Facebook is back in the news again. This time, it’s because of the release of their new Wedge 100 switch into the Open Compute Project (OCP). Wedge was already making headlines when Facebook announced it two years ago. A fast, open sourced 40Gig Top-of-Rack (ToR) switch was huge. Now, Facebook is letting everyone in on the fun of a faster Wedge that has been deployed into production at Facebook data centers as well as being offered for sale through Edgecore Networks, which is itself a division of Accton. Accton has been leading the way in the whitebox switching market and Wedge 100 may be one of the ways it climbs to the top.
Wedge 100 is pretty impressive from the spec sheet. They paid special attention to making sure the modules were expandable, especially for faster CPUs and special purpose devices down the road. That’s possible because Wedge is a highly specialized micro server already. Rather than rearchitecting the guts of the whole thing, Facebook kept the CPU and the monitoring stack and just put newer, faster modules on it to ramp to 32x100Gig connectivity.
As suspected in the above image, Facebook is using Broadcom Tomahawk as the base connectivity in their switch, which isn’t surprising. Tomahawk is the roadmap for all vendors to get to 100Gig. It also means that the downlink connectivity for these switches could conceivably work in 25/50Gig increments. However, given the enormous amount of east/west traffic that Facebook must generate, Facebook has created a server platform they call Yosemite that has 100Gig links as well. Given the probably backplane there, you can imagine the data that’s getting thrown around the data centers.
That’s not all. Omar Baldonado has said that they are looking at going to 400Gig connectivity soon. That’s the kind of mind blowing speed that you see in places like Google and Facebook. Remember that this hardware is built for a specific purpose. They don’t just have elephant flows. They have flows the size of an elephant herd. That’s why they fret about the operating temperature of optics or the rack design they want to use (standard versus Open Racks). Because every little change matters a thousand fold at that scale.
Software For The People
The other exciting announcement from Facebook was on the software front. Of course, FBOSS has been updated to work with Wedge 100. I found it very interesting in the press release that much of the programming in FBOSS went into interoperability with Wedge 40 and with fixing the hardware side of things. This makes some sense when you realize that Facebook didn’t need to spend a lot of time making Wedge 40 interoperate with anything, since it was a wholesale replacement. But Wedge 100 would need to coexist with Wedge 40 as the rollout happens, so making everything play nice is a huge point on the checklist.
The other software announcement that got the community talking was support for third-party operating systems running on Wedge 100. The first one up was Open Network Linux from Big Switch Networks. ONL ran on the original Wedge 40 and now runs on the Wedge 100. This means that if you’re familiar with running BSN OSes on your devices, you can drop in a Wedge 100 in your spine or fabric and be ready to go.
The second exciting announcement about software comes from a new company, Apstra. Apstra announced their entry into OCP and their intent to get their Apstra Operating System (AOS) running on Wedge 100 by next year. That has a big potential impact for Apstra customers that want to deploy these switches down the road. I hope to hear more about this from Apstra during their presentation at Networking Field Day 13 next month.
Facebook is blazing a trail for fast ToR switches. They’ve got the technical chops to build what they need and release the designs to the rest of the world to be used for a variety of ideas. Granted, your data center looks nothing like Facebook. But the ideas they are pioneering are having an impact down the line. If Open Rack catches on you may see different ideas in data center standardization. If the Six Pack catches on as a new chassis concept, it’s going to change spines as well.
If you want to get your hands dirty with Wedge, build a new 100Gig pod and buy one from Edgecore. The downlinks can break out into 10Gig and 25Gig links for servers and knowing it can run ONL or Apstra AOS (eventually) gives you some familiar ground to start from. If it runs as fast as they say it does, it may be a better investment right now than waiting for Tomahawk II to come to your favorite vendor.