Methods of HTTP Caching


I find the world wide web and the spectrum of methods and instruments that make it happen full of dubiousness and opportunity alike. Caching is generally known as one of the „hard problems“ of information science, and this is not different when it comes to technologies of the web. The text presented here, as unsorted and questionable as it might be, can in the least serve to document this further.

The bulk of this text was written between December 2019 and January 2020. It contains a summarization of my experience as an administrator and developer of web-based applications, some research about current subjects (specifically browser caches and reverse-caching HTTP proxies) and references to relevant IETF standards.

I release this text on an „as is“ basis, and, as it is currently lacking any form of review, accuracy or even correctness can not be guaranteed. I intend to, from time to time, revisit this document to fix errors or update it to recent developments. To keep references to this text intact, such updates shall take the form of additional notes (formatted like this) that carry the date of the introduction of that addition. Please expect not too many updates or a high update frequency, because i have a busy professional life.

You are very welcome to report all errors (typing, factual or otherwise) you will find in this text to me, they are in all likelihood my doing; i will gladly consider them, and, if appropriate, fix them in an errata-release. If you express your wish for me to do so, i will attribute you by your name in a note accompanying that errata-release, otherwise i will attribute you as „an anonymous reader“.

Kind regards,
Spechbach, Germany, February 2021