4 ms·

not the CDN going down. the client being unable to reach the CDN. the http request the cdn to get the file is not a 'free' operation. network timeouts take tim

• oinksoft 13y ago
  I mean the CDN going down from the end user's point of view. Why the host is unreachable is a moot point.
  • lerouxb 13y ago
    I see this daily, but then I don't have a sub-20ms ping time and a cable modem where I live. The CDN doesn't have to go down. The user's connection doesn't even have to go down. Things just have to get momentarily flaky _somewhere_. I'm working on a project that uses google fonts and the page loads with fonts timing out multiple times per day. I get to sites where just the html loads and none of the css (or worse: just some of the css) all the time. Especially on 3G, but regularly on ADSL too. Or what if you're sharing a saturated line? (And waiting for a timeout to kick in before you trigger a callback is just not an option. By then the user probably closed the page anyway. Rather just make it work in the first place.)
• xtreme 13y ago
  You should optimize the common path, not the edge cases. Most of the time the user would be benefited (cached content = faster load) from using CDN. On the other hand, CDN being unreachable is not a very common scenario, so it is acceptable to be a little slower.
  • Jach 13y ago
    CDNs are already an edge-case optimization, provided that unique visitors is less than number of visits.