Previous section.
UMA Data Capture Interface (DCI)
Copyright © 1997 The Open Group
Glossary
API
Application Programming Interface. A standard interface
for program access to a set of services. The DCI API is
defined in this document.
Data Capture Interface
The API for the Data Capture Layer.
Data Capture Layer
The lowest layer in the UMA
metrics architecture.
It is concerned with the collection of raw data from the system.
DCI
Data Capture Interface
DCI server
An abstraction provided by the DCI. The DCI
server provides a set of services to metrics providers and consumers.
DCL
Data Capture Layer
event, event metric
An event is a metric.
An occurrence of some activity of interest
to a metrics consumer (for example, thread
termination).
i18n
abbreviation used in this specification for the term
internationalization
(which has 18 letters between its first and last letters).
metric
A single measurement. Metrics
have unique identifiers defined through
the metrics name space. A metric is either
a polled metric (indicating some statistic
or other data) or it is an event.
Polled metrics have metric values that can
be obtained by querying the DCI.
Events may have associated data returned with
the event when it occurs. (See
Events and Event Data Attributes
).
metric class
Metrics are grouped into metric classes.
Classes are organised in a hierarchy.
A metric class holds no metric values. It
is simply a placeholder in the namespace.
It should be viewed as a template.
metric class instance
Metric values are associated with
instantiations of metric classes. For
example, there could be a class for
per-thread statistics; associated with
this class could be many instances, each
one identified by its thread id. A
particular thread's statistics would
be available by querying the DCI for
that specific metric class instance.
metrics consumer
Any application which needs to import metrics.
metrics provider
Any subsystem which has metrics to export. The
subsystem can either be the operating system or applications.
metric value
The value of a polled metric is referred
to as a metric value. Note that metrics
that are events do not have metric values.
MLI
The Measurement Layer Interface. An upper level service, one of the
possible DCI consumers, that provides a measurement control and data
delivery mechanism.
multiprocessor system
Any machine which contains more than one processor but appears to the
user to be running a single operating system.
octet
An eight bit unit of storage.
operating system
Privileged software which controls hardware resources.
PMWG
Performance Management Working Group. The group which has
specified the Universal Measurement Architecture.
polled metric
A polled metric is a metric. It
typically corresponds to a numerical
count of some system activity, some
statistic, or possibly some configuration
information (for example, the number of processors).
security
That part of an operating system concerned with controlling
access to information.
system space
An address space in which privileged programs, such as
the operating system, are run.
user space
An address space in which unprivileged programs are run. Examples of
such programs are applications or system services which do not require
direct access to hardware resources.
UMA
Universal Measurement Architecture. The collection of the DCI,
Data Pool and MLI that provides a complete performance
measurement
architecture.
Why not acquire a nicely bound hard copy?
Click here to return to the publication details or order a copy
of this publication.