The term “Edge computing” is starting to get a lot of air time, along with suggestions it might blow away clouds and get the likes of Amazon and Microsoft trembling.
It won’t do that. Indeed, it might just give the big clouds an interesting extension.
To understand why, let’s define Edge. Which is easy: it’s all about putting servers and storage out where data gets made and people do work.
To understand why that’s useful, consider the “Shelfie”, pictured above, an Australian-developed drone that flies around supermarkets snapping pictures of shelves so that software can figure out if there’s product there for punters to buy. If a shelf is empty – Bam! – off goes an order for more stock.
The Shelfie uses Microsoft’s Azure cloud to do its analyses. Edge computing suggests that’s not the best way to do the job, because it costs money to upload lots of images to the cloud and it takes time for them to get there.
Edge computing therefore suggests that perhaps a Shelfie-using supermarket should operate a small server to do some basic analysis of the snaps the drone collects. For simple stuff with an immediate need like spotting an empty shelf, a small server has all the grunt a supermarket needs. For deeper analysis of which stock is shifting at which time of day and how to optimise the overall mix of products, it’s better to collect a day’s worth of snaps send them to the cloud to put 100, or 1,000, servers to work.
Another argument for Edge computing is that it allows pre-processing of data. To understand why, consider the flood of data that a large aircraft produces during the course of its flight. I keep being told it’s a terabyte or more.
Most of that data is dull telemetry. But if temperatures in Engine Four suddenly fluctuate a bit, analysis on the edge could be smart enough to realise that’s not something the crew needs to worry about but is something it’s worth sending to HQ ASAP.
A third application of the approach is to bring content and services closer to users, in ways that resemble an app store or a content delivery network.
The app store vision of edge is called “Network function virtualisation” (NFV) and is all about turning hardware into software.
Let’s again consider a supermarket that runs a Shelfie and imagine it needs to better protect the images it collects. Today that supermarket would buy a dedicated appliance called a firewall that does network security. Edge and NFV enthusiasts say they should instead download a firewall to the small server they run. That firewall would be functionally identical to a hardware firewall, but would take advantage of the special server’s unusually-strong networking features to make sure it can handle lots of traffic.
Telcos like this: they fancy being the operator of an app store full of virtual network functions their customers can buy or rent. They also fancy helping out with content distribution. To understand why, consider that today the likes of Netflix work with companies called Content Distribution Networks (CDNs) to pre-position to put lots of copies of video all around the world so that when a new series debuts and the world starts binge-watching, you and I only need to reach a nearby server instead of schlepping across the world on a submarine cable.
Today, CDNs sometimes rent space in phone exchanges or local data centres and put servers and storage there so that customers are closer to content. Edge computing suggests servers all over the place: on top of telephone poles, strapped to mobile phone towers, even bundled alongside broadband nodes (the latter two locations are prized because they already have power and fat backhaul links). When a hot new show comes out, a single copy could be put in servers near customers and the server could then transcode it on the fly in just the right format for your television. The video would travel meters on an uncontested link, rather than all the way to a bigger data centre or cloud.
None of what is described above is fanciful. Cisco makes a small server that’s ready for NFV, because it combines networking features and decent computing muscle. Dell and various startups are making servers and small data centres for outdoor use, leading to speculation about who will control the best sites for such kit. There’s also plenty of software can deliver content and software packaged to run on the edge. And that software is pretty mature because it’s been used to run big data centres and clouds for the last decade. Now it’s just running servers in more places.
Which is why none of this really threatens the cloud, because the Edge can be part of a cloud and/or will need to be orchestrated by something big and robust like – you guessed it – the cloud.
Simon Sharwood is the APAC editor of The Register and one of the country’s leading technology writers.