Over the years, enterprise application trajectory observes the paradigm shift towards web based applications. The emergence of cloud computing models is providing alternative guidelines for enterprises in terms of functional & non-functional requirements, management and costing for IT enabled services. These models offer ubiquitous, scalable and on-demand network access to IT resources (e.g., networks, servers, storage, applications and services) that can be provisioned with minimal management effort or service provider intervention. Cloud service providers offer both private and public cloud models but, first an enterprise thinking to deploy a cloud service must carefully examine its own need in terms of mission critical service components, security and cost along with the advantages and disadvantages of both private and public clouds.
Public cloud infrastructure is provisioned for open use through internet by general public. Enterprises that use web servers where security and compliance requirements are not very stringent normally prefer to use public clouds. For example, public cloud services are available in the form of web based email, data storage or file transfers over the internet, web hosting and so on. This model is most suited for start-ups and small enterprises because of minimal set up costs. The IT resources are shared between multiple users publicly and the infrastructure, services, usage and security policies are managed by the service provider. Enterprises that have security, compliance and data privacy as their top priority are using private clouds.
Private clouds are deployed inside mission specific firewall setups and offer robust IT security for the enterprise. But, for having in-house private clouds the enterprise needs to invest heavily to setup the infrastructure and in running and maintaining the infrastructure. Private cloud implementations are found in areas such as banking and financial institutions, large enterprise organizations, government organizations, etc. where only authorized users are able to access the system.
It is essential to understand the intricacies of both these models before deciding to choose the appropriate model for the enterprise. But in coming days the overall cost implications, state-of-art technology, elasticity of demand, perimeter complacency, maturity of security tools and techniques, security compliant SLA, widely experienced cloud professionals will give public cloud an edge over private cloud.