Centrally hosted and globally used applications don’t always deliver satisfied user experience. Some people may argue; “don’t worry, let’s increase the bandwidth to solve our performance problem.. simple!”. Based on my experience the biggest proportion of WAN performance issues are not related to a shortage in bandwidth.
In one of my previous projects, I was involved in a performance related fire-fighting task. Some business customers from abroad claimed to be having very bad user experience. The initial analysis done by the responsible application manager demonstrated that this problem could not be reproduced and that all application components including infrastructure and database were delivering excellent response times. However, the business manager escalated this issue and increased the pressure on IT department.
So how does one investigate and solve such problems? I analysed the performance metrics and identified that there was no real user monitoring available. Therefore, I integrated a user-experience monitoring suite, which injected java script to the web pages. Using this approach I was able to measure the response times from the end user’s perspective.
An analysis of the end user performance metrics allowed me to get excellent insight into the root-cause of this issue. The login procedure to this business application was very chatty and processed 50 sub requests. For a local user with a low latency this would have been no problem at all. However, due to the high latency from Asia for instance, the login took up to 50 requests x 300ms latency 15 seconds longer.
The moral of the story is never underestimate the performance impact of your network. Make web page design analysis and real user monitoring part of your application delivery pipeline to keep your user community satisfied.