问题
There is any way to ignore client "Cache-Control: max-age=0" and always let squid to return stale content?
In Squid 3.2 works using "ignore-cc" and the request never reaches backend (only while revalidating), always is stale but in Squid 2.7 works fine unless you send the Cache-control: max-age=0 and If-Modified-Since headers.
回答1:
Well, after trying all alternatives, I modified the source code to implement the feature.
I changed in the Squid-2.7-stable9 the file src/refresh.c:282:
282: if (request) {
for
282: if (request && FALSE) {
They do something like that in the 3.X to implement ignoreCc:
269: if (request && !request->flags.ignore_cc) {
Worked as expected.
来源：https://stackoverflow.com/questions/12846107/how-to-use-in-squid-2-7-the-3-1-feature-ignore-cc