Vineet Gupta

As a kid, I found studies quite boring. (who doesn't?) The first subject I fell in love was Physics (actually second - first one was Computer Science) I used to find it utterly boring too, but this changed when I was in 11th standard and was forced to stay at home for about two months because of a strong bout of Juvenile idiopathic arthritis in my knees. I missed out on the first-term exams because of this and the fear of not doing well in the mid-term made me start studying my weakest subject - Physics. That is when I realized the beauty of Physics - it made me see the world around me differently. That love affair continues till today.

After I started working, I also started developing a love for Evolution, Anthropology, History and Economics as well - they made me look at the world around me in a different way. And this world is full of wonder and beauty. I wish I could go back to school now and find the time to study all of them at leisure. I think the problem with our education system is that instead of letting kids understand these wonderful views of our world on their own, at their own pace, they emphasize on spoon feeding the details of each view. You miss out on all the fun in the process.

So for the last five years or so (I recall telling my wife about this when I first met her more than four years ago) I have been thinking about writing down the story of our world in a simple, easy to understand way which emphasizes the big picture and connects the dots. I finally started writing some early thoughts a couple of weeks back and the result is a new blog: http://bigtale.blogspot.com/. I'm having a ton of fun writing this and hope that it serves as a useful resource to anyone who wants to know more about our world.

For about 2-3 years now, I have been talking internally in my group and to other people in Microsoft on Edge Computing vs. Cloud Computing. This thing came up all over again in a discussion and I thought it would be handy to summarize my thoughts in writing somewhere.

Terminology

The way I use the terms Cloud and Edge are not common to the industry (are there common industry definitions on this at all?), so let's just put this down first:

1) Cloud Computing is computing that happens in distributed, geo-plexed infrastructures on the Internet. Amazon Web Services and Google App Engine are examples of general purpose Cloud infrastructures. You can call it off-premise computing as well. The idea is that instead of creating your own facility, or putting your server with a hoster, you put your data / apps in a Cloud. This cloud is assumed to have 100% availability, and infinite scalability. This is typically achieved in two ways:

a) Virtual machine hosting service - The advantage is that you can bring in any existing workload, virtualize it and host it. No changes required to your app architecture. For example Amazon EC2 provides Xen virtualization. However, this is not very elastic in the sense that the computing power is handed out in discrete units of virtual private servers and there is no continuous scaling. The underlying fabric may have infinite continuous scaling but the way it is handed out is discretized.

b) Abstracted Infra for Prescriptive Services - This approach is where the Cloud vendor offers specific services for data storage, communication, app execution, etc. For example Google AppEngine provides data storage, user management and an app execution environment based on Python. Similarly, Amazon provides a storage service (S3), a message queue (SQS) and a structured storage service (SimpleDB). Microsoft has also announced a couple of services: BizTalk Services for hosted message oriented communications and SQL Server Data Services which aims to provide SQL Server functionality in the Cloud. IBM announced Blue Cloud in Nov, but haven't released much info on it since then. The key thing here is that these services themselves are infinitely scalable, and this means that apps built to these services are also elastically scalable. Of course billing may happen in price bands based on consumption, but the app itself is not boxed.

2) Edge Computing is computing that happens outside the Cloud. This could be on a hand-held device, on a PC, on a server in a data-center. For the server scenario, this could be hosted on premise, or this could be in a hoster's datacenter. The key thing is that this is not distributed, geo-plexed, on-demand scaling in the Cloud. The computing is contained in isolated boxes that may / may not talk to each other.

Now the hosting scenario is a bit of an overlap - when does an app hosted with a hoster stop being Edge and become Cloud? To me the key difference is distribution because it is distribution that provides 100% availability and scalability. If you place your server with a hoster, if that hoster's datacenter goes down, your server is down. This is Edge. If you place your app / data with a hoster that has got a distributed infrastructure, is able to move load from datacenter to datacenter based on traffic conditions and lets you take unlimited load - it is Cloud.

Now with that out of the way, let's get down to examining the trends and see which model is likely to succeed.

A Lesson in Computing History 

If you go back a few decades in time, computing was primarily driven by governments, and specifically defense establishments or research agencies. Then something happened in 1946 - scientists working for a US government agency came up with the first general purpose computer – the ENIAC. The impact of this development was that computing moved from being solely owned by a few governments in the world, to becoming affordable to businesses. And even then, only some of the richest businesses – the largest banks or manufacturing companies – could afford to buy computing power. Over a period of time, computing got cheaper and more and more businesses were able to use the power of the computer. For the next two decades, well into the 1970s, all computing was business computing or special-purpose government / scientific computing

The second revolution in computing came when Kilby and Noyce independently came up with the Integrated Circuit, which was used by Ted Hoff and Federico Faggin at Intel to develop the Microprocessor. A couple of smart people – Steve Wozniac, Bill Gates, Paul Allen - figured that this meant that computing power cost was to drop in a non-linear way, and would become affordable to consumers. This eventually led to the PC.

The first personal computer – the Altair 8800 -  when it came out in 1975, was targeted at the uber-geek of the day – the computer enthusiast! This would probably not have become a mainstay had it not been for a program called the VisiCalc spreadsheet. VisiCalc was the predecessor to the Lotus Spreadsheet which in turn preceded Microsoft Excel.  VisiCalc was what propelled the PC into business computing.  Businesses started buying PCs so that their finance people could run VisiCalc. This mass purchasing in turn brought down prices which in turn led to more consumption, both on the business computing and the personal computing front, which spurred more innovation and more price falls. A virtuous cycle got started, and for the first time we saw the growth of a segment called personal computing.

However, personal computing would perhaps have remained small had it not been for a phenomenon which caught almost everybody unawares – the World Wide Web. When Berners Lee invented the hyper-text at CERN in 1990 to solve the problem of navigating thru complex documentation, no one realized that it would enable hyper linking on a global scale, making everyone with a connection to the Internet a publisher with a planet-wide audience.

To summarize, the 1950s saw computing move from the domain of a few governments to becoming available to businesses – business computing was born. The 70s saw the birth of personal computing. The 90s saw the WWW which led to huge growth in personal computing as well as business computing. Every 20 years, the industry witnesses a revolution of sorts. It is almost 20 years since the last one. What’s next?

Industry Trends

One of the truest trends in the industry has been Moore’s Law - it has held true for the last 40 years – computing power is still doubling every 18 months or so. Differently put, computing power prices are still dropping non-linearly after four decades. Incidentally price of storage has also been falling non-linearly. The only major component which does not obey this law is bandwidth where price falls seem to be linear. I have outlined the hardware trends in a couple of earlier posts as well, you may want to go thru them for more context.

Second, the mobile phone has put enormous computing power in the hands of ev