Broadcast

Enhanced Definition

In the context of z/OS, "broadcast" primarily refers to the capability of sending messages or notifications to multiple users, terminals, or system components simultaneously. It is commonly used for system-wide announcements, operational alerts, or user-specific communications within the TSO/ISPF environment.

Key Characteristics

- System-wide Reach: Messages can be directed to all active users on the system or specific groups/individuals logged into TSO/ISPF.
- Asynchronous Delivery: Messages are typically delivered to users as they log on, or are displayed on their screens without requiring an immediate response from the sender.
- TSO/ISPF Integration: For TSO users, broadcast messages are stored in a dedicated BROADCAST dataset (e.g., SYS1.BRODCAST) and displayed upon login or via the BROADCAST command.
- Operator Initiated: System operators frequently use commands like SEND to broadcast messages to users or consoles.
- Automated Capabilities: Automated operations tools can trigger broadcast messages based on predefined system events or thresholds.
- Informational or Action-Oriented: Messages can convey information (e.g., system status) or request user action (e.g., log off for maintenance).

Use Cases

- System Maintenance Announcements: Notifying all logged-on TSO users about an impending system shutdown, IPL, or scheduled maintenance window.
- Critical System Alerts: Broadcasting urgent messages regarding system performance degradation, resource contention, or security incidents to relevant personnel.
- User-Specific Communication: Sending a message to a particular user ID about a job completion, dataset availability, or an issue requiring their attention using the SEND command.
- Operator Instructions: Operators using broadcast facilities to instruct users to save work or log off before a critical system change.
- Automated Notifications: An automated operations product sending a broadcast message to an on-call administrator's TSO session when a critical subsystem fails.

Related Concepts

Broadcast functionality is tightly integrated with TSO/ISPF, serving as the primary mechanism for user communication within that interactive environment. It complements Operator Commands (e.g., SEND) by providing a user-facing delivery channel for system messages. While distinct from general System Messages (WTO/WTOR), which are primarily for operator consoles and log files, broadcast messages often originate from events that also generate WTOs. Automated Operations solutions leverage broadcast capabilities to deliver proactive or reactive alerts to human operators or users.

Best Practices:

Conciseness and Clarity: Keep broadcast messages brief, clear, and to the point, stating the purpose, impact, and required action (if any).
Timeliness: Send critical broadcasts with sufficient lead time for users to react, especially for disruptive events like shutdowns.
Targeted Delivery: Use options to