About
ngx_zeromq is a transport module which allows nginx to use ZeroMQ
message-oriented transport layer when communicating with upstream servers.
It's level 7 protocol agnostic, which means that it can be used with any
well-behaving upstream modules (proxy, fastcgi, uwsgi, scgi, etc.).
Status
This is experimental module.
Caveats
At this time, ngx_zeromq support only REQ/REP ZeroMQ sockets, which means
that upstream response must be delivered in a single ZeroMQ message (although
it can be multipart message).
Each message part must fit into upstream buffer (as defined by
proxy_buffer_size, proxy_buffers and other directives).
ZeroMQ is hungry for file descriptors, it will crash and bring worker process
down with it once it runs out of them. In order to guarantee that it doesn't
happen, worker connections limit (see: worker_connections) should be set
few times lower than the file descriptors limit (see: worker_rlimit_nofile).
SSL is another transport module, which means that it cannot be combined with
ngx_zeromq on the same connection (but this matters only for communication
with upstream servers, clients can still use SSL when connecting to nginx).
Configuration directives
zeromq_threads
- syntax:
zeromq_threads <number> - default:
1 - context:
main
Configure number of ZeroMQ I/O threads to be used by each worker process.
zeromq_local
- syntax:
zeromq_local <socket_type> <local_endpoint> - default:
none - context:
upstream
Configure local ZeroMQ endpoint (must use random port numbers).
zeromq_remote
- syntax:
zeromq_remote <socket_type> <remote_endpoint> - default:
none - context:
upstream
Configure remote ZeroMQ endpoint (cannot use random port numbers).
zeromq_single
- syntax:
zeromq_single on|off - default:
off - context:
upstream
Enable single mode which allows use of predefined port numbers for local
endpoints. It comes at a price (only one worker can bind to such endpoint
and it will stop working after nginx reload) and it's supposed to be used
only during testing and development. Do not use this mode in production.
Sample configuration
Use HTTP over ZeroMQ (using standard proxy module).
http {
upstream blackhole {
zeromq_remote REQ tcp://127.0.0.1:5555;
}
server {
location / {
proxy_pass http://blackhole;
}
}
}
License
Copyright (c) 2012-2014, FRiCKLE <[email protected]>
Copyright (c) 2012-2014, Piotr Sikora <[email protected]>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.