[zeromq-dev] Knowing when a client is full

[Martin Sustrik]

On 09/23/2011 09:24 AM, Andrew Davey wrote:

> Our concern is what happens when one of our Clients is unable to
> receive their messages. We can't decide if the documentation is saying
> that ZMQ_ROUTER sockets only drop when the HWM is reached for all
> peers or if messages are dropped if just one peer/Client has reached
> the HWM. Could someone clarify?

It's per peer. Each underlying connection has its own buffer and its own 
HWM.

> Secondly, is there a better way to achieve our goals? Ideally we would
> like a Worker to be able to determine if a Client has reached a HWM
> and then register a callback to be called once things are good again.
> Failing callbacks, the ability to poll a Client that it's good would
> be great.

This can't be done with existing ROUTER socket unfortunately. There's a 
new design of ROUTER socket in the development trunk that would allow 
for that kind of thing but it would have to be backported to the stable 
versions of 0MQ.

Martin