New Delhi Times - Gaurav Bhatnagar reporting from New Delhi, India

Last week, one of the testers on my project filed an interesting bug. Apparently, loading one of the asp.net pages was taking too long. What's more, after a minute or so, the CPU would heat up so much that the fan would start whirring! Even though it wasn't assigned to me, the bug description was interesting enough to get me curious. The first step was to obviously break into the debugger. Since the page was taking very long to load, I suspected that a thread was blocking on something. It turned out that the main render thread was blocking in a "Array.Copy" operation. Looking at the call stack, it turned out that hundereds of deserialization operations were taking place. That gave me a clue. ASP.NET was trying to deserialize the Viewstate. A quick look at the code revealed that we were saving off a huge dataset in the Viewstate. Serialization and deserialzation are expensive operations and more so for a complex data type like datasets. We removed the dataset from the Viewstate and things cooled off considerably after that ;)