Question

netty 真的有那么高并发吗

Answer 1

我就是用demo那种方式写的，netty自带线程池的，我就没有用自己的线程处理了，而且占cpu资源太猛了，4个线程就能占CPU100%了，客户端测试基本不占CPU，CPU资源基都被netty框架占满了，这个是怎么回事呢？
代码如下：
public class NettyServer {

public static final ThreadLocal<PacketCrypt> session = new ThreadLocal<PacketCrypt>();
// MemoryAwareThreadPoolExecutor
// OrderedMemoryAwareThreadPoolExecutor
// ExecutionHandler executionHandler = new ExecutionHandler(
// new MemoryAwareThreadPoolExecutor(16, 1048576, 1048576))

private static final ImmediateEventExecutor iee = ImmediateEventExecutor.INSTANCE;

public static void startServer(int port,int workerCount) throws InterruptedException{

//取默认

EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();

b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
PacketCrypt pc = null;
pc = session.get();
if (pc == null){
try {
pc = new PacketCrypt();
pc.getCryptAES().importKey(PacketCrypt.INITKEY,PacketCrypt.INITIV);
session.set(pc);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
ConnectionContext connectionContext = null;
connectionContext = new ConnectionContext(pc);
connectionContext.setChannel(ch);
// ch.pipeline().addLast(new WriteTimeoutHandler(60));
// // 注册两个OutboundHandler，执行顺序为注册顺序的逆序，所以应该是OutboundHandler2 OutboundHandler1
// ch.pipeline().addLast(new MessageEncoder());
// 注册两个InboundHandler，执行顺序为注册顺序，所以应该是InboundHandler1 InboundHandler2
// ch.pipeline().addLast(new ReadTimeoutHandler(60));
ch.pipeline().addLast(ImmediateEventExecutor.INSTANCE,new MessageDecoder(connectionContext));
// ch.pipeline().addLast(new DepacketAdapter(connectionContext));
ch.pipeline().addLast(ImmediateEventExecutor.INSTANCE,new BusinessAdapter());
}

});
b.option(ChannelOption.SO_BACKLOG, 1024) ;
// b.childOption("child.reuseAddress", true);
b.childOption(ChannelOption.TCP_NODELAY,true);
b.childOption(ChannelOption.SO_KEEPALIVE,true);
// b.childOption(ChannelOption.RCVBUF_ALLOCATOR, new FixedRecvByteBufAllocator(4096));
// Bind and start to accept incoming connections.
ChannelFuture f = b.bind(port).sync();
TraceLog.info(" 系统启动完成.");
// Wait until the server socket is closed.
// In this example, this does not happen, but you can do that to gracefully
// shut down your server.
f.channel().closeFuture().sync();
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}

}

}

public class MessageDecoder extends ChannelInboundHandlerAdapter {
private ConnectionContext connectionContext;

public MessageDecoder(ConnectionContext connectionContext){

this.connectionContext = connectionContext;

}

@Override

public void channelRead(ChannelHandlerContext ctx, Object msg)

throws Exception {
// SimpleChannelInboundHandler

ByteBuf buf = (ByteBuf) msg;
// System.out.println(buf.readableBytes());

// Make sure if the length field was received.

if (buf.readableBytes() < 4) {

// The length field was not received yet - return.

// This method will be invoked again when more packets are

// received and appended to the buffer.

return ;

}

// The length field is in the buffer.

// Mark the current buffer position before reading the length field

// because the whole frame might not be in the buffer yet.

// We will reset the buffer position to the marked position if

// there's not enough bytes in the buffer.

buf.markReaderIndex(); // Read the length field.

byte[] lenbytes = new byte[4];

buf.readBytes(lenbytes);

int length = ( (lenbytes[3] & 0xFF) << 24 ) | ( (lenbytes[2] & 0xFF) << 16 )

| ( (lenbytes[1] & 0xFF) << 8 ) | ( (lenbytes[0] & 0xFF) );
// System.out.println(buf.readableBytes());

if (length < MINLEN){

buf.clear();
ctx.close();
return;

}

// Make sure if there's enough bytes in the buffer.

if (buf.readableBytes() < length + 9) {// The whole bytes were not received yet - return null.

buf.resetReaderIndex();

return;

}

try{

// There's enough bytes in the buffer. Read it.

byte[] body = new byte[length];

byte[] sign = new byte[9];

// Successfully decoded a frame. Return the decoded frame.

buf.readBytes(body);

buf.readBytes(sign);

MessagePacket mp = new MessagePacket(connectionContext, body, sign);

connectionContext.incPackNum();

ctx.fireChannelRead(mp);

}finally{

buf.release();

}

}

private final static int MINLEN = "{\"ver\":\"1\",\"av\":\"1\",\"cf\":10001,\"tc\":\"tc\",\"md\":\"md\"}".length();
}

public class BusinessAdapter extends ChannelInboundHandlerAdapter {

private MessagePacket mp;

private PacketCrypt pc = null;

private TradeContextImp tradeContextImp = null;

private SocketChannel sc = null;

public BusinessAdapter() throws Exception{

pc = new PacketCrypt();

}

private void doExecuteMessage(){

sc = mp.getConnectionContext().getChannel();

//如果连接已关闭则不处理该包

if (!sc.isActive()) return;

//解析包体

try {

tradeContextImp = new TradeContextImp(pc,mp);

mp.getConnectionContext().setKeepAlive(false);

//处理业务

byte[] resp = doExecute();

if (!sc.isActive()) return;

ChannelHandlerContext chc = mp.getConnectionContext().getChannelHandlerContext();

ByteBuf bb = chc.alloc().directBuffer(resp.length);

bb.writeBytes(resp);

//如果连接已关闭则不处理该包

chc.writeAndFlush(bb);
// chc.fireChannelWritabilityChanged();

} catch (PacketException e) {

sc.close();

} catch (IOException e) {

sc.close();

}

}

/**

* 交易接口参数类型数组定义

*/

private static Class<?>[] invokeParamsClass = new Class<?>[]{TradeContext.class};

@Override

public void channelRead(ChannelHandlerContext ctx, Object msg)

throws Exception {
// System.out.println("enter business adapter time: " + new Date());

mp = (MessagePacket)msg;

mp.getConnectionContext().setChannelHandlerContext(ctx);

doExecuteMessage();

}

@Override

public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
// ctx.flush();

}

@Override

public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)

throws Exception {

ctx.close();

}

}

Answer 2

你这个代码没有一点条理性，太乱了，我的服务端代码并发连接几万个，服务器资源使用率还不到60%。