server side caching on ubuntu.com

[tbille]

original comment https://github.com/canonical-web-and-design/ubuntu.com/issues/8686#issuecomment-722954230

Hello,

This is a consequence of another issue, which is more of a "design" one. Some pages visited upon hitting www.ubuntu.com try to hit discourse.ubuntu.com to download some json file.

A fix has been committed yesterday (#8675) to avoid hitting the rate limit, but the issue is that if discourse.ubuntu.com goes down, several pages are going to reply a 500 to the end user. Content-cache won't help here, as it will try to validate the cache, sees a 500, because flask will have gotten a 500 from discourse and the end user will end up with an error.

I think we need a sort of cache for every request made to discourse.ubuntu.com and fall back on the last know working copy on the flask side.

What do you think ?