Dubbo源码-10-Transporter
一 接口
@SPI("netty")
public interface Transporter {
/**
* Bind a server.
*
* @param url server url
* @param handler
* @return server
* @throws RemotingException
* @see com.alibaba.dubbo.remoting.Transporters#bind(URL, ChannelHandler...)
*/
@Adaptive({Constants.SERVER_KEY, Constants.TRANSPORTER_KEY})
Server bind(URL url, ChannelHandler handler) throws RemotingException;
/**
* Connect to a server.
*
* @param url server url
* @param handler
* @return client
* @throws RemotingException
* @see com.alibaba.dubbo.remoting.Transporters#connect(URL, ChannelHandler...)
*/
@Adaptive({Constants.CLIENT_KEY, Constants.TRANSPORTER_KEY})
Client connect(URL url, ChannelHandler handler) throws RemotingException;
}
扩展实现
- 默认NettyTransporter
- URL中配置项
- bind方法
- server
- transporter
- connect方法
- client
- transporter
- bind方法
二 Transporter$Adaptive
package com.alibaba.dubbo.remoting;
import com.alibaba.dubbo.common.extension.ExtensionLoader;
public class Transporter$Adaptive implements com.alibaba.dubbo.remoting.Transporter {
public com.alibaba.dubbo.remoting.Client connect(com.alibaba.dubbo.common.URL arg0, com.alibaba.dubbo.remoting.ChannelHandler arg1) throws com.alibaba.dubbo.remoting.RemotingException {
if (arg0 == null) throw new IllegalArgumentException("url == null");
com.alibaba.dubbo.common.URL url = arg0;
String extName = url.getParameter("client", url.getParameter("transporter", "netty"));
if (extName == null)
throw new IllegalStateException("Fail to get extension(com.alibaba.dubbo.remoting.Transporter) name from url(" + url.toString() + ") use keys([client, transporter])");
com.alibaba.dubbo.remoting.Transporter extension = (com.alibaba.dubbo.remoting.Transporter) ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.remoting.Transporter.class).getExtension(extName);
return extension.connect(arg0, arg1);
}
public com.alibaba.dubbo.remoting.Server bind(com.alibaba.dubbo.common.URL arg0, com.alibaba.dubbo.remoting.ChannelHandler arg1) throws com.alibaba.dubbo.remoting.RemotingException {
if (arg0 == null) throw new IllegalArgumentException("url == null");
com.alibaba.dubbo.common.URL url = arg0;
String extName = url.getParameter("server", url.getParameter("transporter", "netty"));
if (extName == null)
throw new IllegalStateException("Fail to get extension(com.alibaba.dubbo.remoting.Transporter) name from url(" + url.toString() + ") use keys([server, transporter])");
com.alibaba.dubbo.remoting.Transporter extension = (com.alibaba.dubbo.remoting.Transporter) ExtensionLoader.getExtensionLoader(com.alibaba.dubbo.remoting.Transporter.class).getExtension(extName);
return extension.bind(arg0, arg1);
}
}
实现
-
SPI指定的默认实现是netty
-
自适应扩展点
-
URL中配置server
-
URL中配置transporter
-
三 实现
1 NettyTransporter
1.1 生产者服务导出
@Override
public Server bind(URL url, ChannelHandler listener) throws RemotingException {
return new NettyServer(url, listener);
}
// NettyServer.java
public NettyServer(URL url, ChannelHandler handler) throws RemotingException {
// 调用父类构造方法 回调子类的实现doOpen(...)
super(url, ChannelHandlers.wrap(handler, ExecutorUtil.setThreadName(url, SERVER_THREAD_POOL_NAME)));
}
// AbstractServer.java
public AbstractServer(URL url, ChannelHandler handler) throws RemotingException {
super(url, handler);
localAddress = getUrl().toInetSocketAddress(); // /192.168.0.11:20880
String bindIp = getUrl().getParameter(Constants.BIND_IP_KEY, getUrl().getHost()); // 192.168.0.1
int bindPort = getUrl().getParameter(Constants.BIND_PORT_KEY, getUrl().getPort()); // 20880
if (url.getParameter(Constants.ANYHOST_KEY, false) || NetUtils.isInvalidLocalHost(bindIp)) {
bindIp = NetUtils.ANYHOST;
}
bindAddress = new InetSocketAddress(bindIp, bindPort);
this.accepts = url.getParameter(Constants.ACCEPTS_KEY, Constants.DEFAULT_ACCEPTS);
this.idleTimeout = url.getParameter(Constants.IDLE_TIMEOUT_KEY, Constants.DEFAULT_IDLE_TIMEOUT);
try {
this.doOpen(); // 模板方法 实现在子类
if (logger.isInfoEnabled()) {
logger.info("Start " + getClass().getSimpleName() + " bind " + getBindAddress() + ", export " + getLocalAddress());
}
} catch (Throwable t) {
throw new RemotingException(url.toInetSocketAddress(), null, "Failed to bind " + getClass().getSimpleName()
+ " on " + getLocalAddress() + ", cause: " + t.getMessage(), t);
}
//fixme replace this with better method
DataStore dataStore = ExtensionLoader.getExtensionLoader(DataStore.class).getDefaultExtension();
executor = (ExecutorService) dataStore.get(Constants.EXECUTOR_SERVICE_COMPONENT_KEY, Integer.toString(url.getPort()));
}
// NettyServer.java
@Override
protected void doOpen() throws Throwable { // 典型的netty编程
bootstrap = new ServerBootstrap();
bossGroup = new NioEventLoopGroup(1, new DefaultThreadFactory("NettyServerBoss", true));
workerGroup = new NioEventLoopGroup(getUrl().getPositiveParameter(Constants.IO_THREADS_KEY, Constants.DEFAULT_IO_THREADS),
new DefaultThreadFactory("NettyServerWorker", true));
final NettyServerHandler nettyServerHandler = new NettyServerHandler(getUrl(), this);
channels = nettyServerHandler.getChannels();
bootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childOption(ChannelOption.TCP_NODELAY, Boolean.TRUE)
.childOption(ChannelOption.SO_REUSEADDR, Boolean.TRUE)
.childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
.childHandler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel ch) throws Exception {
NettyCodecAdapter adapter = new NettyCodecAdapter(getCodec(), getUrl(), NettyServer.this);
ch.pipeline()//.addLast("logging",new LoggingHandler(LogLevel.INFO))//for debug
.addLast("decoder", adapter.getDecoder())
.addLast("encoder", adapter.getEncoder())
.addLast("handler", nettyServerHandler);
}
});
// bind
ChannelFuture channelFuture = bootstrap.bind(getBindAddress());
channelFuture.syncUninterruptibly();
channel = channelFuture.channel();
}
1.2 消费者服务引用
// NettyTransporter.java
@Override
public Client connect(URL url, ChannelHandler listener) throws RemotingException {
return new NettyClient(url, listener);
}
// NettyClient.java
public NettyClient(final URL url, final ChannelHandler handler) throws RemotingException {
super(url, wrapChannelHandler(url, handler));
}
// AbstractClient.java
public AbstractClient(URL url, ChannelHandler handler) throws RemotingException {
super(url, handler);
send_reconnect = url.getParameter(Constants.SEND_RECONNECT_KEY, false);
shutdown_timeout = url.getParameter(Constants.SHUTDOWN_TIMEOUT_KEY, Constants.DEFAULT_SHUTDOWN_TIMEOUT);
// The default reconnection interval is 2s, 1800 means warning interval is 1 hour.
reconnect_warning_period = url.getParameter("reconnect.waring.period", 1800);
try {
this.doOpen(); // 抽象 实现由子类关注
} catch (Throwable t) {
close();
throw new RemotingException(url.toInetSocketAddress(), null,
"Failed to start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress()
+ " connect to the server " + getRemoteAddress() + ", cause: " + t.getMessage(), t);
}
try {
// connect.
connect();
if (logger.isInfoEnabled()) {
logger.info("Start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress() + " connect to the server " + getRemoteAddress());
}
} catch (RemotingException t) {
if (url.getParameter(Constants.CHECK_KEY, true)) {
close();
throw t;
} else {
logger.warn("Failed to start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress()
+ " connect to the server " + getRemoteAddress() + " (check == false, ignore and retry later!), cause: " + t.getMessage(), t);
}
} catch (Throwable t) {
close();
throw new RemotingException(url.toInetSocketAddress(), null,
"Failed to start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress()
+ " connect to the server " + getRemoteAddress() + ", cause: " + t.getMessage(), t);
}
boolean shouldShareExecutor = url.getParameter(SHARE_EXECUTOR_KEY, false);
String portKey = shouldShareExecutor ? SHARED_CONSUMER_EXECUTOR_PORT : Integer.toString(url.getPort());
executor = (ExecutorService) ExtensionLoader.getExtensionLoader(DataStore.class)
.getDefaultExtension().get(Constants.CONSUMER_SIDE, portKey);
if (!shouldShareExecutor) {
ExtensionLoader.getExtensionLoader(DataStore.class)
.getDefaultExtension().remove(Constants.CONSUMER_SIDE, portKey);
}
}
// AbstractClient.java
protected void connect() throws RemotingException {
connectLock.lock();
try {
if (isConnected()) {
return;
}
initConnectStatusCheckCommand();
doConnect(); // 抽象 实现由子类关注
if (!isConnected()) {
throw new RemotingException(this, "Failed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion()
+ ", cause: Connect wait timeout: " + getConnectTimeout() + "ms.");
} else {
if (logger.isInfoEnabled()) {
logger.info("Successed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion()
+ ", channel is " + this.getChannel());
}
}
reconnect_count.set(0);
reconnect_error_log_flag.set(false);
} catch (RemotingException e) {
throw e;
} catch (Throwable e) {
throw new RemotingException(this, "Failed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion()
+ ", cause: " + e.getMessage(), e);
} finally {
connectLock.unlock();
}
}
上层抽象声明了两个方法
- doOpen(...)
- doConeect(...)
实现都在NettyClient中
1.2.1 open
// NettyClient.java
@Override
protected void doOpen() throws Throwable {
final NettyClientHandler nettyClientHandler = new NettyClientHandler(getUrl(), this);
bootstrap = new Bootstrap();
bootstrap.group(nioEventLoopGroup)
.option(ChannelOption.SO_KEEPALIVE, true)
.option(ChannelOption.TCP_NODELAY, true)
.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
//.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, getTimeout())
.channel(NioSocketChannel.class);
if (getConnectTimeout() < 3000) {
bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 3000);
} else {
bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, getConnectTimeout());
}
bootstrap.handler(new ChannelInitializer() {
@Override
protected void initChannel(Channel ch) throws Exception {
NettyCodecAdapter adapter = new NettyCodecAdapter(getCodec(), getUrl(), NettyClient.this);
ch.pipeline()//.addLast("logging",new LoggingHandler(LogLevel.INFO))//for debug
.addLast("decoder", adapter.getDecoder())
.addLast("encoder", adapter.getEncoder())
.addLast("handler", nettyClientHandler);
String socksProxyHost = ConfigUtils.getProperty(SOCKS_PROXY_HOST);
if(socksProxyHost != null) {
int socksProxyPort = Integer.parseInt(ConfigUtils.getProperty(SOCKS_PROXY_PORT, DEFAULT_SOCKS_PROXY_PORT));
Socks5ProxyHandler socks5ProxyHandler = new Socks5ProxyHandler(new InetSocketAddress(socksProxyHost, socksProxyPort));
ch.pipeline().addFirst(socks5ProxyHandler);
}
}
});
}
1.2.2 connect
// NettyClient.java
@Override
protected void doConnect() throws Throwable {
long start = System.currentTimeMillis();
ChannelFuture future = bootstrap.connect(getConnectAddress());
try {
boolean ret = future.awaitUninterruptibly(getConnectTimeout(), TimeUnit.MILLISECONDS);
if (ret && future.isSuccess()) {
Channel newChannel = future.channel();
try {
// Close old channel
Channel oldChannel = NettyClient.this.channel; // copy reference
if (oldChannel != null) {
try {
if (logger.isInfoEnabled()) {
logger.info("Close old netty channel " + oldChannel + " on create new netty channel " + newChannel);
}
oldChannel.close();
} finally {
NettyChannel.removeChannelIfDisconnected(oldChannel);
}
}
} finally {
if (NettyClient.this.isClosed()) {
try {
if (logger.isInfoEnabled()) {
logger.info("Close new netty channel " + newChannel + ", because the client closed.");
}
newChannel.close();
} finally {
NettyClient.this.channel = null;
NettyChannel.removeChannelIfDisconnected(newChannel);
}
} else {
NettyClient.this.channel = newChannel;
}
}
} else if (future.cause() != null) {
throw new RemotingException(this, "client(url: " + getUrl() + ") failed to connect to server "
+ getRemoteAddress() + ", error message is:" + future.cause().getMessage(), future.cause());
} else {
throw new RemotingException(this, "client(url: " + getUrl() + ") failed to connect to server "
+ getRemoteAddress() + " client-side timeout "
+ getConnectTimeout() + "ms (elapsed: " + (System.currentTimeMillis() - start) + "ms) from netty client "
+ NetUtils.getLocalHost() + " using dubbo version " + Version.getVersion());
}
} finally {
if (!isConnected()) {
//future.cancel(true);
}
}
}
