Welcome. In this, uh, lecture series, uh, we'll be looking at, uh, an introduction to cloud computing, and we'll focus a little bit on, uh, the aspects that distinguish, uh, cloud computing from previous generations of, uh, distributed, uh, systems. So, uh, first of all there's a lot of hype around cloud computing. Uh, several, uh, forecasting agencies which, uh, forecast mark-market trends for different, uh, markets have said that cloud computing is large and it's only going to grow, uh, perhaps exponentially. Gartner, which is one of the most, uh, popular forecasting firms, said in 2009 that cloud computing revenue would exceed $150 billion by 2013, and that it would represent a significant fraction of IT spending, uh, by 2015. IDC in 2009 said that, uh, in, um, the, uh, next 5 years, uh, spending on IT cloud services would triple and would reach several tens of billions of dollars. Forrester said that cloud computing would go to $240 billion as an industry by 2020. And it's not just in industry. Several governments have also started relying on cloud computing, including fedbizopps.gov, which was set up, uh, set up many, uh, years ago by the federal, uh, government. So obviously there is a lot of hype, uh, but then the question is what exactly is cloud computing? Well, there are many cloud providers, as I'm sure, uh, many of you, uh, might have heard of. One of the most, uh, popular cloud providers is AWS, or Amazon Web Services. There are also other, uh, providers here, Microsoft Azure, uh, Google Compute Engine, and there are a whole bunch of other companies, including Rightscale, Salesforce, EMC, Gigaspaces, 10gen, Datastax, Oracle, VMWare, Yahoo, Cloudera, and hundreds of more companies that are too many to, uh, mention here. So let's just focus on the, um, uh, AWS, uh, portion. Uh, AWS offers a variety of services; three of their most popular services are called EC2, S3 and EBS. EC2 is an elastic compute cloud, which provides the computing services, S3 is a simple storage service, which provides you the ability to store data so that you can access it from anywhere in the world, and EBS is Elastic Block Storage, which is essentially volume storage that the EC2 instances can access while they are running. So there're two categories of clouds, uh, today. Uh, they are either public cloud or a private cloud. A private cloud is one that is accessible only to, uh, special privileged employees or personnel. For instance, if you're working in a company X, and the company X has a data center or a cluster or a cloud which is accessible only to the employees of the company, that's a private cloud; it is not openly accessible. On the other hand, uh, a-a public cloud is one that can be accessed by anyone, anywhere in the world, as long as they have a credit card and are willing to pay. Uh, private clouds, for instance, also include, uh, the first category also includes, uh, you buying a data center or a cloud and running it yourself; that's your own private cloud, obviously. So among public clouds, the ones that are openly accessible, uh, um, as I mentioned, uh, there are a couple that are, uh, fairly popular, Amazon AWS services, uh, Google Compute Engine, and, uh, the, uh, Microsoft Azure tend to be popular. Uh, the AWS and Azure share a lot of, uh, traits, so I'll just focus on AWS here. Uh, the S3 Simple Storage Service allows you to store arbitrary data sets, and you pay per gigabyte month that you store; there are no upfront costs. The Elastic Compute Cloud, uh, once again allows you to upload and run arbitrary OS images. Essentially they are- these are virtual machines, or VMs, and you pay per CPU hours that you use. So if you use, say, 5 VMs for 1 hour, uh, each, all at the same time, you'd be paying, uh, for 5 CPU hours. And similarly, the other services that, uh, AWS or Microsoft Azure might offer, uh, are also, uh, priced accordingly. Uh, there are a variants of this of course. Google AppEngine or Compute Engine offers the ability to develop applications within, uh, their AppEngine, uh, and then you upload the data that would be imported into their format, and you run your application. So for instance, you could use these to host your own web services, you could use these, um, to host your, uh, data so that it is served out, or you could host these to run your own computation, uh, that you might want to run. So, cloud computing is attractive to customers because, uh, it allows them to save both time as well as money. Uh, Eli Lilly, which is one of the largest, uh, um, customers of AWS, reputedly, uh, for instance, uh, er, uh, has been, uh, benefiting from the ability to bring up new servers fairly quickly. Earlier they reported that it used to take, uh, seven and a half weeks for them to deploy a new server. This would, uh, involve, uh, them, uh, um, uh, uh, setting the specs for the server, then actually purchasing it, and then going through the purchasing process, uh, the server comes in and they set it up, uh, and install the necessary s- operating system and software, and all of this takes, uh, took several weeks. Now they can rig up a new server in, uh, around 3 minutes, and a 64-node Linux cluster in 5 minutes, uh, while it was taking months, uh, earlier. This of course saves them time; it also saves them money, because, uh, they can save the costs that they might have otherwise had to pay the sysadmins. GlaxoSmithKline reported that, uh, they saved about 30% by moving to the cloud. Uh, Jim Swartz, uh, from CI- the CIO Sybase said that, uh, they've been saving $2 million since 2006, and this is only going to increase. And as a result, it's not surprising that hundreds of startups across Silicon Valley, uh, are leveraging, uh, some of the cloud providers, who I mentioned, and a variety of other cloud providers as well, rather than buying their own machines. But once again, this brings us back to the question of what exactly is a cloud for us, uh, technical folks, who want to understand the deep, detailed, uh, aspects of cloud computing. We'll discuss that in, uh, the next lecture. [electronic music]
