THRIFT-812. contrib: Add a demo of using Thrift over ZeroMQ
git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@991260 13f79535-47bb-0310-9956-ffa450edef68
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+This directory contains some glue code to allow Thrift RPCs to be sent over
+ZeroMQ. Included are client and server implementations for Python and C++,
+along with a simple demo interface (with a working client and server for
+each language).
+
+Thrift was designed for stream-based interfaces like TCP, but ZeroMQ is
+message-based, so there is a small impedance mismatch. Most of issues are
+hidden from developers, but one cannot be: oneway methods have to be handled
+differently from normal ones. ZeroMQ requires the messaging pattern to be
+declared at socket creation time, so an application cannot decide on a
+message-by-message basis whether to send a reply. Therefore, this
+implementation makes it the client's responsibility to ensure that ZMQ_REQ
+sockets are used for normal methods and ZMQ_DOWNSTREAM sockets are used for
+oneway methods. In addition, services that expose both types of methods
+have to expose two servers (on two ports), but the TZmqMultiServer makes it
+easy to run the two together in the same thread.
+
+This code was tested with ZeroMQ 2.0.7 and pyzmq afabbb5b9bd3.
+
+To build, simply install Thrift and ZeroMQ, then run "make". If you install
+in a non-standard location, make sure to set THRIFT to the location of the
+Thrift code generator on the make command line and PKG_CONFIG_PATH to a path
+that includes the pkgconfig files for both Thrift and ZeroMQ. The test
+servers take no arguments. Run the test clients with no arguments to
+retrieve the stored value or with an integer argument to increment it by
+that amount.
+
+This code is not quite what I would consider production-ready. It doesn't
+support all of the normal hooks into Thrift, and its performance is
+sub-optimal because it does some unnecessary copying.