[moe]

I haven't used nginx caching in depth, but I can make a more general point about nginx scripting: It sucks. Hard.

You can get fancy[1] by writing your own modules or by building on top of helpers like ngx_devel_kit, but it gets messy very quick.

Implementing complex rules inside the config file is possible to a degree - but an utter nightmare. The syntax is extremely limited and the semantics are hard to predict (order of execution).

So, what nginx is lacking is a proper scripting interface with full control over the request pipeline. ngx_lua and ngx_v8 are in the works but not production-ready, yet.

Personally I'd go as far and say the entire config file should simply be ripped out and replaced with a scripting language.

[1] http://agentzh.org/misc/slides/nginx-conf-scripting/nginx-co... (press cursor right to walk through slides)

[piotrSikora]

ngx_lua is production ready [1].

[1] http://github.com/chaoslawful/lua-nginx-module/commit/26d9dc...