Defining the vsam files to cics – IBM Transaction Server OS User Manual

Page 38

Advertising
background image

#transids

is the number of transaction identifiers in the CICS region.

#termids

is the number of terminal identifiers in the CICS region.

Note: The amount of storage needed in the data space for the Builder is about

25% of the storage needed for the Detector.

The algorithm assumes that all affinities are represented, and that all transactions
participate in all affinities, and that all transactions run at all terminals (the worst
possible scenario). This gives a worst case figure.

For example, consider the worst case scenario of a CICS region with 500 different
transaction IDs and 1000 terminals, where all transactions issue all affinity
commands and all transactions run at all terminals.

For this scenario, the storage requirement for the Detector in the data space is:

Data space : 130 Megabytes

CAUAFF1

:

21 Megabytes

CAUAFF2

:

76 Megabytes

CAUAFF3

:

1

Megabyte

The space required for the data space is different than that required for the files
because:

v

each record has a storage overhead in the data space

v

certain tables are not saved to file

v

key length is fixed per file, so short keys must be padded out

Notes:

1. The critical affinity type is temporary storage. The space required for all other

affinity types together should be no more than 5MB.

2. The calculations in this section assume that you do not use unique counters

when naming temporary storage queues. If you do use unique counters, the
space needed for temporary storage affinity types is much greater. For your
calculations with unique counters, replace

#transids * #termids

by the number

of unique queues.

Defining the VSAM files to CICS

The CICS-supplied sample group, DFH$AFFY, contains definitions for:

v

three affinity data files (CAUAFF1, CAUAFF2 and CAUAFF3)

v

the affinity control file, CAUNCNTL

Change some of the attributes of these resource definitions to suit your own
environment. To do this, use the CEDA transaction (or the DFHCSDUP utility) to:

1. COPY the sample group to a group of your own choosing. For example,

CEDA COPY GROUP(DFH$AFFY) TO(mygroup)

2. EXPAND group

mygroup and change the following attributes appropriately:

v

For each resource definition, change the prefixes of the VSAM files, as
defined by the CAUJCLCC and CAUJCLCA jobs.

v

For each resource definition, ensure that the LSRPOOLID specified for each
file is capable of handling the keylength defined for the file. If it isn’t, change
it so that it is. See Table 2 on page 21 for more information.

22

CICS Transaction Affinities Utility Guide

Advertising