Internet Information Services (IIS, formerly Internet Information Server) is an extensible web server created by Microsoft for use with the Windows NT family. IIS supports HTTP, HTTP/2, HTTPS, FTP, FTPS, SMTP and NNTP. It has been an integral part of the Windows NT family since Windows NT 4.0, though it may be absent from some editions (e.g. Windows XP Home edition), and is not active by default.
Today we had a problem on the server: our app was causing the application pool to crash. Windows error reporting didn’t give a clear result of what was causing a stack overflow exception within the app. No stack-trace, no nothing. So how to solve a problem like this?
I noticed that the Time To First Byte (TTFB) of my website was taking way too long. First I thought it should be resolved by caching, but I noticed that it couldn’t be the caching, because TTFB kept being pretty high. After some research I found the culprit: IPv6 with the MySQL driver.
I love SASS. What’s not to love? Well… it can’t be served directly by the web server like CSS. It needs to be pre-compiled before it is served. Fortunately there is a PHP SASS compiler that can be used to make PHP compile and serve SASS. I’m using an IIS installation, so I’ll be explaining how it can be done on a Windows machine.