The VU Activity Chart for a page or a transaction shows on the test timeline, which VUs requested the page or executed the transaction on different test iteration. It also shows on which agent it was emulated.
The VU Activity Chart helps to isolate performance issues by showing how load patterns and VUs concurrences correlate with slow pages/transactions. You can further drill down every page/transaction to display its waterfall, which breaks it down to the level of individual requests.
An example of a transaction VU Activity chart is provided on the right:
- Vertical axle shows VUs (a).
- VUs 1-250 were emulated on a controller (b); VUs 251-500 were emulated on the agent (c).
- Horizontal axle (d) is the timeline. The test duration was a little longer than one hour.
- To zoom-in to a specific VUs/Iterations range, select an appropriate rectangular area (e).
- Each page or transaction associated with a VU is depicted by a sequence of horizontal bars colored to highlight the alternate iterations: iterations, 1,3,5... are dark green (f); 2.4.6... are light green (g).
- The length indicates how long it took to complete the page or transaction on this iteration.
- To display details of each page /transaction, mouse over its bar (h). The tooltip (i) will display the following information:
- VU number
- Iteration number
- Iteration start and end time
- Page/transaction duration
- Page/transaction duration w/o think time
- Agent name
- Test case name
Generating Test Iteration Waterfall
- To display a waterfall of a page/transaction, Dbl-Click its horizontal bar, or right-click (j) and select View Waterfall.
- You can compare the waterfalls of two iterations. To do so, after selecting the first waterfall, navigate back to VU Activity view and Ctrl+Dbl-Click the second iteration bar, or right-click it and select Compare Waterfalls.
- To zoom-out, right-click (k), and select Un-Zoom.
- For additional context menu commands, right-click and select Copy Image, Save Image or Print Graph Image.
When zooming the activity view, the bottom area will show iteration summary information for the zoomed range.