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HyperSpi provides graphical representations of selected VMS systems'
performance indicators. These indicators can be used to help assess the
overall performance of a system, or to assist in the identification of
probable factors in instances of observed poor performance. For guidelines on
interpreting VMS systems performance data see
Performance Assessment Guidelines.
This facility has been provided primarily for those involved in VMS
systems management, but is also available for the general user to gain some
appreciation of what a particular system is doing at any particular stage of
the day or week. (It has not been provided to facilitate the creation of
a dozen systems performance experts :^) )
How It Works
The facility comprises two distinct components:
- The data gathering application. This permanently executes on
selected systems. It obtains specific data from the VMS System Performance
Interface once a second. This is accumulated for a period of one minute
before being output as peaks and averages to on-disk storage. The one second
collection period provides excellent granularity for observing peak
behaviours, while the one minute recording period provides sufficient
granularity for meaningful observation of short-duration trends (within an
hour) as well as long-term behaviours (days or weeks), all without consuming
significant amounts of mass-storage. The data gathering utility has minimal
impact on the system it is recording, less than one-tenth of one percent of
one CPU, measured on AXP systems.
- The data processing/presentation application. This is designed to
use the hypertext-interface of a browser such as Mosaic, employing the
forms HTML facility to provide a versatile and easy-to-use interface for
selection of the data to be presented, as well as the browser's image display
capabilities, to present graphs of performance data integrated with textual
information. Data is processed on-demand, meaning graphs are generated
dynamically, allowing simple, rapid assessments of current and recent
performance, as well as longer-term overviews in versatile combinations of
periods and factors.
Selection Of Data
A menu of options is presented allowing selection by radio-button
(one of multiple), checkbox (one or more of multiple), and direct
textual input.
- System
A series of radio-buttons allows selection of the system to be
processed.
- Period
A series of radio-buttons allows selection of one of a number of
standard periods for processing and display of the data. From 7am up to and
including the current hour of the day is selected by default. Alternatively,
the starting and ending time and date may be explicitly specified.
- Category
A series of checkboxes allow selection of one or more data
categories for processing and display. A combination useful for basic
assessment is selected by default. These may be deselected, others added, and
so forth. More than four categories tends to become cluttered.
When ready, click on the process button to process and present the
selected data. The double-height graph checkbox allows graphs to be
generated with an X axis twice the normal size. This can be useful when
examining a specific category in greater detail, but can make a multi-category
display more difficult to overview. The reset button returns all
selectors to default.
A slightly more
comprehensive menu
is available.
Presentation Of Data
The data selected by category and period is presented as a single page of
text and graphic. The page is titled with the system name, the period the
data represents, and a short description of the system (number of CPUs,
memory, etc.).
Graphs are simple two-dimensional representations providing time along the
X axis (graduated in hours and days), and quantity along the Y axis (either as
a percentage of total available or as an absolute quantity). A short
description of the graph and applicable scales, averages and maxima are
provided following the graph. Graphs may contain one or two quantities,
presented as a filled histogram, and/or as plotted points. The following
example illustrates each component:
- X Axis ... the period, graduated in hours and days (if applicable)
- Y Axis ... the quantity, appropriately graduated
- Data Available ... a horizontal line below the X axis indicating
data was available for that sample time (gaps in data can thus be
discriminated from zero quantities, as illustrated by the gap near 3a)
- Current Time ... a small vertical bar at the end of the data
available indicator (if current time falls within the specified period)
- Histogram ... each datum is represented by a bar
- Plotted ... each datum is represented by a plot point (these may
or may not form a (semi-)continuous line, depending on the data characterstics,
here scattered due to a highly variable quantity)