[Pharo-users] Re: Communication between different images

[Sven Van Caekenberghe]

> On 30 Jun 2021, at 01:28, Esteban Maringolo <emaring...@gmail.com> wrote:
> 
> I like the Ansible approach using RabbitMQ, in particular because it
> would also work to delegate tasks to workers (even if in the same
> image), and the task queue would be preserved, whilst in MQTT if there
> are no subscribers for a topic, then all messages sent to it are
> discarded.

That is correct but less of a problem in practice than it seems to be at first 
sight.

As a client, you normally have to be able to start from scratch and load 
everything that came before the moment you start up.

When a client with a specific ID has connected once with clean session false, 
QoS 1 and a subscription, the persistence of the queue will be enabled for a as 
long as the server lives (and maybe even beyond restarts).

There is absolutely no question that Rabbit MQ has much more functionality, I 
found Mosquitto MQTT very nice to work with, but as always, YMMV.

Sven