A number of questions have come up regarding 304s.

The browser as part of the GET includes a header called If-Modified-Since (it appears as HTTP_IF_MODIFIED_SINCE in the REQ).? Along with this header is a date corresponding to when the object is cached.? It is up to the web server to look for this header and compare the date.? Most web servers support this as an option.

If the web server supports the option it returns a status code 304 telling the browser to use the local copy.? This results in a REQ-RSP pair with a zero byte response body.? This is quite different from hitting back and getting a page from local-memory cache (where no REQ happens).

The browser only includes the header if it finds a copy of the object in its local cache.? This only applies to cacheable items (gif htm etc).? This does not correlate to in-memory cache although it is entirely up to each browser how it is handled.? In the case of IE they are stored as Temporary Internet Files and stay until you delete them in Internet Explorer (IE) Internet Options.? Closing a browser and reopening it does not avoid 304s.

If you have Load Remote 304 pages checked in the viewer it does a GET operation that does not include the If-Modified-Since header so the webserver returns the object. However that does not mean RealiTea Viewer (RTV) actually gets what the user saw.? Any redirection that occurs as a result (such as to the home page) is not immediately obvious when replaying as session.? Normally the option is turned off.

00000133