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bragr • 10/01/2024 • 2 replies • view on HN

Having a CDN doesn't help your performance when you tell it not to cache the page

  bragr@<>:~$ dig +short community.silabs.com
  community.silabs.com.00da0000000l2kimas.live.siteforce.com.
  sdc.prod.communities.salesforce.cdn.edgekey.net.
  e78038.dsca.akamaiedge.net.
  173.223.234.17
  173.223.234.11
  bragr@<>:~$ curl -Is https://community.silabs.com/s/share/a5UVm000000Vi1ZMAS/quake-ported-to-arduino-nano-matter-and-sparkfun-thing-plus-matter-boards?language=en_US | grep -i cache
  cache-control: no-cache,must-revalidate,max-age=0,no-store,private
  x-origin-cache-control: no-cache,must-revalidate,max-age=0,no-store,private
That said, the assets are cacheable so there was probably just a thundering hurd for the assets until they were well cached by Akamai's mid and edge tiers

Replies

toast0 • 10/01/2024

When I've used a CDN, there were separate headers to control the CDN with the same semantics as cache-control... so you can serve the cache-control you want to browsers and control the CDN separately.

If it doesn't feel like it's cached, it probably isn't; but you can't assume the cache-control headers you see are controlling the CDN.

➕ show 1 reply
iknowstuff • 10/01/2024

ugh, old.reddit.com sends a no-store when signed in and its driving me mad because it breaks back/forward cache.

➕ show 1 reply