Distribution List

Enhanced Definition

In the context of IBM z/OS, a Distribution List refers to a predefined group of recipients or destinations used to route output, messages, or data to multiple targets simultaneously. It streamlines the process of delivering information, such as batch reports or system alerts, to a specific set of users, printers, or other systems. In the context of z/OS and mainframe output management, a Distribution List is a predefined group of destinations (e.g., users, departments, printers, or other systems) to which job output, reports, or messages are automatically routed. It simplifies the process of sending the same information to multiple recipients without specifying each destination individually in JCL or application code.

Key Characteristics

- Predefined Grouping: Allows administrators to define a logical group of destinations (e.g., user IDs, printer IDs, JES DESTinations, email addresses) under a single identifier.
- Automated Routing: Facilitates automatic routing of SYSOUT reports, system messages, or application-generated output to all members of the list without individual specification.
- Centralized Management: Often managed through system utilities, output management software (e.g., CA-Deliver, Control-D), or application configurations, providing a single point of control for recipient groups.
- Flexibility: Members of a distribution list can be diverse, including local printers, remote printers, specific user TSO IDs, JES DESTinations, or even external email addresses via a mainframe email gateway.
- Efficiency: Reduces the need to specify individual destinations for each output item, improving operational efficiency and reducing potential errors in report or message delivery.

Use Cases

- Report Distribution: Sending daily, weekly, or monthly batch reports (e.g., financial summaries, audit trails) generated by COBOL or PL/I programs to multiple department heads or specific users.
- System Message Alerts: Routing critical system alerts or operational messages from JES or MVS to a group of on-call system programmers or operators via TSO messages or console alerts.
- Printer Grouping: Directing SYSOUT to a pool of printers, where any available printer in the group can handle the job, ensuring print availability and load balancing.
- Email Notifications: Sending automated email notifications from mainframe applications to a predefined group of business users or support personnel via a mainframe email gateway.
- Data Set Access Notifications: Notifying a group of users when a specific critical data set has been updated or accessed, often through custom REXX or CLIST procedures.

Related Concepts

Distribution Lists are closely related to the Job Entry Subsystem (JES), particularly JES2 and JES3, which manage SYSOUT processing and routing, often leveraging JES DESTinations and USERIDs. They are a core feature of