Migration of Applications to Cloud

To migrate an application to cloud there are 4 possible options:

1. Rehost: Redeploy the application on HaaS (Hardware as a Service) such as Rackspace or IaaS (Infrstructure as a Service) such as EC2 virtual machines.

2. Refactor: Tweak existing application (usually web application) to run on IaaS platform (such as Amazon EC2.

3. Rebuild: Rewrite your application (usually web application) and then port it to cloud (utilize SaaS – Software as a Service such as Force.com, PaaS – Platform as a Service such as Windows Azure). You may also utilize Haas and/or IaaS.

4. Replace: It is clear slate approach. Maximum flexibility is available. One can choose to use SaaS (such as salesforce.com), Paas (Microsoft Azure, Google AppEngine, Force.com), and/or IaaS (such as Amazon EC2).

So which one are you doing?