Network services, the problem statement (part 2)
In my recent post, “Network services, the problem statement,” I introduced the topic of what problem we’re trying to address with our new distributed software platform for deploying virtualized layer 4-7 network services, heleos. This series of blog posts was prompted by several discussions that started following the Embrane launch, particularly around the need for another architecture. In the post, I also touched on the decision those who deploy L4-7 network services in a data center deal with, the form factor to deploy and the tenancy options, as well as the notion that if you plot these two dimensions on a graph, you end up with 4 quadrants – each mapping to a number of metrics, including pricing and SLAs. Now I want to dive deeper into applying these quadrants to multi-tenancy options when it comes to the cloud.
Are we still living in the first quadrant?
Everybody wants the luxury experience of a spacious villa with a breathtaking view of the ocean (the first quadrant) at the price of a 1-bedroom roommate deal in an inconspicuous neighborhood (the fourth quadrant). And if enterprise IT is used to the comfort of the villa, they will hardly settle for the shared 1-bedroom, even if that’s what they really need. The twist of the 21st century is that now the enterprise customers are telling service providers “I’m tired of owning, I want to rent my villa from you, and I want to pay the rent only when I’m actually using the villa.” The service provider must make a compromise to avoid being crushed out of business: sharing the villa. Why not, after all, the villa had 20 rooms, 8 bathrooms and a huge sub-zero refrigerator; plus, the service provider says the tenants won’t bother one another. They’ll even have their private hallway to the bathroom (using VLANs, SDN, pick your flavor). The fine print is that the only cost structure that will prevent the service provider from going broke is to share the villa among 100 tenants. You get a bunk bed in a room you’re sharing with 4 more tenants; the room happens to be what had been originally designed as a wine cellar, but was repurposed to help increase density of tenancy; in other words, you don’t even get a window, if you were worried about missing out on the breathtaking view. Thank God the bathroom is very much nearby, reducing “latency” in case you really really need to get there quick, and don’t forget your private hallway! It’s just that you’re sharing the bathroom with 12 more tenants, so chances are that when you really really need to get there quick, someone will be already in there. Actually, probably there will also be a line of 3 or 4 people in front of you, all vehemently dancing in their private hallways waiting for their turn.
Welcome to the third quadrant of shared physical appliances! You get to brag with your friends that you live in a huge villa, but you’ll probably never invite them over. Hey, I remember a scene from “Doctor Zhivago” that was a bit like this (ok, some other time). But mind you, I’m not here to picture an evil service provider who’s making huge margins off your back, I’m describing the only reasonable way a service provider can offer you the villa experience at a reasonable price without going broke. The service provider is not having any fun: while you’re cursing in line to get to your morning shower (with 13 tenants per bathroom and 20 minutes per shower, you could have to wait up to 4 hours, so bring a book) the service provider is struggling to provide you with all the basic comforts that you used to take for granted. When the villa was built, nobody had thought to size the hot water and electricity for 100 tenants, so chances are your service provider is spending a lot of energies retrofitting and monitoring the villa’s water heaters to make sure your 4 hours wait won’t end up with a cold shower. The service provider is working hard to try to make your experience as comfortable as possible, but contrary to all expectations, the battleground is basic services, not plush pillows. Is this the SLA you were expecting?
Now think about the questions you asked when you started negotiating with your service provider the network services layer for your cloud. If you did like most do, your questions sounded a lot like: “Does the villa have a good view?” “Does it have granite countertops?” “Does it have a rain shower head in the master bath?” You’re not alone: the service provider probably asked the same questions when he started the adventure and purchased the villas. You (or your service provider) would have never asked “Do I get hot water for my shower?” or “How much shower time am I allotted?” The former are the right questions for the first quadrant, the latter, the right questions for the third quadrant. And while you can always upgrade yourself back to the first quadrant, it will cost you a pretty penny if the service provider has to buy a whole new villa just to rent it to you (how long are you going to stay anyway?).
Be sure that the network services vendors are not at fault for the situation either. They built villas for the first quadrant, and that someone would retrofit a villa to use it as a college dorm was probably not something they had expected. So, is the problem that the service provider should have bought a college dorm in the first place?