Neither Steve nor Jim tends to take the Chicken Little approach of running around and telling people that the sky is falling. However, Jim moderated 11 sessions at Interop last week in Vegas. After hearing 30 or so vendors talk about emerging technologies he became convinced that a perfect storm is brewing and that we need to be aware of it or else we are likely to lose all ability to manage application performance. We are going to use the next several newsletters to discuss the storm and what you can do to avoid being drowned.

To put this discussion in context, we believe that it is possible for any of us to make a sequence of steps, each one of which is beneficial, and yet the final result is totally untenable. With that in mind, throughout the next several newsletter the phrase 'perfect storm' will refer to IT organizations implementing three key initiatives, each of which are extremely beneficial, and yet are ending up in a place where for all practical purposes applications cease to function.

Before we start, it is important to develop a common understanding relative to some of the issues that make managing application performance so difficult today (Compare Web Site Application and Performance Management products).

Currently, it is common to have users in a branch office access applications that are housed in a centralized data center. The way the information flows in the typical 3-tier application is data from the user’s PC transits a LAN in the branch to the branch office router. In most cases today, there is not a WAN optimization (Compare Application Acceleration and WAN Traffic Optimization products) controller in the branch office and there may or may not be a firewall. The next step is for the traffic to transit a wired WAN circuit to a data center. In many cases, there is some form of server load balancer in front of the server farm and that server farm is connected over a high-speed, low-latency network to the back-end database.

The bottom line is that in the preceding example, there is a moderate number of interconnected components that have to work as if they are one integrated infrastructure. In the typical 3-tier application the main source of variability is the performance of the WAN link. That one point of variability, however, is enough to cause applications to not perform well. In addition, if the performance of the application is degrading, it is noticed first by the end user and not by IT. Not only that, even though the end user does inform the IT organization that the application is degrading, the IT organization typically is unaware of the cause of the degradation.

Steve Taylor is president of Distributed Networking Associates and publisher/editor-in-chief of Webtorials. Jim Metzler is vice president of Ashton, Metzler & Associates.