Number 319 - December 2009

The web designers' guide to cloud hosting All you need to know about developing and hosting in the cloud
by Tim Carr
Part 1: Hosting on the cloud    Cloud computing is quietly taking over the world and changing the way we use our computers forever. Whether you're storing your photo collection on Flickr or logging on to Gmail, everyone's now using the cloud, even if they don't realise it. But how does it work and how can we as web designers and developers make it work for us?    Cloud computing runs on virtual servers. Rather than being a single physical box, a virtual server runs as part of a physical box. This type of virtualisation is nothing new and has long been a cost-effective entry-level solution. Virtual machines on the cloud run on clusters of servers. Again, this is nothing new: most medium-to-large server set-ups involve clustering. Hardware as a service    The big difference with cloud hosting is that it packages all of this up so that it's 'Hardware as a Service' - the clustering, virtualisation and resilience are all a given. The virtual server on the cloud runs across many thousands of servers, in different data centres in different locations: an entire 'cloud' of servers.    In terms of server architecture, this looks like an obvious progression. In terms of users, developers and business, the implications are as big as the cloud itself.    The move to cloud hosting requires a shift in mindset similar to that when stepping away from apps stored on your own machine to those managed on the web. In the same way that Google Docs means you no longer have to install Microsoft Word, and Spotify means you can listen to music without downloading it from iTunes, with cloud hosting there's no longer a need to lease a server: you can use as much or as little as you need. Hosting on the cloud    The big player bringing cloud hosting to the masses is Amazon Web Services (AWS), and its timing couldn't be better. Economically, we're living in uncertain times. When it comes to upgrading a 12-month hosting contract or trying to justify another capital expenditure in terms of new hardware, painful decisions need to be made. But with cloud computing, there's less need to worry.    Because you pay for what you use, rather than having to buy upfront what you think you only might use, cloud hosting provides the ultimate pay-as-you go hosting solution. Rather than compromise on performance or scalability, you can just host on the cloud.    As Amazon's CTO, Werner Vogels, put it: "Anything is crappy, whether it's your hardware, your network, your operating system. Don't let anyone tell you that this stuff is unbreakable; if you have enough of these things sitting around, they all break all the time." This is the philosophy with which the Amazon infrastructure has been set up.    As such, AWS cloud hosting is set up over 19 different data centres globally, each with different power connectivity, internet connectivity and geographical location. What happens if one of these data centres goes down? Well, they do go down all of the time: Amazon pulls the plug on one of its data centres monthly, as a real-life rehearsal of what would happen in a fire. Hosting security evolves    In the old days, many a CTO used to think that the safest place to keep a server was in the office: that way, security could be ensured by fixing the latest in window locks and alarms and ensuring the night security guard had enough coffee. Of course, this approach was about as resilient as keeping your hard-earned cash under the floorboards.    The next approach to hosting security was to put your server in a data centre, with managed security and support. This approach has proved sufficient for many, but it's as limiting as putting all your money in a bank. And as we've all become aware recently, having all of your savings in one bank is something to be discouraged - if it goes down, so does your business.    Now imagine putting each one of your pounds (or dollars - ed) into a different bank account. If you did, then should one of the banks fail, you'd carry on as normal. The same can be said for cloud hosting.    Developing on the cloud    At 3ev , we approach cloud hosting with enthusiasm, because essentially it enables our techies to get their hands on as many servers at any one time as they like.    Previously, we had a couple of collocated live servers for all of our hosting requirements, and setting up an additional box to test something out on was painful, both in terms of expense and time. Additionally there was a certain level of commitment involved: we'd have had to have that server for a minimum of a month, when often we'd just want to set something up for an afternoon.    Nowadays, on the cloud, the virtual machines look just like normal servers. You can sign in, move stuff around and even install software. So what's actually different?	First, it's brilliantly easy to take snapshots. You can take a snapshot of your data at any time you like and, because you can buy as much storage space as your requirements dictate, you can just keep going. Working with this level of agility means that if one of your sites needs some immediate and risky maintenance, this is easier than ever before.    You can instantly clone it onto a new server - and work on the clone - in the "live" environment. With the cloud you always have spare servers sitting around, should you need them.    Part 2: Scaling on demand    If your app or site hasn't been on larger infrastructures before, you'll need to make sure it can scale well. Dedicated hosting tends to encourage coders to build for a fixed number of machines, but cloud hosting needs a more scalable approach. If you're scaling on demand, the number of machines can shrink and grow automatically, so your app needs to be able to cope with this from the ground up.    This is a big area, so the best approach is to fire up a few instances on EC2 and find out whether it scales. It's possible to rehearse for any eventuality, which is useful when running sites and apps prone to spikes in traffic. Test instead of guess.    This ability to rapidly scale your application and have the privilege to instantly throw dozens of servers at a problem aren't things that anyone had the luxury of until cloud computing became available.    The cost of scaling at short notice is also surprisingly cheap. Amazon provides backup onto the cloud through its S3 service (Secure simple storage). Rather than backing up your data once, S3 makes six copies, all in different locations on different hard disks. S3 can be combined with EC2, meaning that you can turn servers on and off with unprecedented ease and can cater for any eventuality, both planned and unforeseen.    Cloud hosting makes it entirely possible for serious e-business to be within reach of any developer with ideas. The set-up cost of a cloud server running on Amazon is 10 cents plus a valid credit card. From this initial set-up, you can scale up to running many, many different instances of the server - with no additional lead time or further contracts to delay the process. Benefits to business    The implications of this are already benefiting a large number of businesses that, without this low cost of entry, simply wouldn't exist. For instance, in December 2007 the social networking games company Playfish launched a game called "Who Has The Biggest Brain?"    Since then Playfish has grown exponentially. It's currently responsible for most of the top ten games on Facebook and provides games to more than 50 million users. Scaling an operation such as this using a traditional set-up would have been prohibitively expensive and unreliable. With user numbers increasing by up to one million in the space of 24 hours, there would have been moments of poor service and downtime where the infrastructure just couldn't cope. Not only did cloud hosting make the initial outlay affordable, it made the entire solution more agile and made scaling more responsive.    The traditional way of scaling often either overcaters or under-caters for demand. The lead times involved in setting up, getting the capital expenditure authorised, even configuring the new boxes the same as the existing ones, all introduce unnecessary delay. It's a constant game of cat and mouse between demand and capacity. Coping with demand    With cloud hosting, you don't need to worry about any of that. A new server can be powered up in a matter of minutes and configured exactly the same as your existing one using a simple configuration tool. Similarly, if your demand falls off, you can turn these extra boxes off as easily as you turned them on. Cloud computing takes the infrastructure and scaling costs out of professional hosting.    As such, the ground is fertile for new web ideas that previously just wouldn't have been possible. Just like open source software, cloud hosting reduces the cost of failure. Everything (is run) as a service(:) With storage, backups, music and even operating systems such as GOs (thinkgos.com) being run as a service, personal computers will become smaller, lower spec and ultimately cheaper.    There's less for them to do, as everything is done on the cloud. This phenomenon is known as thin-client computing - we'll able to run all of the apps we currently run on our laptops and PCs on the cloud. Gartner has predicted that worldwide netbook sales will grow from just over 5million in 2008 to 7.8million in 2009. That's more than 50 per cent growth, compared to a predicted 15 per cent growth for the entire laptop market and an overall decline in sales for desktop PCs.    Music need no longer take up bags of valuable space on your hard drive. Ownership is old hat. Run your digital life as a service. There's just no escaping the cloud!
Number 319 - December 2009