I have a server running windows server 2008 R2, recently my websites have becoming unresponsive at least once a day, seemingly at random intervals.
I have installed some monitoring software and noticed that the anonymous user count spikes when this happens, it normally averages around 100-200 users, but the spikes are jumping to around 400-700 users.
This has only recently started to happen in the last few weeks, a restart of my IIS Server fixes almost immediately.
What should i be doing to investigate this further, what could be causing these spikes?
My initial thought was it being a spider crawling my site at a ridiculous rate, but i'm not sure how to determine if this is true or not.
Any advice is appreciated.