I'm trying to set up Varnish to cache certain static pages on my site for users who have not logged in or added anything to their cart.
Basically, Varnish will check whether the user has any cookies set on the site. If not, it will serve a cached version of the page. This can help dramatically when the page is under heavy load (like during a press push), where the majority of visitors won't have logged in or added anything to the cart.
The problem is, ExpressionEngine and CartThrob both set a bunch of cookies when the user first arrives, before there's any need for session data to be stored. As such, pages are (rightly) never cached by Varnish. I'm seeing these cookies set immediately on the first request:
exp_cartthrob_session_id exp_last_activity exp_last_visit exp_tracker
Ideally, neither EE or CartThrob should set a cookie until either the user logs in or adds something to their cart. Is there any way to prevent all of these cookies from being set on first visit?