All software products use a common rules language for product customization. Each product typically has one or more rules members found in the PDS allocated to the PARMLIB DD statement in the DIF started task. By default, the data set name used throughout the documentation is DTS.R71.RULELIB. The default rule names follow:
PTLRULES Default rule name for SIMULATE 2000 ACCRULES Default rule name for ACC and SRS DSLRULES Default rule name for DLimit MONPOOLS Default rule name for Monitor
RTMRULES Default rule name for SCC Monitor/Realtime ABCRULES Default rule name for Application Backup Center SMSDEBUG Default rule name for SMS/Debug
The rules members contain the installation dependent setup options found on the DEFPROD control statement, and control logic defined by DEFRULE statements. The DEFRULE statements use IF-THEN-ELSE logic to control the product functions. These functions are usually executed by other rule statements. Messages, log records and SMF records are defined by DEFMSG, DEFREC and DEFSMF statements.
Rules are Compiled into Extended CSA
When a product is started by the Dynamic Install Facility (DIF started task), or a DIF REFRESH console command requested, the control cards for the rules are converted into data structures and placed in extended CSA. The compiled rules allow the products to scan the rules very quickly, and keep product overhead to a minimum.
Messages, Log Records, SMF Records, and Operator Commands
The rules language has facilities to produce messages, log records, SMF records, and operator commands. For example, when a TSO user attempts to allocate a data set to an improper volume, an ACC rule can be used to correct the request, and write a message explaining why the correction was made. Messages can be delivered in many ways. By default, batch jobs and started tasks receive messages via the JES message log, and TSO users receive messages by way of the TPUT SVC.
To monitor events that occur, the products allows copies of a message to be written to data sets, or sent to a specified TSO userid. To establish a more permanent audit trail, a rule can produce a log data set or SMF record for later examination.
Messages, log records, SMF records, and operator commands can be built using literal character strings and symbolic fields. The symbolic fields are substituted into the fixed text before issuing a command, or writing a message, log record or SMF record.
Tracing Facilities
When developing a rule it is often useful to examine the information used in the decision process. The rules tracing facility can be enabled with the use of special DD statements depending on the product: PTLTRACE, ACCTRACE, MONTRACE, DSLTRACE, EXTTRACE and SMSTRACE. This facility allows the person working on the rules language to view all the compare operations that occur during rule processing. For more information, examine the “TESTING AND DEBUGGING” chapter in the appropriate product manual.