As a first step, organizations have to identify which applications in the portfolio would benefit from moving to the cloud. One has to subject all the applications to a detailed analysis on its suitability to move to cloud. These are the usage and load pattern of the applications, clustering of applications based on integration, business benefit, and capex/ opex analysis.
An income tax details submission application in an enterprise does not have a uniform usage across all 365 days of the year. The usage peaks during the end of financial year (particularly for a fortnight) when all the employees are submitting their income tax details. This follows the elastic pattern. Organizations need to ensure that during the final days of income tax submission, the application is highly available. This means 50-100 times more load than the normal application usage. This is the right scenario for a cloud based application.
Private or Public Cloud
Once it is decided to move the application to cloud, next important decision is to move it to private or public cloud. A private cloud gives you complete control over the hardware and it is built using ones own resources. All this control and security comes at the expense of overheads in management.
A public cloud is something that does not give you granular control over the infrastructure but relieves you of all the overhead in terms of management and operational costs involved in terms of server admins, patches, and operating system costs.
Choosing a Vendor
There are different types of cloud options availableInfrastructure-as-a-Service (IaaS), Platform-as-a-Service (PaaS), and Software-as-a-Service (SaaS).
The driving factors would be the technology stack, current developer skills in a company, cost of the services provided by the cloud vendor. Out of these, for enterprise application scenarios, IaaS or PaaS makes sense. On the basis of the technology involved and the team skills, the decision has to be made towards finalizing the PaaS or IaaS based vendor.
If the enterprise applications are comprised of one stack, its better to go with a PaaS based cloud like Microsoft Azure. The IaaS vendors provide virtual machines on the cloud and the enterprise has to build up the technology stack on it by itself. These are called virtual machine images in Amazon EC2.
Also as part of the evaluation, one can factor in the considerations as to what it wants to use the cloud for, be it storage, database, or compute. Also compute the opex cost of the vendors
Cloud is touted as an option that is highly available. However just moving the application to cloud does not imply that it will not fail. The application has to be designed and deployed in such a way that there is a failover plan.
Cloud computing is the new buzz and we would harness the benefits of cloud more when we make judicious decisions on what to move to the cloud and what
applications to have in-house.