We had IIS 6 on Win 2003, We upgraded to Win 2008 and now our app is same, basically its a simple file server to resize images and cache them and deliver to clients. Since resizing requires more memory size, running under Pipelined Pool causes no more memory errors so we went back to Classic mode and there is no ther website, only one and we are happy with it.
Today morning I saw the website was down, and I went and checked CPU Usage of server, it displayed 100% CPU usage by w3wp.exe, now we never had this problem before, the code is same that we did use in old IIS 6 and its simple Database read and Response.Write..
Restarting server solved the issue, but if I get same problem again, how can I check which part of code of our website did use such a huge cpu usage where else there is absolutely no error log and no event viewer error as well.
The code that is used in website is hardly few lines, typical DAL query to database and response.write thats all. Files are stored in blobs in database but that has nothing to do with anything because it did run successfully for 3 years with same SQL Server. The only change is IIS 7 and its Classic Application pool against IIS 6 with default app pool.
I would appriciate any tool or anyway to atleast monitor what caused this problem. We have Win 2008 running since last 30 days and we only got this error once.