The What’s What of Cloud Delivery Models
Sure, cloud computing has now been around for several years. Here we look at the, sometimes confusing, different terminology used to describe the various types of cloud delivery.
One factor contributing to this is that innovative computing vendors are constantly developing their positioning and coming up with new marketing speak to differentiate their offer. The terms and titles they have introduced to describe services they offer can be very confusing and often misleading.
A public cloud is an infrastructure delivered over the internet by a cloud provider who makes computing resources, such as processing power, memory or storage, publicly available over the internet. These resources are hosted on the provider’s servers in one or many data centres located all over the world.
The infrastructure is multi tenancy which means it is shared among other customers.
Good examples of public clouds are free services such as web-based email from Google or Microsoft. In 2006 Amazon became the world's largest provider of public cloud computing. It assessed that a large part of its global computing infrastructure was unused and therefore made a strategic decision to set up a new entity called Amazon Web Services (AWS) dedicated to renting out its spare capacity over the Net.
This option offers the most flexibility as you are only charged for the resources that you use on a pay-as-you-go basis but doesn’t have the security offered by private cloud.
A private cloud is a cloud infrastructure is hosted on your own servers on your physical premises. You access the resources you use through secure network connections, much like an Intranet.
Amazon and other providers allow to make your own secure private cloud on their public cloud infrastructure. This is known as a Virtual Private Cloud (VPC), using virtual private network (VPN) connection
This offers is far more secure but also more expensive requiring considerable technical expertise to design and build. You have control over managing your infrastructure and the costs of the resource associated to doing this.
A community cloud is a multi-tenancy delivery model that is shared among several different companies who share the need to meet specific computing concerns such as regulatory compliance. The infrastructure is on the servers on-premise or at the data centre owned by third party. This is then managed by either by the companies or by a Managed Service Provider (MSP).
Community cloud offers the benefits of a public cloud environment such as pay-as-you-go flexibility but with the stringent security and compliance of a private cloud.
A hybrid cloud is a combination of a public cloud and a private cloud. Some parts of your cloud are hosted on your own on-premise servers on your network and some of your cloud is hosted on a public cloud.
This option allows you to host sensitive information on your database servers in your private cloud in a more secure environment such as financial documents and back-ups, and to store other data sets on the public cloud, such as collaborative operational documents.
In a 2017 survey commissioned by North Bridge, Holly Maloney McConnell, Principal at North Bridge said:
"Cloud environments will remain predominantly hybrid in the coming years, enhancing the importance of a clearly defined cloud governance and orchestration strategy to optimize for security, self-service and agility, while minimizing costs.”