Cloud computing is still in its early days, adaptation is yet to become widespread, but we can foresee a future where Cloud computing would become a mainstream computing platform to save deployment and environmental hazards.

If you understand, what is a Grid and Grid Computing, then understanding Cloud becomes easy. Grid is essentially a Cluster of computers coupled loosely with each other. Loosely coupled mean whose interconnect is either not 100% available or the latency of interconnect is high. The prime job of a grid is to share a distributed job load and process it aggregately.

An example for Grids is the SETI@Home (a.k.a search for extraterrestrial intelligence at Home), where the data captured by the SETI radio telescope is distributed across the globe to millions of home PCs so that the job can utilize the PC's free processing time and process the data and send it back. This is a good example to understand a Grid in action.

Deploying any virtualization architecture on top of the grid and you get a Cloud. In this case, the grid nodes are not so loosely coupled and managed inside a data-center. Aggregating and consolidating the computing resources under one single grid platform and deploying a virtualization platform on top of it makes easy to cut a slice of the grid into the desired configuration and provide it to the user as and when required. This is the main benefit of cloud computing.

So, let's suppose a pool of 400 processing cores and 800 GB of RAM is present in a Grid, it makes easy to pull out a virtual slice of let's say 16 cores and 16 GB of RAM at any point of time and provide it to a user who requires it. Once the work is complete or if the resources are not utilized at a particular point, the resources go and merge back to the almighty Cloud and are utilized for some other purpose.

Now SOA (Service Oriented Architecture), software services is a methodology of yesteryear. Cloud computing, infrastructure services are taking the limelight now. Users are no way bothered about the services required, all present and only have to pay for the services required. The architecture of both services is more or less the same.

Using cloud computing, one has to take care of the business data, which goes to the service provider services and infrastructure. Any downtime at the service provider will affect the business.

Written on 16th October 2008

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