Proxy Cache - How to Always Return Stale Content

natiiziv · 2018-01-15T19:35:22+00:00

Is it possible for the ngx lua module to access the shared memory space that keeps a dictionary of fastcgi cache locations? If so, how?Additionally, is there...

Proxy Cache - How to Always Return Stale Content

natiiziv

Hello,

My use case is simple:
1) Serve static files coming from an upstream (using proxy_pass)
2) If the upstream returns a non-200/304 response - ALWAYS serve the file from cache, even if its expired/stale.

For the most part, 'proxy_cache_use_stale' does the trick.
However - it doesn't cover cases such as 401, 402, etc. (the full list it does support according to the docs: error | timeout | invalid_header | updating | http_500 | http_502 | http_503 | http_504 | http_403 | http_404 | http_429)

Is there a way I can achieve this? how can I force the file being served cache for the cases not covered by the 'proxy_cache_use_stale' directive? (even if it requires using lua)

zchao1995

Hello!

It seems that there no way to achieve this unless hacks the source code(e.g. add some extra ft_type for upstream cache).