IBM OS manual Controlling the Detector, How the affinity data is collected

v Command is a non-terminal-related START or a DPL

v ENQ or DEQ commands that specify a resource name for which an appropriate

ENQMODEL de®nition is enabled, and that ENQMODEL has a nonÐblank

ENQSCOPE

The Detector does not detect CICS macro-level commands, MVS POST calls, or

the hand posting of ECBs.

If you continue a pseudoconversation by setting a transid in the TIOA (rather than

by using RETURN TRANSID), the Detector cannot detect PCONV lifetimes. In this

case, the shortest lifetime detected is LOGON or SIGNON because it interprets

every transaction end as a pseudoconversation end.

Ideally the Transaction Affinities Utility should ignore commands issued by

task-related user exits and global user exits because they are not part of

applications. However, it cannot distinguish such commands from others, and does

detect them. If your user exits use commands that can cause transaction affinities,

the commands are detected, perhaps making any affinity problem seem worse than

it actually is.

If an exit program at XICEREQ or XTSEREQ modi®es the EXEC CICS command,

that modi®cation is not visible to the Detector. (It detects the original, unmodi®ed

command.) However, if an XICEREQ, XICEREQC, XEIIN, XTSEREQ, or

XTSEREQC exit program (or an XEIOUT exit program invoked earlier) modi®es

EIBRESP, the Detector sees the modi®ed value.

Controlling the Detector

You can monitor and control the Detector through the CAFF transaction, which

enables you to start, pause, continue, and stop the collection of affinity data into the

tables in the data space. Using the CAFF transaction, you can also specify for

which affinity commands, and for which transactions, data is to be collected.

The options that you specify to control the Detector for a CICS region are preserved

in a recoverable VSAM control ®le. For more information about this ®le, see ªThe

control record VSAM ®leº on page 17.

How the affinity data is collected

The Detector uses a number of affinity tables in the data space to hold collected affinity data. The affinity tables are in three categories:

1.There is an affinity table, or set of tables, for each of the following command groups that cause inter-transaction affinity:

v ENQ and DEQ commands

vREADQ TS, WRITEQ TS, and DELETEQ TS commands

vLOAD HOLD and RELEASE commands

vRETRIEVE WAIT and START commands

vADDRESS CWA commands

vGETMAIN SHARED and FREEMAIN commands

vLOAD and FREEMAIN commands

vCANCEL, DELAY, POST, and START commands

The tables for a particular group have a structure appropriate to that group.

Chapter 2. Introducing the Transaction Affinities Utility 15