We have been engaged for a system contention issue in which XCOM was involved. We looked for the file in contention in the XCOM task log, but there was no reference there. Via the XCOM panels we didn't see any active, hold or aborted transfers related to the file.
After reviewing the XCOM STC log the following messages were found:
XCOMM0204E *TCP/IP* RC 08 5C ON PUT RRDS VSAM SLOT 00000003
XCOMM0455E XCOMAPPL HAS ENCOUNTERED A CRITICAL ERROR ON DATASET XCOMRRD
The 08/5C indicates that a GET for UPDATE didn’t complete successfully before the PUT for UPDATE. What we have seen in the past is a problem where a VSAM BUFFER wasn’t available at the time of the GET request.
It was also noticed that LSR is being used for the XCOMRRDS file and that a IBM product called Star Tool is being used to provide LSR support for that same XCOMRRDS. If you want to use LSR, it is strongly suggested that you use the JCL LSR method that we provide in our sample JCL members. The XCOMRRDS needs to be excluded from processing by Star Tool.