3 ms·

You seem to have missed the aim of the game on their part is personalization. While it might be possible that they could do some client side processing, split t

You seem to have missed the aim of the game on their part is personalization. While it might be possible that they could do some client side processing, split the page up sufficiently, to then make multiple requests and assemble a "personalized" page, it's hard to say for certain that it would be. Certainly, it makes it less "personalized" and more "regionalized", which though being the case they describe, is likely a decision they didn't want to be locked into. For it to be truly personalized it likely needs to pull in some backend data. Given that...you can't rely on the CDN being an optimization. You could still make the personalized calls through the CDN, if you wanted and had a clear caching policy, but something like "on load, assemble a page with real time updates on the stories this person expressed interest in" isn't going to benefit from a CDN.

deleted 5y ago
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recuter 5y ago
Heh. OK for fun: They have a very finite amount of new articles a day and a little box on the page with personalized headlines. All these articles, in fact all the articles on BBC of all time ever, comfortably fit into ram if you are so inclined. Those little linodes have fast enough SSDs, try playing around and use one of countless stress loaders to get a feel. I've served hundreds of thousands of requests a second from a single server using Varnish. A well tuned beefy VPS would do tens of thousands. How to "personalize"? For example Varnish has this thing: https://en.wikipedia.org/wiki/Edge_Side_Includes https://en.wikipedia.org/wiki/Edge_Side_Includes https://varnish-cache.org/docs/6.0/reference/vcl.html https://varnish-cache.org/docs/6.0/reference/vcl.html It will happily read whatever cookie you set and stitch together a remixed personalized page for all the BBC users in the world without a performance penalty much faster than your lambda cold starts. CDNs sometimes let you hook into Varnish directly or expose something similar to essentially do exactly this. The aim of the game of the guy who wrote that blog post is to reinvent something from the 90s, but worse, and blog about it.
- lostcolony 5y ago
  It's not just new articles; it's also updates to existing. The idea then being you could put together a feed of updates of articles you expressed interest in, plus recommendations and such; this isn't what they're doing now, but it may be their long term goal and this is their path to it. I will 100% agree that what they describe in the link can be done trivially without lambda (they describe a single use case of regionalization, which doesn't even take anything special on the part of the CDN), but the point is I can easily see a future use case they're building towards, that I don't think those standards you mention will support.
  - recuter 5y ago
    I don't get why not. How do you think this was achieved before lambda? Or even before aws? It is a news site not Facebook. The feed would only ever be a subset of all the articles in cache. It can itself be cached, there are only so many permutations. Different people will have different feeds, but there will be people with the exact same feed as you. Crunch those recommendations however you want wherever you want and spew them unto S3 at your leisure. Have your varnish cache sit on top of that. Set your personalized subscriptions via a cookie. Varnish on each request will decide which one out of n (probably n<10000) feeds to include in your html response, in under 2ms. This is all stateless. Have two servers in two regions. Done. Maybe you'll reboot them every couple of years.
    - notyourday 5y ago
      Been there, done that. Can confirm it works swimmingly. It is much more fun though: don't be clever. Just cache-bust on change.

deleted 5y ago

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recuter 5y ago

Heh. OK for fun: They have a very finite amount of new articles a day and a little box on the page with personalized headlines. All these articles, in fact all the articles on BBC of all time ever, comfortably fit into ram if you are so inclined. Those little linodes have fast enough SSDs, try playing around and use one of countless stress loaders to get a feel. I've served hundreds of thousands of requests a second from a single server using Varnish. A well tuned beefy VPS would do tens of thousands. How to "personalize"? For example Varnish has this thing: https://en.wikipedia.org/wiki/Edge_Side_Includes https://en.wikipedia.org/wiki/Edge_Side_Includes https://varnish-cache.org/docs/6.0/reference/vcl.html https://varnish-cache.org/docs/6.0/reference/vcl.html It will happily read whatever cookie you set and stitch together a remixed personalized page for all the BBC users in the world without a performance penalty much faster than your lambda cold starts. CDNs sometimes let you hook into Varnish directly or expose something similar to essentially do exactly this. The aim of the game of the guy who wrote that blog post is to reinvent something from the 90s, but worse, and blog about it.

lostcolony 5y ago
It's not just new articles; it's also updates to existing. The idea then being you could put together a feed of updates of articles you expressed interest in, plus recommendations and such; this isn't what they're doing now, but it may be their long term goal and this is their path to it. I will 100% agree that what they describe in the link can be done trivially without lambda (they describe a single use case of regionalization, which doesn't even take anything special on the part of the CDN), but the point is I can easily see a future use case they're building towards, that I don't think those standards you mention will support.
- recuter 5y ago
  I don't get why not. How do you think this was achieved before lambda? Or even before aws? It is a news site not Facebook. The feed would only ever be a subset of all the articles in cache. It can itself be cached, there are only so many permutations. Different people will have different feeds, but there will be people with the exact same feed as you. Crunch those recommendations however you want wherever you want and spew them unto S3 at your leisure. Have your varnish cache sit on top of that. Set your personalized subscriptions via a cookie. Varnish on each request will decide which one out of n (probably n<10000) feeds to include in your html response, in under 2ms. This is all stateless. Have two servers in two regions. Done. Maybe you'll reboot them every couple of years.
  - notyourday 5y ago
    Been there, done that. Can confirm it works swimmingly. It is much more fun though: don't be clever. Just cache-bust on change.