As part of our coverage of the state of network optimization, I asked Hon Wong, CEO of Symphoniq (and former co-founder of NetIQ), to weigh in on the challenges of Web application performance.

Symphoniq’s software monitors Web applications to provide IT with a picture of what end-users are experiencing and to automatically detect, diagnose and pinpoint the root cause of performance problems before they become widespread. (Compare Web site application and performance management products)

Here’s what Wong had to say about the impact of technologies such as virtualization, service-oriented architecture (SOA) deployments and more.

What are the biggest challenges for enterprises these days, in terms of Web application performance management?

Traditional enterprise tools focus on measuring the availability and performance of various server or network components. With today’s complex Web applications, especially with the adoption of virtualization, cloud computing, Web 2.0, etc., it is not the performance of individual technology silos that matters, but how the complex interactions of these technologies or platforms impact the performance as experienced by the end user that is important to the enterprise’s bottom-line. The challenge is not in measuring CPU consumption or number of network connections, but in understanding end user experience and relating that to causes of performance problems. Certainly one cannot manage what one cannot measure, and the only true measure of Web application performance is at the point where the application comes together at the end user’s browser.

Do application delivery controllers and WAN optimization devices make it harder to monitor application traffic from end to end? How do you get around these obstacles?

Acceleration appliances for both Web and WAN applications offload traditional server functions like load balancing, caching, compression, security and firewall functions to dedicated appliances in order to improve application performance without having to deploy more server or network resources. The side effect is that one can no longer assume that there is a strong, direct correlation between server and end user performance. In other words, one cannot assume that the end user is receiving the desired level of performance even if the server is running well. The way to determine whether the end user is receiving the desired level of performance or that the Web or WAN accelerator is delivering the expected level of performance improvement is to directly measure and analyze end user performance information. The variation in end user performance, before and after the activation of the acceleration appliance, can be used to tune the appliance for improved application performance.

Ann Bednarz is associate news editor at Network World.