Connection refused error when writing to socket?

Posted by Li Peng on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/Connection-refused-error-when-writing-to-socket-tp11372.html

Hi there,

I'm trying to test a couple of things by having my stream write to a
socket, but it keeps failing to connect (I'm trying to have a stream
write to a socket, and have another stream read from that socket).

Caused by: java.net.ConnectException: Connection refused (Connection refused)

at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
at java.net.Socket.connect(Socket.java:589)
at org.apache.flink.streaming.api.functions.source.SocketTextStreamFunction.run(SocketTextStreamFunction.java:96)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:80)
at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:53)
at org.apache.flink.streaming.runtime.tasks.SourceStreamTask.run(SourceStreamTask.java:56)
at org.apache.flink.streaming.runtime.tasks.StreamTask.invoke(StreamTask.java:267)
at org.apache.flink.runtime.taskmanager.Task.run(Task.java:642)
at java.lang.Thread.run(Thread.java:745)

I tried writeToSocket(parameterTool.get("localhost"),
parameterTool.getInt(9000), new SimpleStringSchema), and even a custom
sink:

addSink(w => {
  val ia = InetAddress.getByName("localhost")
  val socket = new Socket(ia, 9000)
  val outStream = socket.getOutputStream
  val out = new PrintWriter(new BufferedWriter(new
OutputStreamWriter(outStream)))
  out.println(w)
  out.flush()
  out.close()
})

But none of this seem to work. I'm fairly sure I setup the server
correctly since I can connect it to via a telnet and other dummy
echoclients I wrote. I can also have my data stream read from that
same socket without any issues, but I can't seem to tell my stream to
write to this socket without the above connection refused error
showing up. Is there some nuance here I'm missing?

Thanks!