Hello, My name is David W, I am a professional code monkey that was first introduced to 0MQ via Zed Shaw's talk at PyCon ( believe it was 2010 ) but only now have gotten the chance to sit down and start learning the library. I am on a sabbatical until ideal after PyCon since I got laid off and taking the time out to hit a bucket list ( including learning 0MQ ).
On that note, a few years back as a re-invent the wheel project to learn Twisted and COMET I started writing a web MUD engine and centered the architecture around two message pipelines: User action's were locked stepped ( User A moved left, tell server, wait for it to say yes/no), broadcast to other User's that User A moved left, broadcast to all of User A's group they moved left. NPC's were just headless User's driven by a behavior time/tick subprocess that hooked upto the same pipelines. I set that project aside because I realized I needed a message queue of some sort and really didn't want to setup Rabbit or anything super industrial. Now along arrives 0MQ and since this is a personal project the priority is more about understanding how 0MQ works then accomplishing the actual project. In the above example I can imagine using 0mq's inproc socket's where client's are SUB types ( subscribe to map/domain, subscribe to group chat ) and their is a master process that has a router socket for incoming work and a pub socket for products [ User A in map 1 moved left] ). So here's my questions: For PUB/SUB the impression is that the actual queue sit's on the client socket. PUB pushes a message to all client's [ regardless of setsockopt(zmq.SUBSCRIBE ) ] and the act of reading the socket filter's/clears the queue down to what the client is subscribed to. Is this correct or is the subscription more intelligent ( PUB keep's a subscription roster, see's no one is subscribed, drop's the message OR client receives a message, isn't subscribed so it drops the message ). Has anyone had any experience running multiple SUB based client's inside of one process and are their any severe consequences. I imagine a SUB socket is going to instantiate the needed structures to hold a queue, the actual socket, and other house keeping structures but so far small tests (1-10 sockets) hasn't show much memory use. Additionally, if I do get past digging through 0MQ's mechanics, I was thinking it would be best to spin off the PUB side to it's only process. Which leads me to wonder if 0MQ inproc PUB/SUB actually relies on some clever memory mapping. eg Push a message on an inproc PUB socket which goes to a shared/mutex locked list and client's just read from this one list. Apologies if some of these questions seem naive, I haven't gotten the chance to read 0mq's C source code yet. Thanks, Dave _______________________________________________ zeromq-dev mailing list [email protected] http://lists.zeromq.org/mailman/listinfo/zeromq-dev
