One of the core principles that guides the design of the XPRT tools is they should reflect the way real-world users use their devices. The XPRTs try to use applications and workloads that reflect what users do and the way that real applications function. How did we learn how important this is? The hard way—by making mistakes! Here’s one example.
In the 1990s, I was Director of Testing for the Ziff-Davis Benchmark Operation (ZDBOp). The benchmarks ZDBOp created for its technical magazines became the industry standards, because of both their quality and Ziff-Davis’ leadership in the technical trade press.
WebBench, one of the benchmarks ZDBOp developed, measured the performance of early web servers. We worked hard to create a tool that used physical clients and tested web server performance over an actual network. However, we didn’t pay enough attention to how clients actually interacted with the servers. In the first version of WebBench, the clients opened connections to the server, did a small amount of work, closed the connections, and then opened new ones.
When we met with vendors after the release of WebBench, they begged us to change the model. At that time, browsers opened relatively long-lived connections and did lots of work before closing them. Our model was almost the opposite of that. It put vendors in the position of having to choose between coding to give their users good performance and coding to get good WebBench results.
Of course, we were horrified by this, and worked hard to make the next version of the benchmark reflect more closely the way real browsers interacted with web servers. Subsequent versions of WebBench were much better received.
This is one of the roots from which the XPRT philosophy grew. We have tried to learn and grow from the mistakes we’ve made. We’d love to hear about any of your experiences with performance tools so we can all learn together.
Eric
