HP XP P9000 Performance Advisor Software - Manual (Page 315)

Time Line Chart Style
Time Line chart style (default) enables you to view the plotting of data points for a fixed time interval.
In addition, when data points for multiple metrics are plotted with different collection frequencies,
their relationships with the time intervals are displayed correctly.
Only data points that are collected during the specified interval are retrieved from the database and
plotted on the graph. Data points are not plotted for intervals of time where data collection has failed.
Hence, there can be discontinuity in the graph plotted. In the sense, the graph for that particular
duration displays a blank graph area, indicating a failure in data collection. The data points are
plotted again once data collection resumes.
Moving Average Chart Style
The Moving Average chart style enables you to view the average performance of the selected
components for a specified time interval. The current average (Moving Average) value is calculated
by taking the average of the previous data points. You can specify the number of data points for
which the average needs to be calculated, using the Point Factor list. The minimum that you can select
from the Point Factor list are 2 points and the maximum are 24 points.
IMPORTANT:
•
HP recommends that you select minimum Point Factors for accuracy and better view of the graph
that is plotted.
• Moving Average is calculated as the average of the initial set of data points. Hence, the graph is
not displayed for the initial set of data points. The Point Factor that you select determines the
number of data points that are considered to calculate the Moving Average value.
• Chart displays a break in collection whenever there is a difference in frequency between the current
collection interval and the previous collection interval. For example, you might have set the current
collection interval at five minutes and the previous collection interval at three minutes, resulting in
a change in collection frequency. Thus, the graph displays a break in the plotting of data points,
implies a change in frequency between the previous and the current collection.
The Moving Average values are calculated and plotted only for those data points that are collected
by the data collection process. If the data collection fails, the Moving Average values are not calculated
and plotted on the graph. However, if the collection had not failed, a line displays connecting the
last data point that was plotted before the failure and the first data point that is plotted after the data
collection resumed. As a result, you can view a complete graph for the average performance of the
selected array components irrespective of whether the data collection is active or discontinued. The
legend names for the Moving Average graphs are appended with -MA.
Line Plus Moving Average Chart Style
The Line Plus Moving Average chart style enables you to view the actual performance and the average
performance of the selected components for a specified time interval. Both the Time Line and the
Moving Average chart styles are applied on the performance graphs for the selected components.
Separate Legend items at the right hand corner of the chart window enable you to differentiate a
Time Line graph from a Moving Average graph.
If this chart style is selected along with appropriate point factor, the data points and the average
values are plotted simultaneously when the data collection is in progress. If the data collection fails
for a particular duration, two straight lines are displayed for that duration, indicating a failure in data
collection. The straight line for Time Line connects the last data point that was plotted before the failure
and the first data point that is plotted after the data collection resumed. The straight line for Moving
Average connects the last Moving Average value that was plotted before the failure, and the first
Moving Average value that is plotted after the data collection resumed. This provides you an
approximate idea of the actual and average performance trend if the collection had not failed. Once
HP StorageWorks P9000 Performance Advisor Software User Guide 315