Cloud computing makes a massive amount of horizontal scalability available to applications that can take advantage of it. The trend toward designing and refactoring applications to work well in horizontally scaled environments means that an increasing number of applications are well suited to cloud computing.
Applications taking advantage of horizontal scaling should focus on overall application availability with the assumption that individual components will fail. Most cloud platforms are built on a virtual pool of server resources where, if any one physical server fails, the virtual machines that it was hosting are simply restarted on a different physical server. The combination of stateless and loose-coupled application components with horizontal scaling promotes a fail-in-place strategy that does not depend on the reliability of any one component.
Horizontal scaling does not have to be limited to a single cloud. Depending on the size and location of application data, “surge computing” can be used to extend a cloud’s capability to accommodate temporary increases in workload. In surge computing, an application running in a private cloud might recruit additional resources from a public cloud as the need arises.
Surge computing depends heavily on the amount and locality of data. In the case of a private cloud located in an enterprise datacenter expanding to use a public cloud located somewhere else on the Internet, the amount of data that needs to be moved onto the public cloud needs to be factored in to the equation. In the case of a private cloud hosted at the same colocation facility as a public cloud provider, the data locality issue is significantly diminished because virtually unlimited, free bandwidth can connect the two clouds.
Source of Information : Introduction to Cloud Computing architecture White Paper 1st Edition, June 2009
Applications taking advantage of horizontal scaling should focus on overall application availability with the assumption that individual components will fail. Most cloud platforms are built on a virtual pool of server resources where, if any one physical server fails, the virtual machines that it was hosting are simply restarted on a different physical server. The combination of stateless and loose-coupled application components with horizontal scaling promotes a fail-in-place strategy that does not depend on the reliability of any one component.
Horizontal scaling does not have to be limited to a single cloud. Depending on the size and location of application data, “surge computing” can be used to extend a cloud’s capability to accommodate temporary increases in workload. In surge computing, an application running in a private cloud might recruit additional resources from a public cloud as the need arises.
Surge computing depends heavily on the amount and locality of data. In the case of a private cloud located in an enterprise datacenter expanding to use a public cloud located somewhere else on the Internet, the amount of data that needs to be moved onto the public cloud needs to be factored in to the equation. In the case of a private cloud hosted at the same colocation facility as a public cloud provider, the data locality issue is significantly diminished because virtually unlimited, free bandwidth can connect the two clouds.
Source of Information : Introduction to Cloud Computing architecture White Paper 1st Edition, June 2009
|
|
0 comments
Post a Comment