This occurs when the remote side shuts the connection.
ie the application you are sending to has shut down the connection, or the connection timed out due to keepalive inactivity.
The most likely cause of the issue is the application is having issues and partially crashing.
If the time between the last sent message and the closure is some multiple of 60 seconds, then it is probably caused by keepalive.
To fix, the keepalive value on the cloverleaf server, application server, switches, and any firewalls would need to be increased to a value that is larger than the longest expected inactivity.
In either cases, the application should be fixed to handle whatever is causing the issue.
If the application can’t/won’t be fixed, then I’d implement a regular job that checks the status of that port and restart the app if it is not connected for a period of time.
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