[openstack-dev] [Zaqar] Call for adoption (or exclusion?)

Ryan Brown rybrown at redhat.com
Mon Apr 20 18:38:57 UTC 2015

On 04/20/2015 02:22 PM, Michael Krotscheck wrote:
> What's the difference between openstack/zaqar and stackforge/cue?
> Looking at the projects, it seems like zaqar is a ground-up
> implementation of a queueing system, while cue is a provisioning api for
> queuing systems that could include zaqar, but could also include rabbit,
> zmq, etc...
> If my understanding of the projects is correct, the latter is far more
> versatile, and more in line with similar openstack approaches like
> trove. Is there a use case nuance I'm not aware of that warrants
> duplicating efforts? Because if not, one of the two should be retired
> and development focused on the other.
> Note: I do not have a horse in this race. I just feel it's strange that
> we're building a thing that can be provisioned by the other thing.

Well, with Trove you can provision databases, but the MagnetoDB project
still provides functionality that trove won't.

The Trove : MagnetoDB and Cue : Zaqar comparison fits well.

Trove provisions one instance of X (some database) per tenant, where
MagnetoDB is one "instance" (collection of hosts to do database things)
that serves many tenants.

Cue's goal is "I have a not-very-multitenant message bus (rabbit, or
whatever)" and makes that multitenant by provisioning one per tenant,
while Zaqar has a single install (of as many machines as needed) to
support messaging for all cloud tenants. This enables great stuff like
cross-tenant messaging, better physical resource utilization in
sparse-tenant cases, etc.

As someone who wants to adopt Zaqar, I'd really like to see it continue
as a project because it provides things other message broker approaches

Ryan Brown / Software Engineer, Openstack / Red Hat, Inc.

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