Over the last year I have gotten an education on PHP and MySQL web sites to go along with my existing expertise with ASP.Net and SQL Server.
It turns out that I purchased a web site a little over a year ago that supports gamers who play World of Warcraft (a game I have played for years). The site gets about 100,000 unique users a month with just shy of a million page views a month. The site was written in PHP against a MySQL backend and is just not driving the revenue yet to justify porting it to ASP.Net and SQL Server (though as you will read here the balance of pain is shifting that equation). It turns out that we end up rebooting the system pretty damn often which was a problem with IIS back in the old days, but not one I have had in recent versions.
We have thrown more hardware at the system, brought in professional help and it just seems that at these levels of use the system runs down and needs a kick and sometimes intensive care.
My point here is that it has been an education for me to validate what I suspected, there is no magic with the non-MS stack. It can hang in some regards, but it seems that for really heavy loads, MS has got them beat on stability. I am working on an ASP.Net with SQL Server site now that handles similar traffic and it just doesn't suffer the same issues.
I plan to dig deeper into the tech here if for no other reason to figure out what it takes to port the site to ASP.Net with SQL Server.