File analysis

VSAM files are key resources to CICS® applications. A typical CICS application accepts a request from a terminal-user, searches through or updates files, and sends the results back to the terminal. File access is often the largest component of CICS response time and therefore should be monitored and well-tuned.

In addition to application files, CICS dumps, traces, transient data, and auxiliary temporary storage all reside in VSAM data sets. A VSAM data set experiencing string or buffer waits, or excessive CI or CA splits, can adversely affect CICS performance.

CICS dump and trace data sets also need to be monitored in case they are filling up too fast. Insufficient library space or improper load library concatenations for STEPLIB or DFHRPL can also cause CICS problems.