Autoinstall Processing Of Mapsets; System Autoinstall; Benefits Of Autoinstalling Programs; Reduced System Administration Costs - IBM SC34-6814-04 Customization Manual

Autoinstall processing of mapsets

Table 30 shows the differences in mapset processing between CICS regions with
program autoinstall active and inactive.

System autoinstall

Some programs are autoinstalled automatically (if they have not been statically
defined) by the CICS system autoinstall function, which does not require model
definitions or the support of the autoinstall control program. Programs in this
category include:
v First phase program list table post initialization (PLTPI) programs (that is, PLTPI
v Second phase program list table shutdown (PLTSD) programs (that is, PLTSD
Note: PLTPI programs that are defined after DFHDELIM, and PLTSD programs

Benefits of autoinstalling programs

Program autoinstall reduces system administration, virtual storage usage, and,
potentially, restart times.

Reduced system administration costs

Without autoinstall, you have to define all new programs, mapsets, and partitionsets
to CICS before they can be used. Autoinstall eliminates this requirement, enabling
these resources to be used without prior definition. Furthermore, the need to
maintain predefined definitions also disappears, leading to a significant saving in
system administration effort.

Saving in virtual storage

There is a saving in virtual storage within the CICS address space, as the
definitions of autoinstalled resources do not occupy table space until they are
generated.
Note: This assumes that the autoinstall control program chooses not to
install a definition. If no definition is installed because autoinstall
fails, the dynamic routing program is not invoked.
Table 30. Differences in mapset processing between autoinstall and non-autoinstall
Program autoinstall INACTIVE
CSD definition is required. CICS attempts to
load a referenced mapset with a suffix. If this
fails, CICS tries an unsuffixed version. If that
is unsuccessful, abend APCT is issued.
programs that are defined before the PLT table delimiter DFHDELIM).
programs that are defined after the PLT table delimiter DFHDELIM).
that are defined before DFHDELIM, are treated like any other user
programs—they are eligible for program autoinstall.
Program autoinstall ACTIVE
CSD definition is not required. Using
autoinstall, CICS attempts to load the
referenced suffixed mapset or partitionset,
then the unsuffixed one. (In each case, a
definition is autoinstalled.) The transaction
requesting the resource abends only if no
version of the resource exists in the library,
either suffixed or unsuffixed.
If the suffixed mapset was not found in the
library, the definition is marked 'not loadable'.
Chapter 16. Writing a program to control autoinstall of programs
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