You can use ZMQ_ROUTER_MANDATORY to get an error if a message is unroutable. But in any case it will never block on sending.
On Thu, Jul 25, 2013 at 9:39 PM, Justin Karneges <[email protected]> wrote: > On 07/25/2013 12:28 PM, Yannick Hold-Geoffroy wrote: >> Hello everyone, >> >> I've got two questions about router sockets. >> >> First, it seems I must wait for a while after connecting a router socket >> before sending data to its newly connected destination using pyzmq. >> >> This simple use case <http://pastebin.com/kPK2ZAc5> shows the problem on >> my system using pyzmq 13.0.0 with zeromq 3.2.2 (Arch Linux, kernel >> 3.9.9, GCC 4.8.1): Most of the time it runs correctly and terminates, >> but sometimes it prints up to around 900 and stall there. Note that >> adding a sleep before sending (I tried with ~50ms) always make the code >> works. >> >> The router socket always exhibits its POLLOUT flag even if the >> connection isn't ready to send to a newly connected peer. Is there a way >> to ask the zeromq socket when it's ready to accept messages to a given >> host without dropping them, aside from manually specifying a sleep? >> >> >> My second question is about sending. Still using a router socket, you >> could set as destination anything you'd like (even if the socket isn't >> currently connected to a peer with this identity). Is there a way to >> know if a connection is currently available for sending (ie. the message >> will be sent immediately, like POLLOUT for a given peer)? >> >> I've tried setting the socket's ZMQ_SNDTIMEO to zero and try sending >> using the ZMQ_NOBLOCK to see if it would raise (in pyzmq) an ZMQ_EAGAIN >> error, but it always seems to pass without problem even when there is >> nobody listening. A minimal code exhibiting my comprehension of how it >> should work can be found here <http://pastebin.com/zQE2Awt4>. Is there >> something I haven't understood about how it's supposed to work? > > Hi Yannick, > > The simple answer is that ROUTER has a drop policy, not a blocking one. > And there is not a way to know with pure 0mq whether or not there is a > recipient available. That is something you would need to build on top. > > Justin > > _______________________________________________ > zeromq-dev mailing list > [email protected] > http://lists.zeromq.org/mailman/listinfo/zeromq-dev _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
