I am using varnish for reverse proxy and apc for op-code caching.
Have anyone used both for same site ?
Is there an overhead between compatibility between both ?
My personal opinion is that both are not into each other domain but wanted a quick opinion based on any personal experience.
Thanks
You're correct they're not in the same domain.
There is no overhead for using both. APC functions underneath your PHP system and speeds up your PHP execution time.
Varnish sits between your browser client, and your HTTP process (apache/lighttpd/etc) and caches visits to the webserver.