Running multiple TOMs within a sysplex

During AutoCustomization you must allocate a registry data set for the TOMPLEX. The data is maintained in the TOM registry data set, which is specified by the REGISTRY_DSN parameter in BBPARM member MAMPLXxx. There is one registry data set per TOMPLEX. You can also allocate the registry data set manually by modifying and submitting the TOMALLOC sample JCL in the UBBSAMP or BBSAMP library. For more information about the registry, see Overview of the registry.

All of the TOM PASs in a TOMPLEX share the same registry data set. The first TOM PAS to initialize in a TOMPLEX becomes the owner PAS of this RTCS SYSPLEX shared registry; this PAS is considered the registry owner. As other TOM PASs initialize in the TOMPLEX, they are considered remote user PASs and forward their registry requests to the owner PAS through XCF communications facilities. If the owner PAS becomes unavailable, one of the other PASs in the TOMPLEX takes ownership of the registry. This transition occurs automatically.

This process allows each TOM PAS to effectively monitor and manage the defined objects on each LPAR. Any changes in an object’s status or definition are available automatically to the other TOM PASs in the TOMPLEX.

As an example, suppose you have six LPARs in a sysplex. Each LPAR has one TOM PAS to manage its objects. Three of the LPARs perform production processing. Two LPARs are allocated for testing applications. The last LPAR is used for development work. You want to keep the administration, monitoring, and management of the three groups separate.

To separate the TOM PASs

1. Edit the TOMPLEX keyword in BBPARM member MAMPLX00
2. Specify a one- to eight-character alphanumeric value that is unique for this TOMPLEX.

   The TOM PASs that use this parameter member are in the same TOMPLEX and share the same registry data set.

   The following example shows sample contents of the BBPARM member MAMPLX00 and how to specify a new TOMPLEX name called PROD:

   * Parameter=Default              Values       Description                       
   * ------------------             ------       --------------------------------- 
   *                                                                               
   * TOMPLEX=BMCTOM                 8-char       TOMPLEX name                      
   *                                                                               
   *                                                                               
   * TOM_XCF_GROUP=BMCTOMX          8-char       XCF group name to use for         
   *                                               intra-TOM communication.        
   *                                                                               
   *                                               This must be different from     
   *                                               the TOMPLEX specification.      
   *                                                                               
   *                                                                               
   * REGISTRY_DSN=                  44-char-     Dataset name of the               
   *                                DSN            Registry VSAM Linear            
   *                                               Data Set (VLDS).                
   TOMPLEX=PROD
   TOM_XCF_GROUP=TOMPRODX
   REGISTRY_DSN=PROD.TOM.REGISTRY

   The MAMPLX00 member can be shared among the three TOM PASs that are managing the production resources. This member is stored in a data set that is associated with the BBIPARM DD in the TOM PAS.

3. Save the member with a suffix of PR (for production): MAMPLXPR.
4. Create UBBPARM member MAMPLXTE (for test) with TOMPLEX=TEST.
5. Create UBBPARM member MAMPLXDE (for development) with TOMPLEX=DEV.
6. Create members MAMCFGPR, MAMCFGTE, and MAMCFGDE to point to the respective MAMPLXxx members.
7. When starting the production PAS, use the CFG=PR parameter on the START command.

   START MVTOM,CFG=PR

   This parameter allows one UBBPARM data set to be shared by all TOM PASs. Alternatively, each TOM PAS could have the BBIPARM DD point to its own UBBPARM data set, which would eliminate the need to start the TOM PAS with the CFG parameter.

   CFG=00 is the default, so if you do not specify anything, the parameter member name must have a suffix of 00 (for example MAMPLX00). See Multiple TOM PASs: BBPARM member MAMCFGxx for more information.