Hi all,
I have a server program based on mina which provides services to clients and
also acts as a client of other servers. I found that when there're lots of
client come and request a service and go (at a moment, there aren't so many
clients), the CPU load of my program is very high. I profiled my program
through java's agentlib hprof, like this:
$ java -agentlib:hprof=cpu=samples,depth=8 -cp $MyClassPath MyClass
I got the following results:
......................
TRACE 300291:
sun.nio.ch.PollArrayWrapper.poll0(PollArrayWrapper.java:Unknown
line)
sun.nio.ch.PollArrayWrapper.poll(PollArrayWrapper.java:100)
sun.nio.ch.PollSelectorImpl.doSelect(PollSelectorImpl.java:56)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80)
org.apache.mina.transport.socket.nio.SocketIoProcessor$Worker.run(SocketIoProcessor.java:500)
org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:43)
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
TRACE 300275:
sun.nio.ch.PollArrayWrapper.poll0(PollArrayWrapper.java:Unknown
line)
sun.nio.ch.PollArrayWrapper.poll(PollArrayWrapper.java:100)
sun.nio.ch.PollSelectorImpl.doSelect(PollSelectorImpl.java:56)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:84)
org.apache.mina.transport.socket.nio.SocketAcceptor$Worker.run(SocketAcceptor.java:233)
org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:43)
TRACE 300468:
sun.nio.ch.PollArrayWrapper.poll0(PollArrayWrapper.java:Unknown
line)
sun.nio.ch.PollArrayWrapper.poll(PollArrayWrapper.java:100)
sun.nio.ch.PollSelectorImpl.doSelect(PollSelectorImpl.java:56)
sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:69)
sun.nio.ch.SelectorImpl.select(SelectorImpl.java:80)
org.apache.mina.transport.socket.nio.SocketConnector$Worker.run(SocketConnector.java:389)
org.apache.mina.util.NamePreservingRunnable.run(NamePreservingRunnable.java:43)
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:650)
......................
CPU SAMPLES BEGIN (total = 463435) Thu Jul 26 07:20:34 2007
rank self accum count trace method
1 86.46% 86.46% 400702 300291 sun.nio.ch.PollArrayWrapper.poll0
2 6.14% 92.60% 28460 300275 sun.nio.ch.PollArrayWrapper.poll0
3 4.09% 96.70% 18975 300468 sun.nio.ch.PollArrayWrapper.poll0
......................
It seems that sun.nio.ch.PollArrayWrapper.poll0 takes a lot of CPU time. Is
it normal? If not, what the problem may be?
My main program is like this:
......................
ByteBuffer.setUseDirectBuffers(false);
ByteBuffer.setAllocator(new SimpleByteBufferAllocator());
Executor executor = Executors.newCachedThreadPool();
SocketAcceptor acceptor = new
SocketAcceptor(Runtime.getRuntime().availableProcessors(), executor);
SocketAcceptorConfig config = new SocketAcceptorConfig();
config.setThreadModel(ThreadModel.MANUAL);
config.setReuseAddress(true);
config.getFilterChain().addLast("codec", new ProtocolCodecFilter(new
MyCodecFactory()));
config.getFilterChain().addLast("threadpool", new
ExecutorFilter(executor));
acceptor.bind(new InetSocketAddress(port), handler, config);
......................
Any suggestions will be appreciated! Thanks!
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