Setting up events-based sampling
In Streamline, you can override the default interval sampling with events-based sampling using the Counter Configuration dialog box.
To enable events-based sampling, follow these steps:
- Open the Counter Configuration dialog box using the button in the Streamline data view.
- Select an event from the Events to Collect list.
- Click the Toggle events-based sampling button on the right side of the dialog box. If the Toggle events-based sampling button is not selectable after you have selected an event, then that event does not support events-based sampling.
Enter a value in the newly activated Threshold
Avoid setting a very low threshold for high frequency events. If you enter
a threshold value that generates too many samples, Streamline could fail, and you
might have to restart your target. To find an appropriate value to enter in the
Threshold field, turn off events-based sampling to
run a standard, time-based profile with the event counter that you want to use
enabled. Look at the resulting Timeline view and note the
peak per-second value in the chart for your counter. Your target for the
Threshold field is 1000 samples per second, so if the
peak for that event is 2000000, a good value to insert in the
Threshold field is 2000.
Figure 4-5 Setting up events-based sampling