Let redirects be short-term cachable

[da2x]

Please let redirects themselves be temporary cachable by clients. Seems unnecessary for each client behind a proxy to require to refresh the redirects every time.

I’d suggest to make it cachable for 5 or 10 minutes. Should reduce load on httpredir.debian.org and speed up upgrades in proxied environments with many clients. I don’t really know what the ideal time would be, but at least five minutes.

Cache-Control: max-age=450  # 7,5 minutes

[2vek]

Wouldn't this kill parallel downloads? debian bug#158486

Having no cache is feature actually, see httpredir homepage under "Advantages over mirror:// method"

Per-request decision making: no need to apt-get update to choose a different mirror.

[rgeissert]

The redirections that are served with a 307 status are really not meant to be put in a time-driven cache. The files, or objects, behind those names are replaced in-place and it is the redirector the one that is controlling the view that is presented to the user.

I would be happy to add an etag or similar that would allow the proxy to cache to revalidate the response if proxies actually support that, but TTBOMK they don't. Moreover, apt sends a cache-control: must-revalidate for all the indexes - which are the most relevant files for which a 307 is used.