[zeromq-dev] Understanding ØMQ PubSub Scaling

[Pieter Hintjens]

On Tue, Jan 11, 2011 at 10:37 PM, Martin Sustrik <sustrik at 250bpm.com> wrote:

>> Is it
>> copying the data round 10k times, or is it doing something sneakier?
>
> It's not copying data, but with small messages it's unlikely to make
> much difference.

If you use unicast - tcp, inproc, ipc - the data gets sent
individually to each subscriber.  The proper transport for large
numbers of subscribers is multicast, thus pgm.

-Pieter