[zeromq-dev] Seldom publisher is not listened to for long ?

[Pieter Hintjens]

2011/5/16 Martin Raspaud <martin.raspaud at smhi.se>:

> I have a very simple pub/sub scheme (1 pub, 1 sub) talking over an IPSec
> tunnel.
>
> This seems to work great when publishing messages regularly. However, a
> typical use case for us would be to publish one message every two or
> three hours. In those cases we have noticed that the subscriber after a
> while is just not receiving any messages anymore (no obvious error
> message or so).
>
> We fixed the problem by implementing a heartbeat, but I'm a bit
> sceptical. ZeroMQ should know better, right ? Or maybe is this not a zmq
> problem, maybe it's related to an underlying network layer ? Does anyone
> have an idea on this ?

It's possible the tunnel itself has a timeout for inactivity, and you
can presumably raise this. Sending a keep-alive heartbeat is an OK
workaround but obviously not as good as understanding what's actually
going on.

-Pieter