ARR, Caching and Ajaxtoolkit files
A fun little episode today.
We're moving a website that uses Ajaxtoolkit to an ARR based web farm.
One of the pages would show OK the first time and then subsequent calls would show the code from common.js.
We had no idea what common.js was.
We could see files in ARR's cache and the page worked fine when not going via ARR, but had no idea what was going on.
Changing ARR's cache to "do not cache" for query strings made it go away, but that didn't really satisfy me as to why it was happening.
Changing to "Include query string" was the eye opener. This put three entries in the cache for the file scriptresource.axd each with a unique query string.
Any subsequent calls to the page worked perfectly.
Further reading revealed these files are generated at runtime so when the default of "ignore query string" was turned on, a single file was generated and cached when the page actually required the different versions to work.
I won't pretend to understand what the Ajax toolkit is up to (web development really isn't my thing), but tracking the problem down was a barrel of laughs.