The ZeroMQ Reference Manual specifies the ZeroMQ API.
The ZeroMQ FAQ by the community is the first place to look for answers to frequently asked questions and problems.
- ZeroMQ is the Answer by Ian Barber (video is below)
- Implementing Distributed Applications using ZeroMQ by Francesco Crippa
- Overview of ZeroMQ by Pieter Hintjens
- Multithreading Magic by Pieter Hintjens
Here is a list of ZeroMQ's features.
In 2011, CERN (the European Organization for Nuclear Research) compared CORBA, Ice, Thrift, ZeroMQ, YAMI4, RTI, and Qpid (AMQP). Read their analysis and conclusions. (PDF).
In 2012, the Fedora team moved their fedmsg system from AMQP to ZeroMQ, experiencing a 100 times speedup.
In 2015, Auth0 Webtasks moved their real-time log aggregation from Apache Kafka to ZeroMQ to get a faster and more stable design.
While improved stability and reliability was the key motivation for this transition, the added performance and reduced system complexity were a nice side effects. In the few days since we replaced Kafka with ZeroMQ the quality of my sleep has improved substantially. — Tomasz Janczuk, Auth0
Who is Using ZeroMQ?
Since ZeroMQ is free software we don't track who uses it. However, some organizations that we know use it are: AT&T, Cisco, EA, Los Alamos Labs, NASA, Weta Digital, Zynga, Spotify, Samsung Electronics, Microsoft, and CERN.
Courses and Workshops
- Pieter Hintjens gives regular workshops in ZeroMQ.
This shows a filter that collects data from two different remote publishers and sends it to local subscribers:
import zmq import time context = zmq.Context() subscriber = context.socket (zmq.SUB) subscriber.connect ("tcp://192.168.55.112:5556") subscriber.connect ("tcp://192.168.55.201:7721") subscriber.setsockopt (zmq.SUBSCRIBE, "NASDAQ") publisher = context.socket (zmq.PUB) publisher.bind ("ipc://nasdaq-feed") while True: message = subscriber.recv() publisher.send (message)
The best way to get started with ZeroMQ is to work through some hands-on examples - the concepts are not new, but the ease with which you can compose them takes some getting use to.
"0MQ sockets being asynchronous means that the timings of the physical connection setup and teardown, reconnect and effective delivery are transparent to the user and organized by 0MQ itself. Further, messages may be queued in the event that a peer is unavailable to receive them."
"The more time I spend with ZeroMQ, the less I can think of a reason I'd ever have to open up a raw TCP or UDP socket, except in extraordinary circumstances, again."
"ZeroMQ is a messaging library, which allows you to design a complex communication system without much effort."
"What ZeroMQ does is create an API that looks a lot like sockets, and feels the same, but gives you the messaging styles you actually want. By simply specifying the type of socket when you call zmq_socket you can have multicast, request/reply, and many other styles."
This presentation, "ZeroMQ is the Answer", is by Ian Barber at the PHP UK Conference.
FLOSS Weekly's Randal Schwartz and Aaron Newcomb discuss ZeroMQ with Pieter Hintjens:
Backgrounders and Whitepapers
- Pieter Hintjens and Martin Sustrik explain how ZeroMQ solves the challenge of creating large multicore applications in any language. Also in PDF (8 pages).
- Martin Sustrik explains the differences between broker-based and brokerless messaging approaches.
- Pieter Hintjens explains how edge-to-edge reliability is more scalable and robust than broker-based reliability.
- Martin Sustrik explains the internal design of ZeroMQ's first implementation.