[rabbitmq-discuss] last_blocked_by resource

[Matthias Radestock]

On 15/03/14 16:21, Sean Allen wrote:
> Question about connections getting blocked for resource levels.
>
> Simplifying what we have.
>
> I have an exchange "event"
>
> Queue: handle.event is bound the "event" on node 1.
>
> Node 2 of the cluster is over memory water mark.
>
> I have a connection that is connected to Node 3 of the cluster that is
> publishing to the "event" exchange. How is it possible for that
> connection to end up being blocked for resource reasons?

RabbitMQ cannot know where future messages published on a connection 
might get routed to. So, in your example, the connection to Node 3 could 
be used to publish messages which end up getting enqueued in queues on 
Node 2. Which would be bad.

The upshot is that a resource alarm on any node blocks publishing 
connections on all nodes.

Matthias.