do whatever you want including consuming all the messages in a queue
> >   or filling up a queue with nonsense. This has been raised as a concern
> >   in the past and might warrant extra work to add support to the python
> >   server and/or add ACL support.
> > 
> > Part of our motivation for this is that some of us are going to be
> > deploying a cloud soon and none of us are excited about deploying and
> > supporting RabbitMQ. So we may be proposing specs to add Gearman as a
> > deployment option soon.
> 
> That sounds really intriguing, and I look forward to reading it and
> learning more about gearman.
> 
> Be forewarned that oslo.messaging is pretty badly understaffed right
> now. Most of the original contributors have moved on, either to other
> parts of OpenStack or out of the community entirely. We can use more
> messaging experts to help with reviews and improvements. 
> 

Noted, and subscribed in gertty. :)