Netty NIO 框架性能压测 – 长链接

压测准备

1. 需要将ulimit -n 改大，否则nio链接开不大。
2. 准备4台机器(1台netty服务器，3台压测机)
3. 使用apache的ab做压测工具

开始干活

压测代码：

package org.dueam.sample.netty;
package org.dueam.sample.netty;
 
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.Executors;
 
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.DynamicChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFactory;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelHandler;
import org.jboss.netty.channel.ChannelHandler.Sharable;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
 
public class ChatServer {
 
	public static void main(String[] args) throws Exception {
		if(args.length <1){
			args = new String[]{"9876","true"};
		}
		ChannelFactory factory = new NioServerSocketChannelFactory(Executors
				.newCachedThreadPool(), Executors.newCachedThreadPool());
 
		ServerBootstrap bootstrap = new ServerBootstrap(factory);
 
		ChatServerHandler handler = new ChatServerHandler();
		ChannelPipeline pipeline = bootstrap.getPipeline();
		pipeline.addLast("chat", handler);
 
		bootstrap.setOption("child.tcpNoDelay", true);
		bootstrap.setOption("child.keepAlive", true);
		int port = Integer.valueOf(args[0]);
		bootstrap.bind(new InetSocketAddress(port));
 
		boolean fillChat = "true".equals(args[1]);
		if (fillChat) {
			ChannelManagerThread cmt = new ChannelManagerThread();
			cmt.start();
		}
 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		while (true) {
			String command = br.readLine();
			if ("dump".equals(command)) {
				System.out.println("当前活着的数量:" + channel.size());
			} else if ("help".equals(command)) {
				System.out.println("命令列表:");
				System.out.println("dump:打印当前情况");
				System.out.println("help:帮助文档");
			}
		}
 
	}
	final static Random random = new Random();
	static int max = 0;
	static class ChannelManagerThread extends Thread {
		@Override
		public void run() {
			while (true) {
				try {
					if(max < channel.size()){
						max = channel.size() ;
						System.out.println("live:"+channel.size());
					}
 
					for (Channel s : channel.values()) {
						if (random.nextInt(100)>70) {
						ChannelBuffer cb = new DynamicChannelBuffer(256);
						cb.writeBytes("Hey!有人来找你了!".getBytes());
						s.write(cb);
						}
					}
					sleep(500);
				} catch (InterruptedException e) {
 
				}
			}
		}
	}
 
	final static Map<Integer, Channel> channel = new HashMap<Integer, Channel>();
 
	static void log(String message) {
		System.out.println(message);
	}
 
	@Sharable
	static class ChatServerHandler extends SimpleChannelHandler {
		@Override
		public void channelConnected(ChannelHandlerContext ctx,
				ChannelStateEvent e) {
			Channel ch = e.getChannel();
			ChannelBuffer cb = new DynamicChannelBuffer(256);
			cb.writeBytes("Hell!你来了啊!".getBytes());
			ch.write(cb);
			channel.put(e.getChannel().getId(), e.getChannel());
		}
 
 
		@Override
		public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
		}
 
		@Override
		public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
			e.getCause().printStackTrace();
			channel.remove(e.getChannel().getId());
			log("remove channel by exception! id:" + e.getChannel().getId());
 
			e.getChannel().close();
		}
 
		@Override
		public void channelDisconnected(ChannelHandlerContext ctx,
				ChannelStateEvent e) throws Exception {
			channel.remove(e.getChannel().getId());
			log("remove channel by exception! id:" + e.getChannel().getId());
 
		}
	}
}

压测方式：

#加大超时和并发量，并使用keep-alive的方式保持住端口
./ab -n 20000 -c 20000 -k -t 999999999 -r http://192.168.216.30:9876/

压测结果

内存损耗：

[root@cap216030 ~]# free -k -t -s 10
-- 原始内存
             total       used       free     shared    buffers     cached
Mem:       4149076     189828    3959248          0      13196      95484
-/+ buffers/cache:      81148    4067928
Swap:      2096472        208    2096264
Total:     6245548     190036    6055512
 
-- 执行 chat server之后
             total       used       free     shared    buffers     cached
Mem:       4149076     207236    3941840          0      13216      96244
-/+ buffers/cache:      97776    4051300
Swap:      2096472        208    2096264
Total:     6245548     207444    6038104
 
-- 59471 个nio连接之后
             total       used       free     shared    buffers     cached
Mem:       4149076     474244    3674832          0      13328      96132
-/+ buffers/cache:     364784    3784292
Swap:      2096472        208    2096264
Total:     6245548     474452    5771096

结论：

1. Netty nio 可以轻松将链接开到6W，每个线程大概损坏5k左右的系统内存

后续压测方案

1. 编写Java客户端做内容实时双向推送
2. 使用100台机器每台机器起1000个线程来模拟客户端进行压测

原文转自 http://dueam.org/