Each view within the WebSphere® Real
Time perspective presents data in specific sections of the display.
The controller window
The controller window
provides the tools for you to select views of WebSphere Real Time data. There are two
main tasks you can perform using the controller window.
- Manage custom views
- You can create a customized view, and add it to the list of available
views. For more information about creating customized views, see Customizing the WebSphere Real Time perspective.
- Select different views
- You can select different views, using a combination box. The box
is populated initially with predefined views. Customized views also
appear in this box if a custom view definition file has
been created and identified in the preferences.
All predefined views
are identified by a System view: prefix. All customized
views are identified by a Custom view: prefix.
The outlier plot window
This window displays
event data as a simple plot graph. The X-axis of the graph shows the
actual time when an event took place. The Y-axis shows the time taken
for the event to occur. For convenience, the Y-axis values can be
adjusted to display using a logarithmic scale.
When you hover
over data in the plot window, a window opens providing details of
the trace point associated with the event.
The histogram window
This window provides
an alternative display of data. It shows a histogram representation
of the data displayed in the outlier plot window. For example, in
the predefined class loading view, the histogram representation shows
how many class loading events took 0 - 1 ms to complete, how many
events took 1 - 2 ms to complete, and so on.
The summary window
This window displays
various statistics, calculated from the data presented in the plot
window. The statistics include:
- Total events processed.
- Maximum time taken.
- Minimum time taken.
- Mean value for time taken.
- Median value for time taken.
- The standard deviation.
Recommendations and analysis window
This
window displays the results of analyzing the collected data. The results
are in the form of a determinism score. If the number of data samples
is too low, the Health Center warns you that the determinism score
might not be accurate. In particular, for Java™ method-based views, where the view descriptor
might match multiple methods, a warning is displayed reporting that
multiple methods have been matched.
The determinism score is
calculated as follows:
- Select all the data points in the plot window.
- Calculate the median data point value - for example, the median
time taken for a class loading event.
- Find how many events fall within the following ranges:
- Median plus or minus 20% of the median value
- Median plus or minus 40% of the median value
- Median plus or minus 60% of the median value
- Median plus or minus 80% of the median value
- Median plus or minus 100% of the median value
- Calculate the average number of events for the ranges.
- The average number is the determinism score, expressed as a percentage.
The determinism score can be interpreted as shown in
Table 1.
Table 1. Interpreting the meaning of a determinism scoreScore |
Meaning |
70 or less |
A very poor result. There is a wide distribution
of results for the event, indicating uneven performance. |
70 - 80 |
A poor result. |
80 - 90 |
A good result. |
90 or more |
A very good result. The results are distributed
closely around the median value, indicating consistent performance. |