Tiered Cache, how geographically works?

[bruno.silva010104]

Good morning, and Happy New Year to everyone!

So, I already knew that Cloudflare was a new feature called Tiered Caching. And I kinda understood the function, and etc.

But, one question I have: how “geographically” the Tiered Cache works? Ok, maybe I’m gonna do a map to explain my idea.

Ok, so, I actually live in Portugal. So far, so good.

Without Tiered Cache, the LISBON server is going to request the content directly to my origin server. Again, so far so good.

But, if I have activated Tiered Cache, the LISBON server is going to request a “master” server that is located at the same datacenter, or it’s going to request from a bigger datacenter, like Madrid or even Paris?

Maybe another example, imagine that I have a person requesting my website from MILAN, Italy. Again, the MILAN server it’s going to request a “master” server located in the same datacenter, or is going to request a bigger datacenter, like Paris, or even, a bigger one located in Italy?

Thank you for the patient, and Have a Nice Day!

[sdayman]

It wouldn’t be in the same datacenter. I’ve not seen a network map that shows the heirarchy, nor do I think there’s one publicly available. I’ve been curious about this, but it’s not something I’ve dug into. I don’t even see any analytics for tiered caching.

Is there something specific you’re trying to analyze?

[bruno.silva010104]

Hello, and first of all, thanks for the reply!

I mean, it’s just because bigger DC’s from Cloudflare have more capacity than smaller ones, and if the smaller ones, on Tiered Cache, requests the content from bigger ones, that could be better in my situation.

I have a very specific situation that I’m seeing poor performance from Cogent at LISBON DC, and if the problem is about routing things, maybe Tiered Cache can help me, only if the Tiered Cache requests the content from another DC than LISBON. But that’s not my main focus.

And of course, for my curiosity, and for some other users.

EDIT: and about the routing situation, seems that the LISBON DC doesn’t have a direct connection to Level3, and needs to go through Cogent. If, for example, the Tiered Cache requests content through a DC in Spain or even France, maybe the chance of using Cogent is lower, I guess because I think they have more routes in Spain and France than Portugal.

[bruno.silva010104]

So, this is what I talk about:
LISBON DC to 2 different IP addresses:

PARIS DC to the same 2 IP addresses:

[sdayman]

I don’t see what Tiered Caching has to do with this. All caching happens behind the scenes via connections internally (if cached), or to the origin (if not cached). You’re looking at connections to the proxied website. That’s not going to change due to any Argo product.

Here’s a bit more about proxied connections:

Deprecated - Peering - Why don't I reach the closest datacenter to me?

This tutorial is deprecated in favour of https://www.cloudflare.com/en-gb/learning/cdn/glossary/anycast-network/

Archive

Why don’t I reach the closest datacenter to me? Cloudflare is an anycast network, so where you are routed is determined by peering with ISPs. The shortest path geographically isn’t always possible due to peering agreements. If you request a site hosted on Cloudflare from home: The domain resolves to a Cloudflare IP Your browser sends an HTTP request to that IP Your ISP’s r…

[bruno.silva010104]

I mean, if the LISBON DC started querying the PARIS DC, theoretically the data travels from Origin-»Paris-»Lisbon. And if they enter “the network” at Paris, they’re gonna use a different route than Lisbon.
again, this is what I think, I’m not sure about that.

EDIT: and ofc, from Paris to Lisbon, probably they’re using an internal route between the datacenters

[sdayman]

I think you’ve got the idea. Un-cached Cacheable content does take an extra hop when using tiered caching.

Introducing: Smarter Tiered Cache Topology Generation

[bruno.silva010104]

Hello again,

Thanks for the confirmation. In my situation, maybe Tiered Cache can be helpful to “not use” most of the time the Cogent’s network to connect to the origin, at least here in Europe, which is my main focus for now.

I’m going to test this and provide some feedback at times of higher traffic, because apparently, Cogent likes to saturate here in Portugal.

Thanks one more time for all the answers, and of course, the knowledge

[bruno.silva010104]

So, I got an update about my question. I have the results of speed on a high traffic time, With vs Without Tiered Cache:
With:

Without:

At another time of the day, the differences aren’t too significant (only 3-4MB/s of difference)