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Cloud computing consists of hardware and software services from a provider on the Internet (the “cloud”). Cloud providers replace in-house operations and are invaluable for companies, no matter the size, or what kind of applications they have. Currently, cloud computers consists of servers thatone can configure to handle tiny or huge amounts of traffic and expand or contract as needed. This eliminates the security, maintenance, network and environmental issues with home grown datacenters. For the in-house version of cloud computing, see intranet.
Not every internet function exists as cloud computing. Cloud computing refers to any service available online, such as websites, email, automatic updates, backup, photo storage, and streaming. The Internet is the biggest network in the world, so virtually anything that is available online could be considered cloud computing. However, technically, cloud computing comprises the following two services, which replace software installed in the user’s computer with online access. See cloud.
In the beginning, cloud computing started with software as a service (SaaS), which offers online business applications by subscription. The cloud provider manages everything and accessed online via the Web browser. The web browser the only application required in the user’s machine.
Secondly, tech giants such as Amazon, Google and Microsoft, with years of experience running huge datacenters, began to rent time on their servers, allowing companies a viable alternative to housing their own. Amazon is the largest. See Amazon Web Services, Google App Engine and Windows Azure.
(Self Service) The customer sets up an account online and manages the process from start to finish.
(Scalability) Both users and servers can be easily added and deleted.
(Speed and Reliability) Multiple cloud datacenters and network backbones provide fast response times and fault tolerance.
After the Web became popular in the late 1990s, for the first time, SaaS providers offered business applications to the end user online, eliminating routine and error-prone in-house software maintenance. Salesforce.com was notably one of the first. Customers pay by the number of users. For the IT department, this became a paradigm shift. However, every solution generates other problems. With data stored outside the company, there are security and privacy issues.
Also called “cloud hosting” and “utility computing.” IaaS provides the bare server hardware, or the hardware plus a virtual machine (VM), The VM rwsidesin one partition in a server shared by many customers. IaaS customers upload all the software, from OS to applications. See virtual machine and software stack.
PaaS includes the server hardware, operating system and database, plus all necessary system software to run applications (the “stack”). With IaaS and PaaS, customers pay by some combination of server size, speed, storage capacity and network time (uploads and downloads). See stack, runtime engine and system software.
FaaS includes the server hardware at the most granular level. FaaS customers pay only for the time it takes to execute specific tasks (see serverless computing).
Cloud datacenters employ server virtualization, which, among other benefits, allows workloads to be added and removed as self-contained modules. Customers who use IaaS and PaaS require technical skills to configure these functions. Without virtualization becoming mainstream in the IT world, cloud computing would not have emerged. See server virtualization and virtual machine.
Enterprises can create private clouds in their datacenters that employ the same cloud computing infrastructure used on the Internet. The private cloud provides the same flexibility and self-service capabilities, but with control of privacy.
A hybrid cloud is a combination of both private and public. Companies may decide to keep certain applications in-house while deploying others to the cloud. In addition, if the private cloud becomes overloaded, users can activateapplications temporarily on the Internet cloud; for example, during the holidays for an e-commerce website.
Managing both internal servers and providers’ servers from a central console are major issues in cloud computing administration. See private cloud, fog computing, cloud management system, multicloud, personal cloud, Windows Azure, thin client, cloud storage, colocation, Open Cloud Manifesto and Web application.
