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UMA Data Pool Definition (DPD)
Copyright © 1997 The Open Group



This document is one of a family of documents that comprise the Universal Measurement Architecture (UMA), and which define interfaces and data formats for Performance Measurement. UMA was originally defined by the Performance Management Working Group (PMWG) and subsequently adopted by The Open Group.

This document defines a performance data pool for the analysis and management of computer systems, and an organisation to facilitate the collection and use of such data.

The UMA is defined in the following documents:


The metrics defined in this document span a wide range of uses. The audience for these metrics ranges from the end-user to the system developer:


The metrics defined in this document attempt to meet the data use needs for the various audiences mentioned above. Although the metrics are heavily influenced by the currently available measurements, an attempt is made to recommend new metrics to correct the deficiencies experienced with existing technology. Metrics are grouped into "Classes" amd "Subclasses" based on their functionality and content. Furthermore, to reflect the current technology and to accommodate for future growth, each metric is assigned a "Level" of maturity. Specifically, each metric belongs to one of the following four categories:

The first three categories are part of the Datapool Standard. The level 0 specification is an attempt to formalize existing common practice, and should be implementable on the bulk of the UNIX installed base, using OS releases that were available in 1995. The Level 1 specification is to provide direction for OS vendors, and defines a common set of metrics that are needed to implement performance management tools. Additional details on the levels are found in Chapter 2.

This document defines no interfaces or other architecture, only data and a data organisation.

Performance and capacity management of operating systems have been considered "internal" to the operating system and as such differ from one operating system to another and from one implementation to another. Most operating systems have, as a matter of necessity, performance analysis modules, narrowly targeted at the type of hardware, software and networking facilities implemented within the system.

Most operating systems provide ad-hoc developed or tailored performance metrics. Some of these tools are developed as internal support tools for benchmarking or on demand from performance analysts and capacity planners. These tools are generally also confined to one machine only and can not be interrogated remotely.

The new era of networking and interoperability views performance management and capacity planning from user's perspective. Multiple machines and operating systems can be involved in the interaction with the user. This approach requires capture and presentation of performance metrics to be clearly defined and portable between platforms and operating systems.

In addition, the data used in this specification is presented as vendor and implementation independent as possible, however, a mechanism is provided for vendor data extensions.


Support for Datapool level 0 is mandatory, while support for higher levels is optional.

Conformance to levels higher than zero means that metrics defined as mandatory in such levels must all be provided.

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