Question

dubbo服务无故停止怎么回事

Answer 1

NettyServer在构造函数中会调用
ChannelHandlers.wrap(handler, ExecutorUtil.setThreadName(url, SERVER_THREAD_POOL_NAME))
方法将handler进行包装，包装成MultiMessageHandler的一个对象。在下面红色代码中会判断handler是否是WrappedChannelHandler对象，只有是的时候才会对executor对象复值。因为MultiMessageHandler对象不是WrappedChannelHandler的子类，所以executor为空。
当滑旅NettyServer的close方法被调用的时早猜候，会调用ExecutorUtil.gracefulShutdown方法，gracefulShutdown方法只有executor不为空时才会等待线程信睁凳池关闭
public abstract class AbstractServer extends AbstractEndpoint implements Server {
public AbstractServer(URL url, ChannelHandler handler) throws RemotingException {
super(url, handler);
localAddress = getUrl().toInetSocketAddress();
String host = url.getParameter(Constants.ANYHOST_KEY, false)
|| NetUtils.isInvalidLocalHost(getUrl().getHost())
? NetUtils.ANYHOST : getUrl().getHost();
bindAddress = new InetSocketAddress(host, getUrl().getPort());
this.accepts = url.getParameter(Constants.ACCEPTS_KEY, Constants.DEFAULT_ACCEPTS);
this.idleTimeout = url.getParameter(Constants.IDLE_TIMEOUT_KEY, Constants.DEFAULT_IDLE_TIMEOUT);
try {
doOpen();
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);
}
if (handler instanceof WrappedChannelHandler ){
executor = ((WrappedChannelHandler)handler).getExecutor();
}
}
public void close(int timeout) {
ExecutorUtil.gracefulShutdown(executor ,timeout);
close();
}
}
2. 服务端改动：
修改了AbstractServer类的红色部分
public abstract class AbstractServer extends AbstractEndpoint implements Server {
private static final Logger logger = LoggerFactory.getLogger(AbstractServer.class);
private InetSocketAddress localAddress;
private InetSocketAddress bindAddress;
private int accepts;
private int idleTimeout = 600; //600 seconds
protected static final String SERVER_THREAD_POOL_NAME ="DubboServerHandler";
ExecutorService executor;
public AbstractServer(URL url, ChannelHandler handler) throws RemotingException {
super(url, handler);
localAddress = getUrl().toInetSocketAddress();
String host = url.getParameter(Constants.ANYHOST_KEY, false)
|| NetUtils.isInvalidLocalHost(getUrl().getHost())
? NetUtils.ANYHOST : getUrl().getHost();
bindAddress = new InetSocketAddress(host, getUrl().getPort());
this.accepts = url.getParameter(Constants.ACCEPTS_KEY, Constants.DEFAULT_ACCEPTS);
this.idleTimeout = url.getParameter(Constants.IDLE_TIMEOUT_KEY, Constants.DEFAULT_IDLE_TIMEOUT);
try {
doOpen();
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);
}
try {
recycleToGetExecutor(handler);
} catch (Exception e) {
logger.error("recycle to get executor failed");
}
}
private void recycleToGetExecutor(ChannelHandler handler) throws NoSuchFieldException, IllegalAccessException {
if(handler == null)
{
return;
}