Correlate Multiple Sources of Data for the Same Run
Using Excel, you can take data from all sorts of sources and combine it to help identify patterns and trends in the data. The "textbook" example from Scott’s article illustrates this about as well as I’ve ever seen (see Figure 5).
Figure 5 Combining data in scatter charts. (Image courtesy of Scott Barber and IBM.)
By overlaying your performance test transactions with data from other monitoring tools (WhatsUp, Introscope, Sysmon, jstat, etc.) and with the different types and sizes of data that you use in your test, you can see which aspects of system performance correspond with the various transactions in your performance test. I especially like to correlate data with transaction performance if I can.
On a previous web service project, I was able to tie a specific XML transaction to a bottleneck and found that a specific element caused a (very slow) rule to fire in the web service that no other XML file could. Again, change the colors of the different variables to help make sense of the data.