[zeromq-dev] Sub problem

Stefan de Konink stefan at konink.de
Fri Dec 14 00:23:19 CET 2012

Hi Pieter,

On 12/14/12 00:20, Pieter Hintjens wrote:
> Are you connecting SUB to PUB via some firewall or proxy, or is this a
> direct connection?

The same (local) iptables as before, just accept/drop, without any
connection tracking what so ever.

> Also, is the publisher silent for long periods of time?

Typically not (messages every second), but in this case the 'original'
publisher had an issue, which lead to a longer silence.

> The reason I ask is that we've seen connections going 'stale'
> sometimes; TCP not reporting an error at the client side but not
> transmitting anything. It's due to some proxy in the middle getting
> confused, presumably.
> If this is happening, consider sending keep-alive messages from PUB to
> SUB, which the SUB can discard (but must subscribe to, in 3.2).

I was considering this, and using zmq_poll to actually timeout and
reconnect. Would you be interested in a tcpdump of a (failed) test?


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