Some of the news bits I saw this week raised an interesting point (to me, at least), which is that they reflected an underlying point that was being overlooked. So I want to look at them today, and ask “Why is it…..?”
The top item is that big Netflix outage over the holidays. Everyone knows that Amazon’s cloud hosts Netflix, and everyone knows that the cloud is supposed to be the ultimate step forward in reliability/availability? Why is it that we have such radical cloud failures if that’s the case? Here again we have two answers.
Top of the hit parade, answer-wise is that the cloud isn’t intrinsically more reliable. The general truth in “reliability” is that anything is as reliable as its least-reliable component. Cloud technology that is going to provide for automatic augmentation of resources when loads peak will depend on its resource-allocation process. Is that a device or computer? Is it “redundant?” How can you make the thing that’s supposed to recognize load issues and respond immune to loading or failure? It’s possible I guess, but we really don’t pay enough attention to the architectural elements of a cloud computing deployment so we truthfully don’t have any notion of what its real availability model would look like.
The second point is that performance of any sort costs. Again, we have a misconception about the cloud, which is that the public cloud is always cheaper. Not true. The public cloud is cheaper just as hosting web servers is cheaper—when resources are under-utilized. Operating at a large scale, enterprises or media companies can deliver similar economies of scale, and that means that companies like Netflix are having to push the economics of their hosting relationship to be profitable and keep Wall Street happy. So do they buy the most reliable stuff? Do you, in your own business, protect yourself absolutely against failures, or do you roll the dice just a bit? The latter is what nearly every enterprise does, and likely what Netflix does. You get what you pay for.
Then we have an SDN question. When we read about SDN we almost always read in terms of “it’s OpenFlow” or “it’s proprietary” as the polar alternatives. Why is it that we have framed a concept as general as “software defined networking” into such an explicit implementation framework as OpenFlow, particularly given that OpenFlow isn’t sufficient to create an SDN to start with? Guess what; two answers.
First, you can’t underestimate the role of the media here. “News” means “novelty”, it doesn’t mean “truth” (for you cynics, “Pravda” means “truth”). The press is an industry with its own priorities, generating clicks on URLs to serve ads that pay to keep the lights on. There are a limited number of reporter-hours available to push material out, and if you want the most clicks you push the most “readable” material, not necessarily the most relevant or useful. In the SDN space, the promise of a complete network revolution is more “readable” than the truth that we have to evolve to SDN or everyone has to toss their gear and start over. But that’s a network evolution story, and evolution takes millions of years in biology. It might as well take that long in technology, from a press perspective, because nobody is going to read through the dry details.
The second point is that nobody understands what’s inside an SDN to start with. I pointed out yesterday that buyers wouldn’t be able to draw a complete diagram of SDN that had more than two boxes; “software” and “network”, which is hardly dazzling insight. So if we don’t understand the functional elements of an SDN, how can we understand what these elements map to in terms of standards or protocols or even products? There is every chance that what will emerge as an “SDN” architecture will be a combination of OpenFlow, the Policy Charging and Control framework of mobile/3GPP, and Network Functions Virtualization. Until we understand how those things relate to individual functional boxes, though, we can’t make much progress. And absent reality, a good fable is enough to drive the media coverage.
We’re at the root of the problem here, though. There is no reason why all of the points I’ve noted here couldn’t be fixed in a heartbeat. All that’s needed is to face reality. Shall we give that a try for the new year?