Folien für den Vortrag am 16.12.2010 im Rahmen des Seminars Verteilte Systeme bei Prof. Braun.

1. a practical introduction

6. structure Introduction Why use ? Architecture Hands on! Projects using Future?

7. 1. Introduction

8. What is ? is a high-performance asynchronous messaging library developed by the “iMatix Corporation“ and an open sourcecommunity it 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 effort it is not a complete messaging system no out of the box product  like unwrap it, configure it, start it up it 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, 2010 he left AMQP working group and now supports AMQP 1.0 with the new project ZeroMQ now the latest version is 2.0.10 1. Introduction

11. queue based messaging entity 1 entity 2 queue 1. 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. Scalability one ZeroMQ socket can connect to multiple endpoints it automatically provides load balancing Simplicity the API looks simple compared with raw sockets it is really simple to deliver messages no buffer management is needed Performance no overhead of an over-engineered protocol 2. Why use ?

15. languagebindings Ada Basic C C++ C# (.NET & Mono) Common Lisp D Erlang Go Haskell 2. Why use ?

16. languagebindings node.js Objective-C Perl PHP Python Racket Ruby Ruby Tcl Lua 2. Why use ?

17. 3. Architecture

18. 3. Architecture

19. general architecture application zmq.cpp/zmq.h ctx.cpp tcp_connecter.cpp tcp_socket.cpp Socket_base.cpp

20. 3. Architecture concurrency model ØMQ's concurrency model may a bit confusing at first ØMQ is a multithreaded application without mutexes condition variables semaphores instead, each object will live in its own thread other threads never touch them

21. 3. Architecture concurrency model threads communicate with the aid of messages they called 'commands' to distinguish from user-level ØMQ-messages same way the objects can speak to other objects

22. 3. Architecture threading model Application ZeroMQ I/O Threads Application Thread

23. 3. Architecture threading model Application ZeroMQ I/O Threads Application Thread created outside of ØMQ to access the API created inside of ØMQ to send messages

24. 3. Architecture mailboxsystem threads are only objects with a 'mailbox‘ basically mailboxes are queues to store commands threads retrieve commands from the mailbox mailbox.cpp

25. 3. Architecture API from zmq.cpp

26. 3. Architecture zmq.cpp

27. 3. Architecture zmq.cpp

28. 3. Architecture 3 steps to set up ZeroMQ choose a transport mechanism set up the infrastructure select a messaging pattern

29. 3. Architecture choose a transport mechanism

30. 3. Architecture possible ways to deliver a message: INPROC: an In-Process communication model IPC: an Inter-Process communication model MULTICAST: multicast via PGM, possibly encapsulated in UDP TCP: a network based transport

31. 3. Architecture PGM (Pragmatic General Multicast) is a reliablemulticasttransportprotocol provides a reliable sequence of packets to multiple recipients simultaneously making it suitable for applications like multi-receive

32. 3. Architecture set up the infrastructure

33. 3. Architecture possible infrastructures QUEUE: a forwarder for the request/response messaging pattern FORWARDER: a forwarder for the publish/subscribe messaging pattern STREAMER: a forwarder for the pipelined messaging pattern

34. 3. Architecture select a messaging pattern

35. 3. Architecture REQUEST/REPLY: bidirectional, load balanced and state based PUBLISH/SUBSCRIBE: publish to multiple recipients at once UPSTREAM / DOWNSTREAM: distribute data to nodes arranged in a pipeline PAIR: communication exclusively between peers old pattern  only for specific applications

36. 3. Architecture valid socket combinations PUB and SUB REQ and REP REQ and XREP XREQ and REP XREQ and XREP XREQ and XREQ XREP and XREP PUSH and PULL PAIR and PAIR zmq.h

37. 3. Architecture REQUEST/REPLY:

38. 3. Architecture PUBLISH/SUBSCRIBE:

39. 3. Architecture UPSTREAM / DOWNSTREAM:

40. 4. Hands on!

41. 4. Hands on! basic concepts hwserver.cpp

42. 4. Hands on! basic concepts hwserver.py

43. 4. Hands on! basic concepts hwserver.cpp

44. 4. Hands on! ctx.cpp

45. 4. Hands on! ctx.cpp

46. 4. Hands on! basic concepts ctx.h

47. 4. Hands on! basic concepts ctx.h

48. 4. Hands on! basic concepts zmq.cpp

49. 4. Hands on! basic concepts hwserver.cpp

50. 4. Hands on! basic concepts zmq.cpp

51. 4. Hands on! Socket_base.cpp

52. 4. Hands on! Socket_base.cpp

53. config.hpp 4. 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 system additional language bindings only available as source package

56. 5. Projects using ZeroMQ

57. 5. Projects using ZeroMQ Projects using ZeroMQ Dripdrop (JavascriptReactorpattern) Zeromqt (Qt) Soaplib (Python) C++ wrapper of zmq::poll zdevicesdevicesproject JeffMQ (peertopeerqueueframework) 0MQ pluginforRabbitMQ TCP thinstreams ZMQMachine (Ruby) (reactorpattern)

58. 6. Future?

59. Future? ØMQ 3.0 Roadmap TCP virtual services / virtual endpoints Pattern Checking API Simplifikation Removals

60. Future? ØMQ 3.0 Roadmap context configuration it is not possible to dynamically configure a context at this time

61. thanks for your attention!