This document provides an overview of ZeroMQ, including: - What ZeroMQ is and its history as an asynchronous messaging library developed as a simpler alternative to AMQP. - Why use ZeroMQ, highlighting its scalability, simplicity, performance, and language bindings. - ZeroMQ's architecture, including its concurrency model using message passing between threads, infrastructure components like queues and forwarders, and common messaging patterns. - Hands-on examples of basic ZeroMQ concepts like contexts, sockets, and patterns like request/reply and publish-subscribe. - Current and future projects using ZeroMQ, along with the roadmap for Version 3.0 focusing on improvements like TCP services and API simpl

1. a practical introduction

6. structureIntroductionWhy use ?ArchitectureHands on!Projects using Future?

7. 1. Introduction

8. What is ? is a high-performance asynchronous messaging librarydeveloped by the “iMatix Corporation“ and an open sourcecommunityit is a “message queue” system, unlike “message oriented middleware” (no broker architecture)developed as a simple way contrary to AMQP (Advanced Message Queuing Protocol)LGPL/GPLv3 Software written in C++1. Introduction

9. 1. Introduction :it allows designing complex communication systems without much effortit is not a complete messaging system no out of the box product like unwrap it, configure it, start it upit is a higher level socket interface to build up your own messaging system

10. History the original designer of AMQP (Pieter Hintjens, CEO from iMatrix) started ZeroMQ on March 30, 2010he left AMQP working group and now supports AMQP 1.0 with the new project ZeroMQnow the latest version is 2.0.10 1. Introduction

11. queue based messagingentity 1entity 2queue1. Introduction

12. 2.Why use ?

13. 2. Why use ? “If you've done any work with threads, protocols, or networks, you'll realize this is pretty much impossible. It's a dream. Even connecting a few programs across a few sockets is plain nasty, when you start to handle real life situations.”

14. Scalabilityone ZeroMQ socket can connect to multiple endpoints it automatically provides load balancingSimplicitythe API looks simplecompared with raw sockets it is really simple to deliver messagesno buffer management is neededPerformanceno overhead of an over-engineered protocol2. Why use ?

15. languagebindingsAdaBasicCC++C# (.NET & Mono) Common LispDErlangGoHaskell2. Why use ?

16. languagebindingsnode.jsObjective-C PerlPHPPythonRacketRubyRuby TclLua2. Why use ?

17. 3. Architecture

18. 3. Architecture

19. general architectureapplicationzmq.cpp/zmq.hctx.cpptcp_connecter.cpptcp_socket.cppSocket_base.cpp

20. 3. Architecture concurrency modelØMQ's concurrency model may a bit confusing at firstØMQ is a multithreaded application without mutexescondition variablessemaphoresinstead, each object will live in its own threadother threads never touch them

21. 3. Architecture concurrency modelthreads communicate with the aid of messagesthey called 'commands' to distinguish from user-level ØMQ-messagessame way the objects can speak to other objects

22. 3. Architecturethreading modelApplicationZeroMQI/O ThreadsApplication Thread

23. 3. Architecturethreading modelApplicationZeroMQI/O ThreadsApplication Threadcreated outside of ØMQ to access the APIcreated inside of ØMQ to send messages

24. 3. Architecturemailboxsystemthreads are only objects with a 'mailbox‘basically mailboxes are queues to store commandsthreads retrieve commands from the mailboxmailbox.cpp

25. 3. ArchitectureAPI from zmq.cpp

26. 3. Architecturezmq.cpp

27. 3. Architecturezmq.cpp

28. 3. Architecture3 steps to set up ZeroMQ choose a transport mechanismset up the infrastructureselect a messaging pattern

29. 3. Architecturechoose a transport mechanism

30. 3. Architecturepossible ways to deliver a message: INPROC:an In-Process communication modelIPC:an Inter-Process communication modelMULTICAST:multicast via PGM, possibly encapsulated in UDPTCP:a network based transport

31. 3. ArchitecturePGM (Pragmatic General Multicast)is a reliablemulticasttransportprotocolprovides a reliable sequence of packets to multiple recipients simultaneouslymaking it suitable for applications like multi-receive

32. 3. Architectureset up the infrastructure

33. 3. Architecturepossible infrastructures QUEUE:a forwarder for the request/response messaging patternFORWARDER:a forwarder for the publish/subscribe messaging patternSTREAMER:a forwarder for the pipelined messaging pattern

34. 3. Architectureselect a messaging pattern

35. 3. ArchitectureREQUEST/REPLY:bidirectional, load balanced and state basedPUBLISH/SUBSCRIBE:publish to multiple recipients at onceUPSTREAM / DOWNSTREAM:distribute data to nodes arranged in a pipelinePAIR:communication exclusively between peersold pattern  only for specific applications

36. 3. Architecturevalid socket combinationsPUB and SUBREQ and REPREQ and XREPXREQ and REPXREQ and XREPXREQ and XREQXREP and XREPPUSH and PULLPAIR and PAIRzmq.h

37. 3. ArchitectureREQUEST/REPLY:

38. 3. ArchitecturePUBLISH/SUBSCRIBE:

39. 3. ArchitectureUPSTREAM / DOWNSTREAM:

40. 4. Hands on!

41. 4. Hands on!basic conceptshwserver.cpp

42. 4. Hands on!basic conceptshwserver.py

43. 4. Hands on!basic conceptshwserver.cpp

44. 4. Hands on!ctx.cpp

45. 4. Hands on!ctx.cpp

46. 4. Hands on!basic conceptsctx.h

47. 4. Hands on!basic conceptsctx.h

48. 4. Hands on!basic conceptszmq.cpp

49. 4. Hands on!basic conceptshwserver.cpp

50. 4. Hands on!basic conceptszmq.cpp

51. 4. Hands on!Socket_base.cpp

52. 4. Hands on!Socket_base.cpp

53. config.hpp4. Hands on!

54. 4. Hands on!example!!

55. 4. Hands on!get : (only source code version)download source code (git://github.com/zeromq/zeromq2.git)build libraries (Windows MSVS or your favorite Compiler on Linux  )install on systemadditional language bindings only available as source package

56. 5. Projects using ZeroMQ

57. 5. Projects using ZeroMQProjects using ZeroMQDripdrop (JavascriptReactorpattern)Zeromqt (Qt)Soaplib (Python)C++ wrapper of zmq::pollzdevicesdevicesprojectJeffMQ (peertopeerqueueframework)0MQ pluginforRabbitMQTCP thinstreamsZMQMachine (Ruby) (reactorpattern)

58. 6. Future?

59. Future?ØMQ 3.0 RoadmapTCP virtual services / virtual endpointsPattern CheckingAPI SimplifikationRemovals

60. Future?ØMQ 3.0 Roadmapcontext configurationit is not possible to dynamically configure a context at this time

61. thanks for your attention!