Monday Jun 08, 2009

Virtual chassis or big core switch?

We're building out our next generation infrastructure, and we're upgrading critical parts of our infrastructure to 10GBe. One of the things we've been debating is whether to use a big core switch or take advantage of some of the virtual chassis technologies that are now available (clustering many smaller switches to look like a big chassis switch).

We're well on our way to proving out the virtual chassis technology from Juniper. It fits our data flow rates, and it's easy to manage. Over time, we've put in network gear from several vendors. This was good as we used the best from each vendor. The problem is that it causes a maintenance hassle. Your engineers have to know 2 or 3 command sets, and that's a problem. So now we're moving towards standardizing on one or two vendors to simplify maintenance.

It turns out that we realized several things about our rack layouts. We always have limited space, so we typically laid our systems into the racks on an as-needed basis. We would find the right amount of space, make sure we had enough power and just dump the systems in as we could (splitting the systems so no one service was in a single rack/row, etc.)

Our next generation design takes into account data providers and data consumers, making sure that they connect via high bandwidth connections. Our front-ends (data consumers) don't typically consume more than 1gb connections to the backends (data providers), but if you get several front-ends talking to one backend, and the backend is on a 1gb link to the top-of-rack switch, you can get into some serious problems. We're able to work around that on our very high bandwidth backends by trunking connections, but even then it's suboptimal. So we're going to make sure we have 10g connections to the backends, and that we keep the number of "all-10g" racks to a minimum (to keep costs under control). Our rack layouts will definitely change, focusing on high availability, very high performance while staying in our power constraints.

I'll talk more (probably) in a future blog about the other things we're doing in the network.

Driving to Manteca

I had to drive to Manteca this morning. "Why?", you wonder? Well, I have 2 greyhounds. They're the sweetest dogs in the world - just the best dogs. But they're fragile. And they tend to break or injure their legs.

I managed to rescue two dogs that are incredible, but have needed a little extra care here and there. Max (maximum speed) is a white with brindle patches gigantic (75lbs) male. He's got a little problem with an osteoma on his right front leg. Just figuring that out cost me over $1000 at the local animal hospital. And we still don't know what it really is. We finally took him to a orthopedic surgeon that specializes in greyhounds. Of course, he's located in Manteca. Which if you don't know your california cities, is about 90 minutes from menlo park. If you're lucky. Max was on bed rest and such for 4 weeks - he's doing much better thanks.

And so of course, Max gets better, so we take him and Molly (a dark brindle) to the park to run. Molly is an italian sports car to Max's american musclecar. She's light (50lbs) and very, very fast. She was trained as a spoiler (she spoils the really fast dog's racing by nipping at their backs). The dogs took off in the dog run, and because it's been a while, they go from 0 to full speed in about a second flat. Things are fine for the first 3 minutes, and then Molly barks and starts whining in a "umm, something is wrong" kind of way. Great. She broke her ankle - technically dislocated her central metatarsal.

So that's why I drove to Manteca this morning. To see the specialist.

On the way home I was really surprised by the quality of driving along the 580 corridor. It was scary - and I don't get scared driving. I learned how to drive in Los Angeles. Doing 80mph 10 feet off the next guys' bumper is old hat to me. And I have a pro racing license (well, it's probably expired by now, but I had one). Anyway, I'm driving along and people are slicing and dicing at 80mph - slotting through the 10ft gaps. With semi's playing just to keep things interesting. At least twice I actually slammed on my brakes and prayed a lot that the guy behind me on his cell (with no headset of course) was paying attention at exactly that moment. I'd have been in the slow lane at a mere 75, but that was the Lane of Death with all the semi-trucks dicing in and out. All in all, kinda fun, but weird as I can't quite figure out what the hurry was all about. Does everyone start work at 10am? (note: I was on my hands-free in 3 separate meetings for the drive out and back)


I run the engineering group responsible for and the high volume websites at Sun.

Will Snow
Sr. Engineering Director


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