There are several configuration changes you can make to z/OS system components that might improve WebSphere Application Server performance on the z/OS platform.
You might want to make one or more of the following changes to the indicated z/OS components:
D TRACE,COMP=ALLTo change the setting for an individual component to its minimum tracing value, use the following command, where xxx is the component ID.
TRACE CT,OFF,COMP=xxxThis configuration change eliminates the unnecessary overhead of collecting trace information that is not needed. Often during debug, CTRACE is turned on for a component and not shut off when the problem is resolved.
Ensure that you are not collecting more SMF data than you need. Review the SMFPRMxx settings to ensure that only the minimum number of records are collected.
SMF Type 92 records are created each time an HFS file is opened, closed, deleted, and so forth. Almost every web server request references HFS files, so thousands of SMF Type 92 records are created. Unless you specifically need this information, turn off SMF Type 92 records. In the following example, we have disabled the collection of SMF type 92 records:
ACTIVE, DSNAME(SYS1.&.SYSNAME..SMF.MAN1;SYS1.&SYSNAME..SMF.MAN2;), NOPROMPT, REC(PERM), MAXDORM(3000), STATUS(010000), JWT(0510), SID(&SYSNAME;(1:4)), LISTDSN, SYS(NOTYPE(19,40,92)), INTVAL(30), SYNCVAL(00), SYS(DETAIL,INTERVAL(SMF,SYNC)), SYS(EXITS(IEFACTRT,IEFUJI,IEFU29,IEFU83,IEFU84,IEFU85,IEFUJV,IEFUSI))
You might find that running with SMF 120 records in production is appropriate, since these records give information specific to WebSphere applications such as response time for J2EE artifacts, bytes transferred, and so forth. If you do choose to run with SMF 120 records enabled, we recommend that you use server interval SMF records and container interval SMF records rather than server activity records and container activity records.