Migrating to the Cloud: Which Model Is Right for You?
Cloud computing is a relatively recent trend, and several organizations have opted to migrate their databases and services to the cloud. There are different cloud computing models available—which is right for which situation? Let’s look at the three options.
Public Cloud
Public cloud is the most common cloud computing model and is composed of shared infrastructure and resources hosted in a public domain. Typically, public cloud service providers host the infrastructure at multiple data centers and make their services available over the internet.
Consequently, public cloud does not take network security into consideration. Choose the public cloud if your applications and services are to be accessible to anyone with access to the internet.
Private Cloud
A private cloud hosts the infrastructure and services on a private network that is accessible only to those who have been explicitly granted access. The architecture of a private cloud is no different than that of a public cloud, except that it is hosted over a secure network, such as a data center for a single organization. This increased security may involve additional configuration.
Most cloud service providers provide an option of a virtual private cloud (VPC), or an isolated section of the virtual network in which a user has complete administrative control over the networking environment, including the choice of public IP addresses, routing tables, and subnets. A user may customize the network to provision some of the resources in public subnets and others in private subnets. Access to services may be regulated with network access control lists.
Hybrid Cloud
A hybrid cloud is a mixture of public cloud and private cloud models, where an organization-based data center is combined with public cloud hosted services. The hardware and network at the local data comprise the private cloud, and the hardware hosted on a cloud network comprises the public cloud.
Some public cloud service providers provide services and hosts dedicated to a single user account, isolated from servers and services for other users at the hardware level. In effect, a dedicated service or server is equivalent to a service or server hosted at a private data center, except that it is hosted by a public cloud service provider.
You could want to use a hybrid cloud if you have data that needs to be stored in a secure environment, such as user credentials that should be stored in a private cloud but services and applications that need to be available publicly.
An organization also may extend its resources and infrastructure capacity by using a public cloud. Extending to the public cloud infrastructure could be integrated into the design model of an organization as a permanent feature, or it could be for temporary scaling of resources when the load on a private cloud exceeds capacity.
If you want to migrate to the cloud, use a private cloud if isolation of the network is a priority. Use a public cloud for publicly hosted services. And use a hybrid cloud if some of the services and data need to be secure and isolated, while other services and data need to be accessible to the public.
