subject: The Way In Which Cloud Software Operates For Web Hosts [print this page] Cloud computing for a number of years has run sites like Facebook, Gmail, and Twitter. However, how it works is a mystery! Websites and applications run specific servers. But what makes cloud computing different is the way these are set up- the fact the cloud makes use of all resources from these computers and uses them as a collective. Forming in essence a giant virtual private server (VPS) and with the applications not running on any one particular set of servers. Thus individual pieces of hardware are not going to cause global failure. Of course in reality it is not a VPS, but a cloud. With people using high speed internet these days, the need to have software running locally is becoming less and less. Many applications are already web based like Google Docs, the cloud engine take these to the next level. Behind the scenes companies have been making the move to cloud software, without realising. We have been using office type software for years now- and this works readily via Google Docs. Although of course you are always at the mercy of the online software and your internet connection. Cloud software comprises of multiple layers- backend and front end. Take Twitter for example where you are interacting with the software hosted on these front end layers. The back end normally refers to the hardware level. The back end of a cloud is powered from multiple servers, with multiple cores and plenty of RAM. These are controlled by a control node or a hypervisor that controls the servers in the cloud. There will then be a some form of storage typically a SAN (storage area network) which will hold all the data used by users and will also then have a backup for redundancy. Cloud setups with this level of sophistication normally cost tens of thousands to setup. Cloud software runs on its own, then powers the front end software in front of it. These will then have the applications needed to present the data to the user installed on. So a web based application would need Apache, MySQL and other such tools. This is no different to using a popular website such as Facebook.
