Discovery
In the mainframe and z/OS context, **Discovery** refers to the process of identifying and cataloging available system resources, configurations, and dependencies. This includes locating data sets, programs, network services, system metrics, and active processes, often for purposes of inventory, troubleshooting, or automation. In the mainframe and z/OS context, **Discovery** refers to the process of identifying, locating, and cataloging various system resources, components, configurations, and dependencies across the enterprise computing environment. This includes anything from datasets, programs, and started tasks to network connections, middleware subsystems (like CICS, IMS, DB2), and hardware elements. Its primary purpose is to gain an accurate and up-to-date understanding of the operational landscape.
Key Characteristics
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- Resource Identification: Focuses on pinpointing the existence and attributes of various mainframe resources, such as
data sets,volumes,libraries,programs,transactions,started tasks,network connections, andsystem parameters. - Tool-Driven: Often performed using specialized z/OS utilities and commands like
ISPF(for data sets and members),SDSF(for jobs, tasks, and system logs),TSO/Ecommands,REXXscripts, or third-party monitoring and automation tools. - Dynamic vs. Static: Can involve dynamic real-time querying of active system components (e.g., active
CICSregions,DB2subsystems) or static analysis of configuration files and catalogs (e.g.,SYSRESlibraries,VTAMdefinitions). - Scope: Discovery can range from a narrow search for a specific program or file to a broad scan of an entire LPAR or sysplex for all active services, network endpoints, or resource consumption patterns.
- Metadata Collection: Beyond just identifying resources, discovery often involves collecting associated metadata, such as creation dates, last access times, sizes, security profiles, and dependencies.
- Resource Identification: Focuses on pinpointing the existence and attributes of various mainframe resources, such as
Use Cases
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- Troubleshooting and Problem Determination: Quickly locating log files, specific program modules, or active processes that are causing issues, or identifying the status of network connections.
- System Inventory and Auditing: Building and maintaining an accurate inventory of all installed software, data sets, and system configurations for compliance, capacity planning, and asset management.
- Application Modernization and Migration: Identifying all components, dependencies, and data sources for existing mainframe applications to facilitate refactoring, re-platforming, or integration with distributed systems.
- Security Analysis: Discovering open ports, unauthorized data sets, or misconfigured security settings (
RACFprofiles) that could pose vulnerabilities. - Automation and Orchestration: Providing real-time resource availability and status information to automation scripts or workload managers to optimize resource allocation and job scheduling.
Related Concepts
Discovery is fundamental to many z/OS operations. It heavily relies on system services like the Catalog for data set location, VTAM for network resource information, and SMF (System Management Facilities) for collecting system activity data that can be analyzed for resource usage patterns. Tools like ISPF and SDSF are primary interfaces for manual discovery, while REXX and JCL can automate discovery tasks. Effective discovery also informs Workload Management (WLM) by providing insights into resource consumption and helps validate RACF security profiles by revealing accessible resources.