Origin shield cache

Most popular media delivery workflows requires down stream servers acting as Origin shield caches. This type of configuration has become recommended method to ensure performance guarantees in media distribution, and to provide the highest possible Quality of Experience (QoE) to end users.

An origin shield cache usually seats in front of Unified Origin and between and intermediate server such as a HTTP proxy, a CDN, an edge server or even a media player. An origin shield cache can be configured based on different media delivery use cases and requirements. In this document we present some of the most popular use cases using an origin shield cache and Unified Origin. We explain each use case and we provide an example configuration using the most popular HTTP proxy servers.

Use case support per proxy server (Apache, Nginx, Varnish)

The following table provides some of the most popular Proxy servers that can be configured as an origin shield cache: Apache, Nginx, and Varnish Cache. The table indicates the general use case of an origin shield cache and its support in each web server.

  • X: it fully supports the feature.
  • TBD: requires more testing.
  • No value indicates no support for it.
  • Other value indicates the partial support.
# Origin shield use case Apache Nginx Varnish
1 Decrease upstream traffic   X X
2 HTTP response headers X X X
3 Prefetching of content TBD X X
4 Handle upstream server's limited lifetime X X X
5 HTTP response codes X X X
6 Content aware key caching URI URL URL/Hash
7 Mitigate malicious requests X X X
8 Cache invalidation/purge   X X
9 Redundant origin shield cache TBD TBD X

Load testing

For load testing other tools can be used, varying from Apache Bench (AB) to wrk to more elaborate setups like for instance the NBMP testbed.