HTTP Caching Headers

I recently wanted to add some rather aggressive caching, to prevent my server getting hit too often.

Naturally, I wanted this caching to take place on the client, i.e. the webbrowser.

So, there have traditionally been advantages and disadvantages to caching.

Advantage: the server doesn't get hit again, and your website feels more responsive.

Disadvantage: it is possible to see outdated cached data.

Invalidating cache entries is basically an entire study of its own.

In my case I took the obvious route: the data stays the same forever.

This facilitates my caching wonderfully.

response.addHeader("Cache-Control","private, max-age=31536000");

This stores the item in the cache for one year (31536000 seconds).

Private means caching in the client browser, public means that it might also be elligible for caching in all other intermediaries between de browser and the server.

The blogs in the references are very clear.

References

[1] Heroku Dev Center - Increasing Application Performance with HTTP Cache Headers

https://devcenter.heroku.com/articles/increasing-application-performance-with-http-cache-headers

MDN Webdocs - HttpHeaders - Cache Control

https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control

MDN Webdocs - HTTP caching

https://developer.mozilla.org/en-US/docs/Web/HTTP/Caching