Best way to cache RESTful API results of GET calls

Question

I'm thinking about the best way to create a cache layer in front or as first layer for GET requests to my RESTful API (written in Ruby).

Not every request can be cached, because even for some GET requests the API has to validate the requesting user / application. That means I need to configure which request is cacheable and how long each cached answer is valid. For a few cases I need a very short expiration time of e.g. 15s and below. And I should be able to let cache entries expire by the API application even if the expiration date is not reached yet.

I already thought about many possible solutions, my two best ideas:

• first layer of the API (even before the routing), cache logic by myself (to have all configuration options in my hand), answers and expiration date stored to Memcached

• a webserver proxy (high configurable), perhaps something like Squid but I never used a proxy for a case like this before and I'm absolutely not sure about it

I also thought about a cache solution like Varnish, I used Varnish for "usual" web applications and it's impressive but the configuration is kind of special. But I would use it if it's the fastest solution.

An other thought was to cache to the Solr Index, which I'm already using in the data layer to not query the database for most requests.

If someone has a hint or good sources to read about this topic, let me know.

Answer 1

memcached is a great option, and I see you mentioned this already as a possible option. Also Redis seems to be praised a lot as another option at this level.

On an application level, in terms of a more granular approach to cache on a file by file and/or module basis, local storage is always an option for common objects a user may request over and over again, even as simple as just dropping response objects into session so that can be reused vs making another http rest call and coding appropriately.

Now people go back and forth debating about varnish vs squid, and both seem to have their pros and cons, so I can't comment on which one is better but many people say Varnish with a tuned apache server is great for dynamic websites.