IAM/RLS Implementation

This section provides the outline of the procedure to follow to activate and implement IAM/RLS. We recommend that you start with a very limited implementation, and then as you grow comfortable with IAM/RLS, the use of it can be expanded to more data sets. Many of the parameters that control IAM/RLS can be easily modified while IAM/RLS is active, which will minimize the need to deactivate IAM/RLS to broaden the implementation to more data sets. Within any CICS region or batch job, there can be some IAMdata sets using IAM/RLS, while other  IAM data sets are not using the IAM/RLS services.

Careful planning and consideration must be given to how to recover data when a software or hardware error occurs. This is particularly true if you’ve never used any type of data sharing software in the past. For example, if a batch job abends, you may not be able to just restore a data set and restart the job because of the potential loss of data from CICS users concurrently updating the data set. IAM does provide journaling and recovery capabilities that can be used to perform various types of recoveries. You should determine ahead of time what your needs are, which can be different for your different data sets and applications. Careful planning and testing of recovery procedures will be of great benefit to successfully implementing IAM/RLS.

The various tasks necessary to implement IAM/RLS are shown below. Please be sure to review all of the sections to make sure that nothing is missed as you develop your implementation plan.

• Set up the IAM/RLS proc within the appropriate system proclibs, and allocate any required parameter libraries. For the details on the IAM/RLS proc and address space requirements, see IAM-PLEX-implementation. A separate proc will need to be created for each IAM/RLS address space that is to be executed.
• Define a Record Lock Recovery data set for each IAM/RLS address space that will need persistent lock support. For the details on performing this setup, see Setting-up-IAM-RLS-Record-Level-Sharing.
• Review and select the appropriate values for the various IAM/RLS parameters. For detailed information on the IAM/RLS parameters, see IAM-RLS-parameters .
• Set up the appropriate criteria for your installation for the IAM/RLS automatic data set selection. For the details on automatic data set selection, see IAM-RLS-Automatic-Data-Set-Eligibility .
• Allocate the IAM/RLS log data sets required to support the journaling that you need IAM/RLS to perform. Set up the procedures to offload the log data sets, and retain the data for subsequent recoveries as might be needed. For information on IAM/RLS Journaling. Unique sets of journals will need to be allocated for each separate IAM/RLS address space that is to be used, see IAM-RLS-Journaling .
• Review IAM-RLS-CICS-Considerations on CICS Transaction Server considerations. Install and activate the necessary CICS exits provided by IAM in every region that will be using IAM/RLS. The CICS exits are critical for IAM to perform record locking for CICS. Failure to properly install and implement them will result in record lockouts and other failures. There are no application or JCL changes required for CICS to use IAM/RLS.
• Review IAM-RLS-Batch-Considerations on batch application considerations. For batch jobs that update a large portion of the records in any recoverable file that is processed by IAM/RLS, seriously consider using the IAM/RLS Batch Syncpoint program, along with providing recovery and restart, should such programs experience software or hardware failures.
• Plan and develop procedures for data recovery, to be prepared in case of unexpected software or hardware errors occur. Make sure that your implementation for IAM/RLS journaling will provide the necessary data to perform data recoveries that will be necessary when failures occur. For information on recovery of data for IAM files being processed under IAM/RLS, see IAM-RLS-Data-Recovery.
• Review IAM-RLS-operator-commands on the IAM/RLS operator commands, for information on the various operational requests that can be made of IAM/RLS.
• Update the IAM Global Options RLS and RLSID as appropriate. The RLS Global option specifies what technique will be used for IAM/RLS data set selection and RLSID supplies the default RLSID for this z/OS image. The default RLS value is NONE and it is highly likely that you will wish to change this option to a different value such as RLS=(TABLE,OPTIONAL). For more information, see IAM/RLS Operator Commands.