Receiving the following messages in the XCOMLOG:
XCOMM1467E OMVS Error: EDC8124I Socket not connected. (errno2=0x749B0000)
XCOMM0780E Txpi 234: Error 1124 from getpeername; length : 28
XCOMM0666E TxpiInitConnection FAILED - UNKNOWN PARTNER - TERMINATING CONNECTION
What is causing the messages and from where are they comming?
Port scanning is producing the error messages in this case. The messages are produced because the partner is closing the connection before XCOM can complete the connection in the server, hence why it appears as an unidentified IP address for the incoming connection.
Release : 12.0
Component : XCOM Data Transport for z/OS
Contact the team responsible for setting the port scans and verify if additional scan methods have been added which include closing the port immediately after initiating a connection.
Make sure that those port scans are throttled as to not affect or overload the server, since this can comprise a high percentage of the work the XCOM server is doing. Aggressive scans can be counterproductive and affect your production workload.
Always be on the lookout for such messages and involve the team responsible for setting the scans to make sure these are not an attempt to access the system from the outside via the XCOM listener ports.