suging闲谈-netty 的异步非阻塞IO线程与业务线程分离

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前言

surging 对外沉寂了一段时间了，但是作者并没有闲着，而是针对于客户的需要添加了不少功能，也给我带来了不少外快收益, 就比如协议转化，consul 的watcher 机制，JAVA版本，skywalking 升级支持8.0，.升级NET 6.0 ，而客户自己扩展支持服务编排流程引擎，后期客户还需要扩展定制coap ，XMPP等协议。而今天写这篇文章的目的针对于修改基于netty 的异步非阻塞业务逻辑操作

问题描述

年前客户把JAVA版本进行了测试，产生了不少问题，客户也比较茫然，因为有内存泄漏，通过jmeter压测，并发始终上不来，通过半个月的努力，终于把问题解决了，预估JAVA版本并发能达到2万左右，以下是客户通过设置jmeter压测实例

解决方案

当客户把问题抛给我后，我第一反应是IO线程被阻塞造成的，而这样就可以把问题定位在netty 的处理上，而处理server 端代码是NettyServerMessageListener，而其中ServerHandler的channelRead是处理业务逻辑的，在这当中我是通过ThreadPoolExecutor执行异步处理，可以看看NettyServerMessageListener代码：

public class NettyServerMessageListener implements IMessageListener {
private Thread thread;
private static final Logger logger = LoggerFactory.getLogger(NettyServerMessageListener.class);
private ChannelFuture channel;
private final ITransportMessageDecoder transportMessageDecoder;
private final ITransportMessageEncoder transportMessageEncoder;
ReceivedDelegate Received = new ReceivedDelegate();
@Inject
public NettyServerMessageListener( ITransportMessageCodecFactory codecFactory)
{
this.transportMessageEncoder = codecFactory.GetEncoder();
this.transportMessageDecoder = codecFactory.GetDecoder();
} public void StartAsync(final String serverAddress) {
thread = new Thread(new Runnable() {
int parallel = Runtime.getRuntime().availableProcessors();
final DefaultEventLoopGroup eventExecutors = new DefaultEventLoopGroup(parallel);
ThreadFactory threadFactory = new DefaultThreadFactory("rpc-netty", true);
public void run() {
String[] array = serverAddress.split(":");
logger.debug("准备启动服务主机，监听地址：" + array[0] + "" + array[1] + "。");
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup(parallel,threadFactory);
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup, workerGroup).option(ChannelOption.SO_BACKLOG,128)
.childOption(ChannelOption.SO_KEEPALIVE,true).childOption(ChannelOption.TCP_NODELAY, true).channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel socketChannel) throws Exception {
socketChannel.pipeline()
.addLast(new LengthFieldPrepender(4))
.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4))
.addLast(new ServerHandler(eventExecutors,new ReadAction<ChannelHandlerContext, TransportMessage>() {
@Override
public void run() {
IMessageSender sender = new NettyServerMessageSender(transportMessageEncoder, this.parameter);
onReceived(sender, this.parameter1);
}
},transportMessageDecoder)
);
}
})
.option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
try { String host = array[0];
int port = Integer.parseInt(array[1]);
channel = bootstrap.bind(host, port).sync();
logger.debug("服务主机启动成功，监听地址：" + serverAddress + "。");
} catch (Exception e) {
if (e instanceof InterruptedException) {
logger.info("Rpc server remoting server stop");
} else {
logger.error("Rpc server remoting server error", e);
} }
}
});
thread.start();
} @Override
public ReceivedDelegate getReceived() {
return Received;
} public void onReceived(IMessageSender sender, TransportMessage message) {
if (Received == null)
return;
Received.notifyX(sender,message);
} private class ReadAction<T,T1> implements Runnable
{
public T parameter;
public T1 parameter1;
public void setParameter( T tParameter,T1 tParameter1) {
parameter = tParameter;
parameter1 = tParameter1;
} @Override
public void run() { }
} private class ServerHandler extends ChannelInboundHandlerAdapter {
private final DefaultEventLoopGroup serverHandlerPool;
private final ReadAction<ChannelHandlerContext, TransportMessage> serverRunnable;
private final ITransportMessageDecoder transportMessageDecoder; public ServerHandler(final DefaultEventLoopGroup threadPoolExecutor, ReadAction<ChannelHandlerContext, TransportMessage> runnable,
ITransportMessageDecoder transportMessageDecoder) {
this.serverHandlerPool = threadPoolExecutor;
this.serverRunnable = runnable;
this.transportMessageDecoder = transportMessageDecoder;
} @Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
logger.warn("与服务器：" + ctx.channel().remoteAddress() + "通信时发送了错误。");
ctx.close();
} @Override
public void channelReadComplete(ChannelHandlerContext context) {
context.flush();
} @Override
public void channelRead(ChannelHandlerContext channelHandlerContext, Object message) throws Exception {
ByteBuf buffer = (ByteBuf) message;
try {
byte[] data = new byte[buffer.readableBytes()];
buffer.readBytes(data);
serverHandlerPool.execute(() -> {
TransportMessage transportMessage = null;
try {
transportMessage = transportMessageDecoder.Decode(data);
} catch (IOException e) {
e.printStackTrace();
}
serverRunnable.setParameter(channelHandlerContext, transportMessage);
serverRunnable.run();
});
}
finally {
ReferenceCountUtil.release(message);
}
}
}
}

ThreadPoolExecutor代码：

public static ThreadPoolExecutor makeServerThreadPool(final String serviceName, int corePoolSize, int maxPoolSize) {
ThreadPoolExecutor serverHandlerPool = new ThreadPoolExecutor(
corePoolSize,
maxPoolSize,
60L,
TimeUnit.SECONDS,
new ArrayBlockingQueue<Runnable>( 10000));
/*
new LinkedBlockingQueue<Runnable>(10000),
r -> new Thread(r, "netty-rpc-" + serviceName + "-" + r.hashCode()),
new ThreadPoolExecutor.AbortPolicy());*/ return serverHandlerPool;
}

后面通过查找官方的文档发现以下addLast是IO线程阻塞调用

.addLast(new ServerHandler(eventExecutors,new ReadAction<ChannelHandlerContext, TransportMessage>() {
@Override
public void run() {
IMessageSender sender = new NettyServerMessageSender(transportMessageEncoder, this.parameter);
onReceived(sender, this.parameter1);
}
},transportMessageDecoder)

后面通过使用EventExecutorGroup把IO线程与业务线程进行分离，把耗时业务处理添加到EventExecutorGroup进行处理，首先EventExecutorGroup代码如下

public static final EventExecutorGroup execThreadPool = new DefaultEventExecutorGroup( Runtime.getRuntime().availableProcessors()*2,
(ThreadFactory) r -> {
Thread thread = new Thread(r);
thread.setName("custom-tcp-exec-"+r.hashCode());
return thread;
},
100000,
RejectedExecutionHandlers.reject()
);

而addLast的ServerHandler添加了EventExecutorGroup，最新的NettyServerMessageListener代码如下：

public class NettyServerMessageListener implements IMessageListener {
private Thread thread;
private static final Logger logger = LoggerFactory.getLogger(NettyServerMessageListener.class);
private ChannelFuture channel;
private final ITransportMessageDecoder transportMessageDecoder;
private final ITransportMessageEncoder transportMessageEncoder;
ReceivedDelegate Received = new ReceivedDelegate();
@Inject
public NettyServerMessageListener( ITransportMessageCodecFactory codecFactory)
{
this.transportMessageEncoder = codecFactory.GetEncoder();
this.transportMessageDecoder = codecFactory.GetDecoder();
} public void StartAsync(final String serverAddress) {
thread = new Thread(new Runnable() {
public void run() {
String[] array = serverAddress.split(":");
logger.debug("准备启动服务主机，监听地址：" + array[0] + "" + array[1] + "。");
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel socketChannel) throws Exception {
socketChannel.pipeline()
.addLast(new LengthFieldPrepender(4))
.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4))
.addLast(ThreadPoolUtil.execThreadPool, "handler",new ServerHandler(new ReadAction<ChannelHandlerContext, TransportMessage>() {
@Override
public void run() {
IMessageSender sender = new NettyServerMessageSender(transportMessageEncoder, this.parameter);
onReceived(sender, this.parameter1);
}
},transportMessageDecoder)
);
}
})
.option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
try { String host = array[0];
int port = Integer.parseInt(array[1]);
channel = bootstrap.bind(host, port).sync();
logger.debug("服务主机启动成功，监听地址：" + serverAddress + "。");
} catch (Exception e) {
if (e instanceof InterruptedException) {
logger.info("Rpc server remoting server stop");
} else {
logger.error("Rpc server remoting server error", e);
} }
}
});
thread.start();
} @Override
public ReceivedDelegate getReceived() {
return Received;
} public void onReceived(IMessageSender sender, TransportMessage message) {
if (Received == null)
return;
Received.notifyX(sender,message);
} private class ReadAction<T,T1> implements Runnable
{
public T parameter;
public T1 parameter1;
public void setParameter( T tParameter,T1 tParameter1) {
parameter = tParameter;
parameter1 = tParameter1;
} @Override
public void run() { }
} private class ServerHandler extends ChannelInboundHandlerAdapter { private final ReadAction<ChannelHandlerContext, TransportMessage> serverRunnable;
private final ITransportMessageDecoder transportMessageDecoder; public ServerHandler(ReadAction<ChannelHandlerContext, TransportMessage> runnable,
ITransportMessageDecoder transportMessageDecoder) { this.serverRunnable = runnable;
this.transportMessageDecoder = transportMessageDecoder;
} @Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
logger.warn("与服务器：" + ctx.channel().remoteAddress() + "通信时发送了错误。");
ctx.close();
} @Override
public void channelReadComplete(ChannelHandlerContext context) {
context.flush();
} @Override
public void channelRead(ChannelHandlerContext channelHandlerContext, Object message) throws Exception {
ByteBuf buffer = (ByteBuf) message;
try {
byte[] data = new byte[buffer.readableBytes()];
buffer.readBytes(data);
TransportMessage transportMessage = transportMessageDecoder.Decode(data);
serverRunnable.setParameter(channelHandlerContext, transportMessage);
serverRunnable.run();
}
finally {
ReferenceCountUtil.release(message);
}
}
}
}

通过以上修改，再通过jmeter压测已经不会出现timeout 问题，就连stage 网关-》.NET微服务-》JAVA微服务都没有Time out问题产生，jmeter的user thread拉长到2000也没有出现问题。

通过以上思路把.NET版本的surging 社区版本也进行了修改，已经提交到github，首先把ServiceHost中的serverMessageListener.Received 中的Task.Run移除，ServerHandler中ChannelRead进行移除，然后addLast的ServerHandler添加了EventExecutorGroup.通过以上修改再通过压测发现可以支持20万+ ，也未发现内存泄漏问题，执行client 1万次，服务端cpu 在6%左右，响应速度在1.1秒左右，可以开启多个surging 的client 进行压测，cpu 会叠加上升，响应速度没有影响，以下是执行1万次压测

surging 社区版本开源地址

总结

通过5年研发，surging 从原来的最初的基于netty 的RPC发展到现在可以支持多协议，多语言的异构微服务引擎，不仅是技术的提高，也带来名利的收益，只要不断坚持，终究能看到成果，我也会一直更新，为企业和社区用户带来自己的绵薄之力，让企业能更好的掌握微服务解决方案，已解决现在行业各种不同的业务需求。