Performance monitors
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The use of the Internet for mission-critical services has put a focus on managing web application performance.
As the deadline for submitting online tax returns to the UK's Inland Revenue approached in January 2005, users of the web site were the first to notice a problem: some were given error messages; others a helpline number; in the worst cases no message was given, leaving some thinking they had managed to submit their return, unaware that the system had failed and leaving them open to a hefty fine.
Ultimately, the Inland Revenue acknowledged the problem, granting tax payers more time and suspending fines for those that had genuinely attempted to meet the deadline. But it did not explain why its IT management had misjudged the performance issues so badly and web applications that had been years in development were unable to cope with demand.
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The Inland Revenue is far from alone in suffering the ignominy of seeing its web site overawed. Famously, the Public Record Office proudly announced the online availability of the 1901 Census of England and Wales in January 2002, only to see the £1.2 million site buckle under the strain of eager genealogists. Eleven months passed before users were offered full access to the system again.
At Information Age's August roundtable debate, the business continuity manager at a large insurer highlighted just how damaging such incidents can be to commercial organisations: "If the web site is down, then 50% of our business disappears - not to mention the impact on to our brand and reputation."
One of the difficulties of running web applications is that there are so many factors that can affect performance and delivery. As web services mature and enterprises shift towards a service-oriented architecture, the notion of what a web application actually looks like is changing. Indeed, what seems like a seamless front end to the web user may hide any number of interconnected applications, databases and servers - both new and legacy.
The job of ensuring satisfactory performance can be made easier by iterative testing during application development, said Andre Serpa, technical services manager in the EMEA region for web applications performance software company Empirix. "If you only test when the application is finished there could be any number of problems," he says. "But if you do performance testing as you go along, you see whether any changes made to, say, the database schema, are affecting performance."
But finding the time and the budget for testing is a challenge in itself. The head of IT architecture at one of the UK's largest pension providers said that, while recognising the benefits, time pressures invariably resulted in testing programmes being squeezed. "How you manage that conflict between delivery and reliability is still very much up for debate."
