sockets socketchanneljava。网ConnectException:连接超时：连接

Question

我们的应用程序“有时”超时，我们有一个Java客户端连接到一个unix守护进程，出于某种原因，它不时抛出以下错误：

SocketException: Cannot establish connection to daemon
java.net.ConnectException: Connection timed out: connect
    at sun.nio.ch.Net.connect(Native Method)
    at sun.nio.ch.SocketChannelImpl.connect(Unknown Source)
    at java.nio.channels.SocketChannel.open(Unknown Source)
    at ....
    at java.lang.Thread.run(Unknown Source)

此堆栈跟踪来自以下代码：

  try
  {
    InetSocketAddress inetAddress = new InetSocketAddress(InetAddress.getByName(serverName), serverPort);
    socketChannel = SocketChannel.open(inetAddress); // <--- I think the problem is here
    pipeSck = socketChannel.socket();

  }
  catch (NoRouteToHostException e)//when the remote host cannot be reached or connection was refused
  {
    System.err.println("NoRouteToHostException: Cannot establish connection to daemon");
    e.printStackTrace();
    return 1; /* reply only with error */
  }
  catch (SocketException e)//when the remote host cannot be reached or connection was refused
  {
    System.err.println("SocketException: Cannot establish connection to daemon");
    e.printStackTrace();
    return 1; /* reply only with error */
  }

这在99%的情况下有效。。。知道我们为什么要暂停吗

谢谢

Answer 1

“连接超时”表示网络暂时关闭（这是最有可能的情况），或者，如果它没有在Windows上运行，则表示服务器的套接字积压队列已满，这可能在极端负载或拒绝服务攻击下发生

Answer 2

我同意Crollster的观点，不过您也可以检查一下主机上是否有可能导致问题的防火墙。UNIX软管是否有防火墙？有中间防火墙吗？UNIX主机是否在本地LAN上？如果没有，您是否有不稳定的互联网接入？社交很有趣。：）