Scenario 1: Viewing current system health

The following scenario shows how to collect and display snapshots and helps you understand the chart and the values displayed. As an example, it uses the data view that you previously created.
Perform the following steps:
  1. To start the collection and display of snapshots, in the toolbar, select Automatic in the Refresh field.
  2. To specify how often a snapshot is to be collected and shown in the data view: click in the time field next to the Refresh field and overtype the displayed time with 0:00:06, which is 6 seconds. Then press Enter.

    The data in the data view is refreshed every 6 seconds, which is the minimum refresh time.

    By default, the latest eight snapshots are displayed in a bar chart. When this number is exceeded, a scroll bar appears at the bottom of the chart for you to scroll through the snapshots collected since the start of the collection. By default, up to 100 snapshots are kept in memory and can be viewed. Any older snapshots are stored in the history data set and can be viewed in history mode. See Scenario 2: Viewing past system health.

    The background color of a snapshot alternates for you to see when a new snapshot starts. This is useful if you selected several counters for a data view and, therefore, a snapshot consists of several bars.

    The y-axis of the chart ends slightly above unit 700 because the highest visible value of one of the counters is just under 700. The y-axis changes when the highest value of one of the counters increases or decreases.

    The values shown in the chart represent the delta between two subsequent snapshots. For example, assume that each minute 30 lock and unlock requests are performed, which is one every two seconds. Then a delta value of 3 is shown for snapshots that are taken every 6 seconds. The delta is smaller if you decrease the refresh time and is higher if you increase the refresh time.

  3. To see which counters are represented in the data view and in which colors, click Legend.
  4. To view the values for the individual counters, you can do one of the following:
    • Click a snapshot in the data view, to view the values for a specific snapshot.
    • Click Report to get an overview of several snapshots.

    The scale of a chart depends on the threshold that you set for the counters in the data view.

  5. To change the threshold for the data view:
    1. Click Selected > Properties. The Properties window is displayed. Click the Thresholds tab.

      A threshold for a counter is specified as units per time interval. The Static scale field shows 30 units per second, which you specified when creating the data view. This means that the threshold is reached if a lock or an unlock request is performed 30 times per second.

    2. Change 30 to 60 and then click Finish.

The y-axis of the data view reflects the threshold change. Because the data is refreshed every 10 seconds, the threshold is reached if a lock or an unlock request is performed, 600 times during this period. Therefore, the red horizontal (threshold) line is now at unit 600 and the y-axis of the chart ends slightly above it.