How do I replay a scenario, caching image files but not text files?
The Grinder itself does not cache files. It merely simulates browser behaviour. The Not-Modified-Since headers are recorded by the TCPProxy filter, so what you record with the TCPProxy is the caching behaviour of the browser you are using. If this is not what you want you could add a function to your test script which takes an HTTPRequest, decides whether it should be considered as “cached” or not, and adds a Not-Modified-Since header as appropriate.
