From 597cc5edd624525563e6549dc0057eca2a51c81d Mon Sep 17 00:00:00 2001 From: Micah Anderson Date: Tue, 11 Nov 2014 13:30:46 -0500 Subject: upgrade to new version --- doc/zmq_proxy.txt | 98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 doc/zmq_proxy.txt (limited to 'doc/zmq_proxy.txt') diff --git a/doc/zmq_proxy.txt b/doc/zmq_proxy.txt new file mode 100644 index 0000000..cfad779 --- /dev/null +++ b/doc/zmq_proxy.txt @@ -0,0 +1,98 @@ +zmq_proxy(3) +============ + +NAME +---- +zmq_proxy - start built-in 0MQ proxy + + +SYNOPSIS +-------- +*int zmq_proxy (const void '*frontend', const void '*backend', const void '*capture');* + + +DESCRIPTION +----------- +The _zmq_proxy()_ function starts the built-in 0MQ proxy in the current +application thread. + +The proxy connects a frontend socket to a backend socket. Conceptually, data +flows from frontend to backend. Depending on the socket types, replies may flow +in the opposite direction. The direction is conceptual only; the proxy is fully +symmetric and there is no technical difference between frontend and backend. + +Before calling _zmq_proxy()_ you must set any socket options, and connect or +bind both frontend and backend sockets. The two conventional proxy models are: + +_zmq_proxy()_ runs in the current thread and returns only if/when the current +context is closed. + +If the capture socket is not NULL, the proxy shall send all messages, received +on both frontend and backend, to the capture socket. The capture socket should +be a 'ZMQ_PUB', 'ZMQ_DEALER', 'ZMQ_PUSH', or 'ZMQ_PAIR' socket. + +Refer to linkzmq:zmq_socket[3] for a description of the available socket types. + +EXAMPLE USAGE +------------- + +Shared Queue +~~~~~~~~~~~~ + +When the frontend is a ZMQ_ROUTER socket, and the backend is a ZMQ_DEALER +socket, the proxy shall act as a shared queue that collects requests from a +set of clients, and distributes these fairly among a set of services. +Requests shall be fair-queued from frontend connections and distributed evenly +across backend connections. Replies shall automatically return to the client +that made the original request. + +Forwarder +~~~~~~~~~ + +When the frontend is a ZMQ_XSUB socket, and the backend is a ZMQ_XPUB socket, +the proxy shall act as a message forwarder that collects messages from a set +of publishers and forwards these to a set of subscribers. This may be used to +bridge networks transports, e.g. read on tcp:// and forward on pgm://. + +Streamer +~~~~~~~~ + +When the frontend is a ZMQ_PULL socket, and the backend is a ZMQ_PUSH socket, +the proxy shall collect tasks from a set of clients and forwards these to a set +of workers using the pipeline pattern. + +RETURN VALUE +------------ +The _zmq_proxy()_ function always returns `-1` and 'errno' set to *ETERM* (the +0MQ 'context' associated with either of the specified sockets was terminated). + + +EXAMPLE +------- +.Creating a shared queue proxy +---- +// Create frontend and backend sockets +void *frontend = zmq_socket (context, ZMQ_ROUTER); +assert (backend); +void *backend = zmq_socket (context, ZMQ_DEALER); +assert (frontend); +// Bind both sockets to TCP ports +assert (zmq_bind (frontend, "tcp://*:5555") == 0); +assert (zmq_bind (backend, "tcp://*:5556") == 0); +// Start the queue proxy, which runs until ETERM +zmq_proxy (frontend, backend, NULL); +---- + + +SEE ALSO +-------- +linkzmq:zmq_bind[3] +linkzmq:zmq_connect[3] +linkzmq:zmq_socket[3] +linkzmq:zmq[7] + + +AUTHORS +------- +This page was written by the 0MQ community. To make a change please +read the 0MQ Contribution Policy at . -- cgit v1.2.3