We have 12 web sites on Windows 2008 R2 Standard 64 bit, 2GB RAM, 2 Processors. It is run in VMware at a hosting company and has been active about 2 months. ASP.Net code in Framework 4.0. No code changes or Windows Updates applied since 2/23/15.
On 3/5/15, one web (X.com) site started slowing down or stopping completely for users. There may be up to 25 or 50 users hitting it simultaneously. Task Manager Performance Tab showed CPU usage pegged at 100% and Processes Tab showed w3wp.exe IIS Worker Process for X.com.
This would last 15 to 120 seconds. Sometimes stopping on its own - sometimes I killed the process. It reoccurred at random times, getting more frequent as the day progressed. Resetting IIS and server reboot only provided temporary relief. All other web sites functioning normally, including one with twice the user load.
Only cure was to move x.com to a similar VM used for development. No incidents since.
So - what the heck??? Thanks in advance.....
1. not yet - working on that
2. No errors for the IP bound to this site, even at times of CPU=100. Lots of entries like "Timer_ConnectionIdle"
3. The Event Log did have errors about this app not being able to write to text file because it was locked. The app wrote info lines to a text file using .NET Streamwriter. I disabled this logging midday. Those error messages in Event Log stopped but the CPU problem continued. No other clues in Event Logs.
4. Yes. Database activity was 25% below normal.
5. Not sure how to check this. I didn't note excessive memory usage at the time.