Defining and maintaining group definitions - IBM - AS/400

You cannot create resource definitions until you have created the resource definition groups. When you create a group, a file is created for each type of table. You do not need to supply resource definitions for each table. In particular, the SIT and GLT might not contain entries.

What is a resource definition group?
A resource definition group defines a set of related resources. All table entries must be in a group. For example, resources may be grouped by application set or by business department. Other groups may include a set of common resources such as system definitions. This provides a way of selectively including resource definitions at control region startup. Predefined groups are provided for CICS-supplied transactions.

When a group is created, all resource definition tables, including a SIT and GLT, are created for that group. However, you do not have to provide entries for all tables. In particular, you may not want a SIT or GLT for all groups.

It is possible to assign a resource to more than one group. This means that different sets of resources can be specified for different situations. Thus resources with the same entry name but different group name may have differing data associated with them.

Using the resource definition CL commands
There are five CL commands used to create and maintain CICS groups:

  1. CRTCICSGRP:Create a new group or recover a damaged group. A group must be created before you can add resource definitions to it.When you create a group, one of two things happens:
    • If there are no other CICS groups in the specified target library, new physical files (for example AAEGDADCP) and logical files(for example, AAEGDADCL) will be created in the new library. All possible physical and logical files are created in the library even if you have no intention of adding resources of all types to the CICS group.
    • Alternatively, if a CICS group already exists in the target library, a new member is added to all the physical and logical files.
  2. CHGCICSGRP: Use the CHGCICSGRP command to modify the descriptive text.
  3. DLTCICSGRP: Use the DLTCICSGRP command to remove all objects associated with a specific group.
  4. SAVCICSGRP: Use the SAVCICSGRP command to save groups for use on either the current or previous release of CICS/400. SAVCICSGRP converts resource-definition tables for use onthe previous release if necessary.This command calls the OS/400 SAVOBJ system command.
  5. WRKCICSGRP: Use the WRKCICSGRP command to list a selection of groups and perform various operations on them. You can work with one or several groups at a time. The groups are selected according to criteria entered in the command. You can use either of the following methods:
    • Enter the WRKCICSGRP command with selection criteria. You can change, delete, or work with any of the groups, or you can add new group definitions.
    • Use the CEDA transaction.

Specifying which groups are used
The SITLIB and SITGRP parameters of the STRCICS (start a CICS/400 control region) command used to specify the SIT to be used for the control region. The GLTLIB and GLTGRP parameters of the SIT specifies which GLT is to be used to load resource definitions. The INSLIB and INSGRP parameters of the Group list Table (GLT) entries define which resource groups are to be installed, and in which order, for that control region. The groups are installed in the order in which the GLT entries were created.If there are duplicate definitions, the entries in the later groups overwrite those already installed. If any of the groups named in the GLT include a GLT or SIT, these are ignored. Only the SIT named in the STRCICS command and the GLT named in that SIT are used in the control region.

The group containing the GLT may include other resource definition tables. If this is the case, the GLT group name must be included as an entry in the GLT. Otherwise the resource definitions will not be installed when the control region is started.

For example, the command:

STRCICS CTLRGN(TEST) SITLIB(JOHN) SITGRP(ALAN)

will start control region TEST using the SIT in group ALAN in library JOHN. The SIT contains the parameters GLTGRP(FRED) and GLTLIB(JOHN). CICS/400 uses the SIT in group ALAN to start up the control region and the GLT in group FRED to load resource definitions. The GLT contains the following group definitions:

ADDCICSGLT LIB(JOHN) GROUP(FRED) INSLIB(JOHN) INSGRP(ALAN)
ADDCICSGLT LIB(JOHN) GROUP(FRED) INSLIB(JOHN) INSGRP(FRED)

When control region TEST starts, the GLT specified in the SIT, namely that in group FRED in library JOHN, is used to determine which resource definitions are installed. Groups ALAN and FRED are installed, with group ALAN being installed first. Any definitions in group FRED that duplicate those in group ALAN overwrite those installed from group ALAN. If the GLT entry for group FRED had been omitted from the GLT, no resources in that group would have been installed, but the GLT in group FRED would still have been used to control which resources were installed.

Recovering groups
Use theRecoveroption of theWork with CICS Grouppanel. The action taken depends upon two parameters of the CRTCICSGRP command:

  1. The RECOVER(*YES) parameter specifies that CICS/400 is to re-build the complete set of OS/400 members required for a specific group.

    Note:This does not recover the records in the OS/400 members; it only makes sure that all the OS/400 members for the specified group exist.

  2. The CLRGROUP parameter is valid only if RECOVER(*YES) is specified. This parameter checks that all OS/400 members for the specified group exist and removes any entries that you had made for that group. The group is left in the state that it was when first created; that is, with no entries.

    Attention:Be careful how and when you use the CLRGROUP parameter. This parameter deletes all definitions in all table types for this group.


All rights reserved © 2018 Wisdom IT Services India Pvt. Ltd DMCA.com Protection Status

IBM - AS/400 Topics