1. Building High Performance
Scalable TCP/IP Servers with
Apache MINA
Originally presented at ApacheCon Europe 2006 in Dublin
Latest slides and code samples at http://people.apache.org/~proyal
Presented by Peter Royal, <proyal@apache.org>
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2. Goals of this presentation
•Introduction to MINA
•Demonstration of what it can do
•Converting blocking-IO code to MINA
•Hopefully inspire you to use it :)
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3. What is MINA
•Multipurpose Infrastructure for Networked Applications
•A framework (the F word!) for building networked clients
and servers based on non-blocking IO
•http://directory.apache.org/subprojects/mina/
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4. Brief history of MINA
•Started out as Netty2 from Trustin Lee
•Joined the Directory Project as the SEDA-based directory
needed an asynchronous I/O layer.
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5. IoHandler
IoFilter
Inbound
IoFilter
Outbound
IoFilter
IoProcessor
IoAcceptor
Network
Architectural overview
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6. IoSession
•Holder of state for a connection (either client-side or
server-side)
•Passed along with every event
•Important Methods
•write
•close
•get/setAttribute
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7. IoHandler
•Akin to a Servlet IoHandler
•Endpoint of a filter chain
IoFilter
•Important Methods
IoFilter
•sessionOpened
IoFilter
•messageReceived
IoProcessor
•sessionClosed
IoAcceptor
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8. IoFilterChain
•Chain of IoFilter's for each IoSession
•Can setup template chains per IoConnector/IoAcceptor
•Dynamic addition/removal
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9. IoFilters
•Akin to a ServletFilter IoHandler
•View/Hack/Slash the event stream
IoFilter
•Important Methods
IoFilter
•sessionOpened
IoFilter
•messageReceived
IoProcessor
•filterWrite
IoAcceptor
•sessionClosed
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10. IoAcceptor
•Server-side entry point. IoHandler
•Accepts incoming connections and fires
IoFilter
events to an IoHandler
•Important Methods IoFilter
•bind IoFilter
IoProcessor
IoAcceptor
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11. IoConnector
•Client-side entry point
•Initiate connections to a remote service, and fires events to
an IoHandler
•Important Methods
•connect
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12. IoProcessor
•Internal component IoHandler
•Handles reading and writing data to an
IoFilter
underlying connection
•Each connection is associated with a IoFilter
single IoProcessor (shared amongst
IoFilter
multiple connections)
IoProcessor
IoAcceptor
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13. Our Sample Application
•Persistent connections from clients
•Serialize java objects across the wire
•Clients connect and are given a unit of work, which in this
case, is just an instruction for how long to wait until getting
their next instruction.
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14. Monitoring Performance
•Thread activity via jconsole
•CPU Activity via Activity Monitor
•(or your favorite tool)
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15. Limitations
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16. Scalability
•JVM limit on number of threads
•The lovely java.lang.OutOfMemoryError: unable to
create new native thread
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17. Lets convert to MINA!
•Server side first
•(Client to come soon)
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18. Re-testing
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19. New Limitations?
•Java Serialization takes up CPU time
•(a profiler would reveal this)
•OS limit of per-process open files
•(consult the documentation for your OS)
•sysctl / ulimit to view/change on unix-like systems
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20. MINA on the client
•Since we will be using MINA's built-in support for building
protocols, the ProtocolCodecFilter
•Any socket client can talk to MINA
•We’re using MINA on both sides for simplicity in our
examples.
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21. Client is just like the server
•IoHandler and IoFilter's
•Can re-use filters on both client and server sides.
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22. Implementing the protocol.
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23. It still works!
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24. Filters that ship today
•Logging
•Compression
•Blacklist
•SSL
•Requires Java 5
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25. Filters we are working on
•Traffic Shaping
•Rate Limiting
•Performance Monitoring
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26. Some things built on MINA
•LDAP - Apache DS <http://directory.apache.org/
subprojects/apacheds/index.html>
•Flash - red5 <http://www.osflash.org/red5>
•HTTP - AsyncWeb <http://asyncweb.safehaus.org/>
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27. Performance Tips
•Set the number of IoProcessor’s to be equal to the number
of CPU cores.
•Benchmark! Users have found both heap and direct
buffers, pooled and not pooled, to be beneficial depending
on their workloads.
•For ultra-low latency with small message sizes on a local
lan, disable Nagle’s algorithm; the TCP_NODELAY flag.
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28. Questions?
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29. Thank You!
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