我想创建一个聊天服务器来处理不同房间的 100-500 个用户。
我决定使用 Netty 框架,因为基于事件的架构(这对我来说非常熟悉)。我从小型服务器开始,它对收到的所有内容都响应“NYA”。主要的:
public class ChatServer{
public static void main(String[] args) throws Exception {
ExecutorService bossExec = new OrderedMemoryAwareThreadPoolExecutor(1, 400000000, 2000000000, 60, TimeUnit.SECONDS);
ExecutorService ioExec = new OrderedMemoryAwareThreadPoolExecutor(4 /* число рабочих потоков */, 400000000, 2000000000, 60, TimeUnit.SECONDS);
ChannelFactory factory = new NioServerSocketChannelFactory(bossExec,ioExec);
ServerBootstrap bootstrap = new ServerBootstrap(factory);
bootstrap.setPipelineFactory(new ChannelPipelineFactory(){
public ChannelPipeline getPipeline(){
return Channels.pipeline(new ChatChannelHandler());
}
});
bootstrap.setOption("child.tcpNoDelay", true);
bootstrap.setOption("child.keepAlive", true);
bootstrap.setOption("reuseAddress", true);
bootstrap.bind(new InetSocketAddress(5555));
System.out.println("ChatServer started at last...");
}
}
处理程序:
public class ChatChannelHandler extends SimpleChannelUpstreamHandler {
private final ChannelBuffer messageBuffer = ChannelBuffers.dynamicBuffer();
private boolean processingMessage = false;
private short messageLength;
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
System.out.println("Connection from: " + e.getChannel().getRemoteAddress().toString());
}
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
e.getChannel().write(ChannelBuffers.copiedBuffer("NYA!", "UTF-8");
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
System.out.println("Exception: " + e.getCause());
Channel ch = e.getChannel();
ch.close();
}
}
我使用模拟程序创建 N 个连接,然后随机将内容写入服务器,暂停 1-5 秒。然后我连接我的基于 Flash 的客户端,看看它是如何工作的。所以问题是,在 10-90 个连接下,我的 flash 客户端立即从服务器获得响应,但是当模拟连接数超过 100 时,我的 flash 客户端保持沉默。我只是不明白为什么。
我发现,来自我的 100 多个客户端的所有消息都进入缓冲区,但 messageReceive 事件根本没有为它们触发。看起来事件队列达到了注册事件的某些限制,或者类似的东西。
我真的很难过,因为我读到更简单的服务器每秒处理 1k+ 请求。
如果有必要,我在 Windows 7 下工作。此外,我的服务器从不使用超过 2-3% 的 CPU。
我的模拟生成器:
public class ClientLoadEmulation implements Runnable {
private String host;
private int port;
private static final int minStringLength = 5;
private static final int maxStringLength = 40;
private static final int minPause = (int) (1 * 1000);
private static final int maxPause = (int) (5 * 1000);
Random rand = new Random();
public ClientLoadEmulation(String host, int port, int numThreads) {
this.host = "192.168.0.100";
this.port = 5555;
for (int i = 0; i < numThreads; ++i) {
new Thread(this).start();
try {
Thread.sleep(100);
} catch (Exception ex) {
}
}
}
@Override
public void run() {
byte buffer[] = new byte[255];
try {
Socket s = new Socket(host, port);
InputStream in = s.getInputStream();
OutputStream out = s.getOutputStream();
while (true) {
String govno = "";
...STRING GENERATION STUFF CUTTED...
ByteBuffer LENGTH_BUFFER = ByteBuffer.allocate(2);
LENGTH_BUFFER.putShort((short) govno.length());
LENGTH_BUFFER.flip();
out.write(LENGTH_BUFFER.array());
out.write(govno.getBytes("UTF-8"));
//System.out.println(Thread.currentThread() + " wrote " + govno);
int pause = minPause
+ (int) (rand.nextDouble() * (maxPause - minPause));
try {
Thread.sleep(pause);
} catch (InterruptedException ie) {
}
}
} catch (IOException ie) {
System.out.println("ERROR: " + ie.getMessage());
}
}
static public void main(String args[]) throws Exception {
new ClientLoadEmulation("127.0.0.1", 5555, 100);
}
}
(对不起我的英语水平)