Connection reset by peer?

[Clint_Knight_843]

Last night around 23:25, we lost our UNIX Agent connection in ONE Automation to one of our UNIX servers (PUNIFISCH010). The following lines I have found in the log on our end:

 

20161108/232537.818 - U0003413 Socket call 'recv(2)' returned error code '104'.

20161108/232537.818 -          Connection reset by peer

20161108/232537.818 - U0003407 Client connection '2(41)' from '127.0.0.1:53133' has logged off from the Server.

20161108/232537.822 - U0003397 Agent 'PUNIFISCH010' logged off (Client connection='2').

 Any idea of what that means or what could cause that?

[peter_grundler_automic]

This means that a TCP RST was received and the connection is now closed.  This occurs when a packet is sent from your end of the connection but the other end does not recognize the connection; it will send back a packet with the RST bit set in order to forcibly close the connection.

This can happen if the other side crashes and then comes back up or if it callsclose()on the socket while there is data from you in transit, and is an indication to you that some of the data that you previously sent may not have been received.