Web applications may send a special HTTP method OPTIONS to query an API for functionality. If supported, the answer is a bunch of clear text HTTP headers. An OPTIONS request is usually quite lightweight for the server, but it still uses resources like connections and CPU time. The answer to an OPTIONS request seldom changes unless the API itself changes. So we have small HTTP text objects that seldom are updated. Sounds ideal for caching with Varnish.
Varnish is the ... [continue reading]