java.lang.OutOfMemoryError: unable to create new native thread

	bootstrap = new ServerBootstrap(new NioServerSocketChannelFactory(
				Executors.newCachedThreadPool(),
				Executors.newCachedThreadPool()));

异常

java.lang.OutOfMemoryError: unable to create new native thread
	at java.lang.Thread.start0(Native Method)
	at java.lang.Thread.start(Thread.java:691)
	at java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:949)
	at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1360)
	at org.jboss.netty.handler.execution.MemoryAwareThreadPoolExecutor.doUnorderedExecute(MemoryAwareThreadPoolExecutor.java:455)
	at org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor$ChildExecutor.execute(OrderedMemoryAwareThreadPoolExecutor.java:292)
	at org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor.doExecute(OrderedMemoryAwareThreadPoolExecutor.java:242)
	at org.jboss.netty.handler.execution.MemoryAwareThreadPoolExecutor.execute(MemoryAwareThreadPoolExecutor.java:440)
	at org.jboss.netty.handler.execution.ExecutionHandler.handleUpstream(ExecutionHandler.java:172)
	at org.jboss.netty.handler.codec.frame.FrameDecoder.exceptionCaught(FrameDecoder.java:378)
	at org.jboss.netty.channel.Channels.fireExceptionCaught(Channels.java:533)
	at org.jboss.netty.channel.AbstractChannelSink.exceptionCaught(AbstractChannelSink.java:48)
	at org.jboss.netty.channel.Channels.fireChannelBound(Channels.java:199)
	at org.jboss.netty.channel.socket.nio.NioWorker$RegisterTask.run(NioWorker.java:185)
	at org.jboss.netty.channel.socket.nio.AbstractNioWorker.processRegisterTaskQueue(AbstractNioWorker.java:430)
	at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:329)
	at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:35)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:722)

通过JvisualVm监控，发现线程数达到1000的时候出现异常，于是怀疑是linux系统做了限制。

ulimit -a
max user processes              (-u) 1024

修改成65535后，继续测试，问题解决。表面上是内存溢出，实际上是linux系统限制