An introduction to Apache MINA, a toolkit for building scalable clients and servers in Java leveraging NIO.

1. (if you can’t read this, move closer!)
Apache
The high-performance protocol construction toolkit.
Peter Royal <proyal@apache.org>
Originally presented at ApacheCon US 2007 in
Atlanta, GA
Wednesday, November 14, 2007 1

2. Hi, I’m Peter
http://fotap.org/~osi
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3. MINA hacker since
Fall 2005
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4. Radar Networks
http://radarnetworks.com
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5. San Francisco
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6. Apache Member
http://apache.org
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7. What is MINA?
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8. MINA?
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9. Multipurpose
Infrastructure
Networked
Applications
http://mina.apache.org
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10. Built on Java NIO
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11. Non-Blocking
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12. Asynchronous
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13. Event-Driven
(SEDA!)
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14. Multiple Transports
(framework is really agnostic)
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15. TCP
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16. UDP
(being re-written for 2.0)
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17. In-VM
(great for testing)
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18. Apache Portable
Runtime (APR)
(under development, alternate
TCP/UDP implementation)
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19. (and more..)
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20. Smartly Designed
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21. Follows Inversion of
Control Pattern
(plays nicely with PicoContainer, Spring, etc)
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22. Separation of Concerns
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23. Wire
Protocol
Application
Logic
Rather than this...
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24. Wire Application
Protocol Logic
Concerns are Separated
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25. Stable and Production-
Ready
• v1.0 released Fall 2006
• v1.1 released April 2007
• Same API as v1.0 but uses Java 5 Concurrency primitives
• v2.0 this year
• API simplification based on lessons learned
• Performance boosts too!
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26. Many Protocols & Users
(here are a few...)
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27. Apache
Directory
http://directory.apache.org
LDAPv3, NTP, DNS, DHCP and
Kerberos
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28. SubEthaSTMP
http://subethasmtp.tigris.org/
SMTP
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29. Apache
(incubating)
Qpid
http://cwiki.apache.org/qpid/
Advanced Messaging Queuing
Protocol (AMQP)
(from Wall Street!)
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30. Openfire
http://www.jivesoftware.com/
products/openfire/
XMPP
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31. red5
http://www.osflash.org/red5
RTMP
(talk to Flash player)
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32. ...and more!
(maybe you, next time!)
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33. Key Concepts
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34. ByteBuffer
• Core NIO construct
• MINA version that wraps and provides
additional convenience methods
• auto-expanding, string encoding
• MINA gives control...
• allocate from the Heap or Stack
• optional Pooling
• (in v2, will be non-pooled and heap-only, as it provides the best
performance)
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35. Future
• Represents a function call that completes
asynchronously
• Provides blocking functions to retrieve the
result
• MINA allows callbacks to be invoked upon
completion, so invoking thread can “fire and
forget”
• (unlike the Java 5 Future)
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36. 36
IoHandler
Writes
IoFilter
IoFilter
IoFilter
Reads
IoProcessor
IoService
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37. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Two Versions
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38. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
IoAcceptor
“act as server”
single thread for new connections
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39. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
IoConnector
“act as client”
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40. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Connection instance
is an IoSession
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41. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Handles reads and writes
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42. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Instance count scales
with CPU/Load
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43. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Session fixed to an Instance
(under review for v2)
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44. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Chain of IoFilter’s
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45. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Per Connection
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46. 46
IoHandler
Writes
IoFilter
IoFilter
Reusable
IoFilter
Reads
IoProcessor
IoService
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47. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Hot Deployable
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48. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Filter all events
Read / Write / Idle / etc
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49. Writes
IoProcessor
IoHandler
IoService
IoFilter
IoFilter
IoFilter
Reads
Application Logic
Lives Here
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50. Large Library of
IoFilter’s
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51. Protocol Conversion
• Framework to plug in your own codecs to
handle conversion to/from a ByteBuffer
• Existing codecs
• Text-based
• Java Serialization
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52. Blacklist
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53. Logging
(great for debugging!)
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54. SSL / TLS
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55. Compression
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56. Read Throttling
(write throttling is in 2.0)
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57. Thread Models
(a necessary evil)
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58. “single threaded”
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59. One IoProcessor
Thread
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60. Scalability sucks
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61. Add more IoProcessor
Threads
(at least one per CPU core)
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62. Lowest latency
Scales nicely
(connection latency to be addressed in v2)
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63. “multi threaded”
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64. use ExecutorFilter
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65. IoProcessor threads
only do reads & writes
(the intent)
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66. Filters execute on a
different thread.
(filter location is key!)
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67. Work for a session is
serialized
(queued per session)
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68. Work is delegated to an
Executor
(generally a java.util.concurrent.ThreadPoolExecutor)
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69. Size thread pool to
“active” session count
(too much in queue == OOM!
Use the Read Throttle filter)
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70. “recommended
application pattern”
• use ExecutorFilter as first in chain
• unless you need really low latency
• use ProtocolCodecFilter
• convert the wire protocol into a Java representation
• put application logic into an IoHandler
• store state in the IoSession
• minimum of Java 5
• java.util.concurrent rocks!
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71. Example Time!
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72. Everybody loves a Haiku
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73. This is our Haiku validator
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74. Simple Protocol
• Connect
• Send 3 lines of text
• Receive HAIKU! or NOT A HAIKU:
• (plus a little reason why not)
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75. ProtocolCodecFilter +
TextLineCodecFactory
Bytes to Java String’s. For free!
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76. ToHaikuIoFilter
Three String’s to a Haiku
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77. Filter is very testable
(mock objects rock!)
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78. IoHandler is very simple
Validate Haiku, send result
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79. Also very testable
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80. Very easy to hook it all up
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81. Questions?
(I’m here all week!)
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82. Thank You!
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83. http://mina.apache.org
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