What Information is Needed?
At this point, we have a load tester generating a set of simultaneous users, each running transactions representative of our application usage. Now we need to gather runtime performance information from our application and application server, including the following:
Application Server Statistics: memory usage, database connection usage, thread usage, and so on
Application Performance (Internal): class or method response times, call paths, exceptional methods, and so on
Application Performance (External): load tester's view of the total transaction and the requests that comprise the transaction
Platform Performance: CPU, processes, and so on.
Back-end Resource Performance: Database performance, legacy system performance, and so on
The nature of which metrics to obtain and how to interpret them will be the focus of subsequent articles.