Open Stack

On 09/10/2014 03:18 PM, Gordon Sim wrote:
> On 09/10/2014 09:58 AM, Flavio Percoco wrote:
>> To clarify the doubts of what Zaqar is or it's not, let me quote what's
>> written in the project's overview section[0]:
>>
>>     "Zaqar is a multi-tenant cloud messaging service for web developers.
> 
> How are different tenants isolated from each other? Can different
> tenants access the same queue? If so, what does Zaqar do to prevent one
> tenant from negatively affecting the other? If not, how is communication
> with other tenants achieved.
> 
> Most messaging systems allow authorisation to be used to restrict what a
> particular user can access and quotas to restrict their resource
> consumption. What does Zaqar do differently?

Zaqar keeps queues/groups isolated in a per-tenant basis. As of now,
there's still no way to make 2 tenants access the same group of
messages. However, we've already discussed - we'll likely work on that
during Kilo - a way to provide a more fine-grained access control on
messages.

>>
>>     The service features a fully RESTful API, which developers can use to
>> send messages between various components of their SaaS and mobile
>> applications, by using a variety of communication patterns. Underlying
>> this API is an efficient messaging engine designed with scalability and
>> security in mind.
>>
>>     Other OpenStack components can integrate with Zaqar to surface events
>> to end users and to communicate with guest agents that run in the
>> "over-cloud" layer.
> 
> I may be misunderstanding the last sentence, but I think *direct*
> integration of other OpenStack services with Zaqar would be a bad idea.
> 
> Wouldn't this be better done through olso.messaging's notifications in
> some way? and/or through some standard protocol (and there's more than
> one to choose from)?
> 
> Communicating through a specific, fixed messaging system, with its own
> unique protocol is actually a step backwards in my opinion, especially
> for things that you want to keep as loosely coupled as possible. This is
> exactly why various standard protocols emerged.
> 

Yes and no. The answer is yes most of the time but there are use cases,
like the ones mentioned here[0], that make zaqar a good tool for the job.

[0] https://etherpad.openstack.org/p/zaqar-integrated-projects-use-cases

-- 
@flaper87
Flavio Percoco