Sunday August 28, 2011

[Time] NameMessage
[02:05] mikko Plouj-: which language ?
[02:05] mikko it should generate EFSM
[02:06] mikko if you are using REQ/REP sockets
[04:09] Plouj- mikko: C
[04:11] Plouj- I used this as the server code: and this as the client code: and the server only printed lines like "Received: Hello"
[04:56] sustrik Plouj-: you mean the peer have ignored the malformed message, right?
[04:56] sustrik yes, that's how 0mq handles network errors
[04:57] sustrik ignore and retry
[19:58] zvi hi, what's the recommended way to "unsubscribe"/disconnect subscriber socket with identity from specific publisher socket?
[20:05] sustrik either zmq_setsockopt (ZMQ_UNSUBSCRIBE) or zmq_clos()
[20:05] sustrik zmq_close()
[20:05] mikko does zmq close remove it from publisher side as well?
[20:05] mikko or does the publisher keep buffering?
[20:06] sustrik mikko: you are right, it does not
[20:06] sustrik so unsubscribing seems to be the only option
[20:07] mikko unsubsribing works for 3.0?
[20:07] zvi sustrik, I have a fairly large cluster of nodes, each one with publisher endpoint
[20:08] sustrik it should
[20:11] zvi so I need to send messages in format <<NodeIndex:8 bit, Message >>, then subscribe to each node's publisher using zmq_setsockopt(Subscriber, ZMQ_SUBSCRIBE, <<NodeIndex:8bit>>), then zmq_connect( subscriber, "tcp://node endpoint"). And to disconnect zmq_setsockopt(Subscriber, ZMQ_UNSUBSCRIBE, <<NodeIndex:8bit>>) ?
[20:12] zvi sorry for the pseudocode mizing C and Erlang ;)
[20:12] zvi mixing
[20:13] zvi sustrik, wouldn't zmq_close disconnect from all publishers to which subscriber is connected?
[20:18] zvi Also aren't filters implemented on the receiving side? Therefore If my publisher node is dead unsubscribing from it will give me nothing. I just want to clean things properly, so connections to down nodes will not hang forever.
[20:21] zvi Another question, is Identity should be globally unique or just unique per socket pair?
[20:50] crazed hey is it possible to read the raw data from a zeromq publisher using tcpdump?
[21:01] mikko crazed: yes, of course
[21:12] crazed mikko: do you have an example?
[21:13] mikko crazed: example of what?
[21:14] crazed well actually nvm
[21:14] mikko it's no different from any other tcp stream
[21:14] crazed yeah lol
[21:15] crazed i'm trying to use the collectd zeromq plugin to publish messages, but i can't seem to get any code to subscribe to them
[21:15] crazed though i see traffic on the ports
[21:15] mikko are you actually subscribing to anything on the client code?
[21:15] mikko by default it's subscribed to nothing
[21:16] crazed i'm using python
[21:16] crazed and here's the setsockopt line: socket.setsockopt(zmq.SUBSCRIBE, '')
[21:16] mikko what does the client code look like?
[21:17] crazed
[21:18] crazed if i write my own server that publishes to the same socket, that code reads it without an issue
[21:18] mikko is it actually listening on 6666 ?
[21:23] crazed hm
[21:23] crazed doesn't look like collectd is binding
[21:24] mikko are you sure that collectd doesnt try to connect?
[21:24] mikko change socket.connect to socket.bind in your client code
[21:25] crazed mikko: genius, i didn't even think about that
[21:25] crazed i'm a zmq noob and didn't realize you could do it athat way
[21:26] crazed cool
[23:52] crazed is it typical to have sub do the binding and pub do the connceting, or does it go the other way?
[23:54] crazed hm the guide shows an example where the publisher binds and the subscriber connects