Hacker News Reader

Comment by daxfohl | Hacker News Reader

This isn't really edge. It's multi-region. It's a great intro to multi-region considerations, but it's not edge.

Edge implies putting your stuff in a CDN-sized datacenter that has only a subset of the full regional services, may not be able to scale up significantly on demand, may be more expensive, have less local storage and failover redundancy, etc. The multi-region considerations come in here too, but there's a whole extra set of things to worry about.

Basically you rarely want to deploy your whole app to edge; have a central or multi-region thing under the hood, and let the edge handle some very specific functionality. And even then, only if a few ms of latency makes a big difference to your clients (and they can deal with the lack of failover redundancy).

View on HN

Edge IMHO implies being (very) close to the customer. As in, for example, IoT or running a service in an Internet Point of Presence maybe. But once your "in the cloud", you're not really on the Edge anymore.

But the term seems to get used for everything and anything apparently.

Yeah I don’t get how anything in a data center can be called edge.

That's just moving goal posts. Now you have to define what's a data center.

Your home or office with a bunch of computers can be classified as a data center. It might not be very redundant or efficient, but still.

I think a reasonable reader can figure out from context what “data center” means. If you have a bunch of computers in a home or office you might call it a rack, or a network closet, maybe a server room. Most people won’t call it a data center.

If you complain that the definition of “data center” is inexact, you’re missing the point—the definition of “edge” is inexact, too. That’s okay. People have a good enough definition of “data center” that it doesn’t need to be explained here. And people also understand that given definitions are not perfectly precise—there are exceptions and unusual cases.

> Your home or office with a bunch of computers can be classified as a data center.

Only in the way that a plucked chicken is a man. (http://www.artandpopularculture.com/Featherless_biped)

Well I could see it if it’s the customer’s data center.

How would you describe hosting a static website in Singapore and in New York on AWS?

Multi region, definitely not even close to edge. If you want static site on the edge why not just use Cloudflare Pages

This was just an example. If the users are in Singapore and the USA. I'm not sure what would be more 'edge' than this configuration.

More 'edge' would be colocating your equipment in each major New York ISP's data center. One box for RCN, one for Optimum, one for Verizon...

But some people would say if it's in any kind of data center, it's not true edge.

You do realize that users travel right? And that the US is absolutely massive and there are wide latency differences between coast to coast? Using two DCs isn't "edge"

Multi-region redundancy? Still not at the “edge” because I’m using your NY instance from Atlanta.

Geolocation-based load balancing, geo steering, something along these lines.

Depends a bit on wether traffic from Singapore would be allowed to go to NY if the Singapore host goes down.

Eh, I've always defined "edge" as the closest piece of compute infra to your client. Could be a VM, a load balancer, an API gateway, a service worker, whatever. Arguing it's part of your CDN is just letting Cloudflare's marketing department coopt the term.

The closest piece is the client router. Then a ton of switches on the way. I get in gist what is meant here, but it's really hard to define so simply.

Here's the definition of "Edge Computing" from State of Edge 2022

> The delivery of computing capabilities to the logical extremes of a network in order to improve the performance, operating cost and reliability of applications and services. By shortening the distance between devices and the cloud resources that serve them, and also reducing network hops, edge computing mitigates the latency and bandwidth constraints of today’s Internet, ushering in new classes of applications. In practical terms, this means distributing new resources and software stacks along the path between today’s centralized data centers and the increasingly large number of devices in the field, concentrated, in particular, but not exclusively, in close proximity to the last mile network, on both the infrastructure and device sides.

Ps. I work at https://edgenode.com

The meaning of "edge" keeps changing but currently it just means when your CDN provider offers compute services.

To CDNs marketing their compute-in-CDN products, sure.

But to people selling "Edge AI" products, an edge device is something like a smart speaker or industrial camera.

With industrial camera it is probably the device where multiple cameras connect to. With industrial solutions you often want a gateway that is edge device between the internal and external network.

At least that is my current IIoT definition. You could have bunch of pretty dump sensors and then somewhat beefy these days gateway. And the gateway here could do some computation.

There is a clear distinction between edge and a region. That distinction is defined by the distance and by relation latency. Edge locations are not heavy regions or data centres, per my understanding and hence limited by compute/storage capability. They are also high in number. Cloudflare has 100 odd edge locations all around the world.

Cloudflare and Akamai both have the concept of edge workers - light weight application APIs that can serve modest capacity. Cloudflare also has a cache on the edge.

https://blog.cloudflare.com/introducing-cloudflare-workers/ https://developers.cloudflare.com/workers/learning/how-the-c...

They're all data centers in essence; some are way smaller, less functional and some way bigger. But still much smaller than regional DC's (the cloud). Akamai has smaller ones, and hence 1000's of them. While Cloudflare and Fastly have larger PoP(Points of Presence) and a few 100's of them.

I think this is a network architecture detail, and is using the term "edge" in a subtly different sense than the article is. We have "edge" hosts and "worker" hosts where I work, but "edge" means "the edge of our network, where requests from the Internet land", not "deployed as close as possible to users".

> Basically you rarely want to deploy your whole app to edge; have a central or multi-region thing under the hood, and let the edge handle some very specific functionality.

Exactly. Example: We wanted / needed to deploy on the edge. Use case: A very very small part of a live streaming service, basically cache preloading functionality, as well as authentication / session management / DRM. All the rest would be handled by some upstream service.

In terms of the theory covered here it doesn’t really matter whether the edge is a cloud region, CDN, server in your building, or personal device. I don’t think any of these havent been tried as nodes in a distributed transactional database. It’s kind of just a semantic argument - the network failure rate, availability, and capacity to scale horizontally within your “edge” node are just parameters.

Imagine this: within a CDN’s compute you try to serve distributed db transactions optimistically then fall back to your big cloud region when it fails. The CDN is kind of a write-through cache. You still have to address the CAP theorem distributed state challenges of synchronizing state and making a consistency/availability/partition tolerance tradeoff, and it seems like a reasonable use of a CDN.

Exactly .. looks like the author don't really have experience in the possible capabilities of a good CDN network and more so in designing the software architecture in a way to take advantage of a good CDN network.

Thank you, and this actually is an important distinction, and not just pedantry

Hardware becomes the limiting factor when you’re talking edge versus multi region where hardware is one of many limiting factors, but often network is the more important factor as indicated in this link

Edge also has the distinction of being hardest to instrument for observability and often is required to work in multiple environments.

Huh, I thought edge was essentially IoT devices. Smart toothbrushes. Calling a datacenter edge seems odd.

The DC guys have co-opted the term "edge" for marketing and fund raising purposes. A former colleague was talking about a 10's of megawatts "edge" DC in Jakarta that they were building, I couldn't help but chuckle.

Edge is always one hop further than you currently are. If

Reply on news.ycombinator.com