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unknown error initiating tcp/ip socket

asked 2011-10-10 13:36:02 -0500

Tom Sgouros gravatar image

updated 2011-10-16 08:10:42 -0500

kwc gravatar image

Can anyone tell me what this error implies?

[rospy.internal][WARNING] 2011-09-30 12:02:32,391: Unknown error initiating TCP/IP socket to tahoma:56716 (http://tahoma:32771/): Traceback (most recent call last):
  File "/opt/ros/diamondback/stacks/ros_comm/clients/rospy/src/rospy/impl/tcpros_base.py", line 474, in connect self.read_header()
  File "/opt/ros/diamondback/stacks/ros_comm/clients/rospy/src/rospy/impl/tcpros_base.py", line 526, in read_header
    self._validate_header(read_ros_handshake_header(self.socket, self.read_buff, self.protocol.buff_size))
  File "/opt/ros/diamondback/ros/core/roslib/src/roslib/network.py", line 350, in read_ros_handshake_header
    d = sock.recv(buff_size)
error: [Errno 104] Connection reset by peer

I get this infrequently, but often enough to be a nuisance, say after ten or twenty minutes of operation. The message implies that it's only a warning, but one of the nodes on which I see it becomes unaccountably silent when it happens.

More context: The node that suffers this error is subscribed only to messages issued from the same machine, and is publishing messages that will be read only on the same machine, so I'm not really sure what a TCP/IP socket has to do with anything here. There is another machine in the system publishing to a topic read by a node on this machine, but that is (I think) independent of the node that fails.

I obviously understand this is some kind of communication issue and that's why the node becomes silent. What I don't understand is why there is network communication going on at all, and what might be going wrong.

Thank you for any insight you have.

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Comments

Have you solved this error? If so, tell me please. I would appreciate it very much. thank you.

lyz gravatar image lyz  ( 2019-02-18 00:19:28 -0500 )edit

Since the question is really old (8 years) you probably won't get a response from the author. I would suggest you to open a new question, you will have more chances to have someone answering you.

Delb gravatar image Delb  ( 2019-02-18 03:44:48 -0500 )edit

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answered 2012-05-15 10:43:40 -0500

Cody gravatar image

All communication between ROS nodes, even on the same computer, uses TCP/IP (nodelets are the exception).

The [Errno 104] indicates a ECONNRESET error, ie: "connection reset by peer".

A packet trace (via tcpdump/wireshark) will be needed to diagnose this further.

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Asked: 2011-10-10 13:36:02 -0500

Seen: 4,231 times

Last updated: Feb 18 '19