Cache miss at a CDN edge server

Question

Upon cache miss at a CDN edge server:

1. the server might redirect the end-user to another CDN server that has the content or
2. it might try to download the solicited content from the producer, cache it, and then respond to the end-user.

Now, if this understanding is right then how the second solution works for very big files (like a movie). I just do not understand how the edge server can put the end-user on hold for several minutes to download the content from the producer and then sends it to the end-user!!

Answer 1

The CDN won't delay the user more than the origin (producer) would.

In the case of streaming a movie, with or without a CDN between you and the origin, you don't download the entire movie and then play it (neither does the CDN), you download the movie in chunks while playing the previously downloaded chunk (and the CDN does the same, and caches the chunks).

btw, a CDN can actually accelerate downloading big files or dynamic content, even if it doesn't hold it in cache, by accelerating TCP, and other cool techniques.