CICSPlex SM API programs that use the CONNECT verb specifying a VERSION keyword for a previous release of CICSPlex SM can experience significant increases in both CPU consumption by the CMAS address space, and data space storage utilization by the Environment Services System Services (ESSS) address space.
API programs that specify a CRITERIA string to limit the size of a result set on a GET or PERFORM OBJECT request, or use the SPECIFY FILTER verb, can experience the increase in CMAS CPU and ESSS storage. Batch job runtimes might also increase.
You are not required to recompile your CICSPlex SM API programs when you migrate releases. However, if you do not recompile affected programs, the CMAS has to convert the records from the current release format, to the level specified on the VERSION keyword on the CONNECT verb. This transformation process is highly intensive for CPU and storage when the result set is very large, for example, 300K to 500K records. The increases are observed in most cases when a criteria string is used to filter the result set; for example, specifying a criteria for the PROGRAM object using the NAME key for a specific or generic program. In this scenario, CICSPlex SM has to retrieve all program objects and return them to the CMAS where the API is connected, transform the records to the version of the API, and then apply the filtering.
If you recompile your programs to specify the VERSION keyword to match the current release of CICSPlex SM, this conversion does not take place, and there is no significant increase in storage or CPU consumption.