CLAW - Common Link Access to Workstation

Enhanced Definition

CLAW (Common Link Access to Workstation) is a programmatic interface on z/OS that enables workstation applications to communicate with mainframe applications, primarily for event notification and command execution. It provides a standardized way for distributed systems to receive real-time alerts from z/OS and issue commands to the mainframe, often used in automation and monitoring scenarios. CLAW (Common Link Access to Workstation) is a communication protocol that enables a z/OS mainframe application to programmatically interact with an application running on a distributed workstation. It facilitates bidirectional, asynchronous data exchange, primarily used for application-to-application communication.

Key Characteristics

- Programmatic Interface: CLAW offers an API that allows workstation applications to establish a connection and exchange data with z/OS applications, typically automation managers like NetView.
- Event Notification: Its primary use is to push z/OS events (e.g., console messages, system alerts, job status changes) from the mainframe to subscribing workstation applications.
- Command Execution: Workstation applications can use CLAW to send z/OS console commands or commands to specific mainframe applications (like NetView) for execution.
- TCP/IP Based: CLAW communication typically leverages TCP/IP for network connectivity, allowing for flexible integration across various network topologies.
- Asynchronous Communication: It supports asynchronous event delivery, meaning the mainframe can send events without waiting for an immediate response from the workstation, improving efficiency.
- Client-Server Model: The workstation acts as a client, initiating the connection to a CLAW server component running on z/OS (e.g., within NetView).

Use Cases

- Enterprise-wide Monitoring: Integrating z/OS system events and alerts into a centralized enterprise monitoring console or dashboard running on a distributed platform.
- Automated Incident Response: Triggering automated actions on a workstation (e.g., opening a ticket, sending an email/SMS) in response to specific mainframe events like critical errors or resource thresholds being exceeded.
- Remote Command Execution: Allowing authorized workstation applications to issue z/OS console commands or NetView commands to manage mainframe resources or troubleshoot issues remotely.
- Batch Job Status Reporting: Notifying distributed applications or users about the completion, success, or failure of critical JCL batch jobs.
- Integration with DevOps Toolchains: Providing a mechanism for modern DevOps tools running on distributed platforms to interact with and receive feedback from mainframe build and deployment processes.

Related Concepts

CLAW is often tightly integrated with IBM NetView, which typically acts as the CLAW server on the z/OS side, processing events and executing commands. It relies on TCP/IP for network communication, making it a key component in bridging traditional mainframe operations with modern IP -based distributed systems management. CLAW complements other z/OS automation capabilities by extending their reach to non-mainframe platforms, allowing for a unified view and control across the enterprise. It provides a more programmatic and real-time alternative to polling mainframe logs or using file -based data exchange for event notification.

Best Practices:

Secure Connections: Always configure CLAW connections to use TLS/SSL encryption to protect sensitive event data and command traffic from eavesdropping and tampering.
Least Privilege: Implement robust authorization mechanisms on z/OS to ensure that only authorized workstation applications can connect and execute specific commands via CLAW.
Event Filtering: Configure the mainframe CLAW server (e.g., NetView) to send only relevant events to workstations, reducing network traffic and processing overhead on both ends.
Robust Client Logic: Design workstation applications with comprehensive error handling, retry logic, and connection management to gracefully handle network interruptions or mainframe outages.
Monitoring and Alerting: Monitor the health and activity of CLAW connections on z/OS, including resource consumption and connection status, to proactively identify and address potential issues.