Open Stack

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?

> It
> combines the ideas pioneered by Amazon's SQS product with additional
> semantics to support event broadcasting.
>
> 	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.