[zeromq-dev] ROUTER and blocking

[Pieter Hintjens]

On Sat, Sep 22, 2012 at 2:23 AM, Justin Karneges <justin at affinix.com> wrote:

> When does a write to ROUTER block? Is it if the identified connection has a
> full queue?

ROUTER sockets *drop* messages when the HWM is reached.

> Also, if the identified connection does not exist, I assume the socket drops
> the message rather than blocking until that connection appears?

Also, yes.

In fact dropping messages that can't be sent safely is a sane
response. But not by itself. You have to add some form of credit based
flow control, which can be fairly simple.

There's an older article on this here: http://unprotocols.org/blog:15

I've also been working on Chapter 6 of the Guide which goes into
detail on this: http://zguide.zeromq.org/page:all#toc129

-Pieter