On a recent teach of the Learning Tree Cloud Computing course, I was asked about the difference between Grid Computing and Cloud Computing. An excellent question, because there are similarities between the two but also differences. Lets consider these individually.
Starting with Grid computing. A grid comprises of a set of loosely coupled computers that are networked together and form what appears a single coherent whole. The magic that makes this integration happen is middleware software that manages the computers, detects failures, new computers being added and computers being removed from the logical grid. Using the middleware software, applications can be deployed to the grid and they will use whatever cpu utilisation and storage the grid can provide them for their current demands. For compute intensive tasks, the more computers in the grid the faster the tasks will complete. Grids are often on-premise and dedicated to an individual organisation or project.
Now consider Cloud Computing, which provides three levels of service. At one end is Software as a Service (SaaS), allowing a pay per use model to be applied to acquiring software with no on-premise hosting. Platform as a Service (PaaS) provides an elastically scalable compute platform including middleware for applications to be deployed to. Finally Infrastructure as a Service (IaaS) enables servers, storage, networks to be provisioned on demand and on a pay as you use basis with self administration of the infrastructure.
Comparing the two
Comparing Grid with the Cloud Computing services, Grid computing most closely compares with PaaS in Cloud Computing. It provides a deployment environment for application software which will elastically scale its compute and storage capacity to best meet the applications immediate requirements, all autonomously. A grid may be considered as a private cloud delivering PaaS. There are however, a lot of differences between Grid and Cloud computing including:
Grids are normally on-premise, and owned by an organisation, whereas clouds are normally provided by vendors and utilised on an as needs, pay per use basis by many different organisations. Grids do not provide the ability to individually provision servers and the self administration including installing a variety of operating system and software applications on these servers like IaaS does.
In summary, Grid computing and Cloud computing have some similarities: scalable, on demand compute and storage. They also have some major differences: immediate self provisioning, pay per use and a wide variety of applications available via the cloud.
If you are interested in learning how you can maybe leverage Cloud Computing for your organisation, why not consider attending the Cloud Computing course. We explore in detail and provide hands-on exposure to a variety of Cloud Computing services, considering the benefits and risks of adopting these for your organisation.