Public, Private and Hybrid Cloud

We are now in a world of 3 types of cloud for managing datacenter applications. Private, Public and Hybrid. Each have their own benefits and challenges. I’d like to talk about how I see the three types and where the value is.

Public Cloud

uberAmazon Web Services have done a great job at providing the worlds most popular public cloud offering. Anyone with a basic knowledge of VMs can fire up an environment and get going in literally minutes. There are others in the market who do this very well too. RackSpace, Google, VMware, etc. Each of these has the simplicity and scalability to allow you to move almost any application out of your datacenter and into the big fluffy outside world. This is the cloud equivalent of getting a taxi. You don’t need to know how to drive, you pay for what you use, you don’t have to maintain the car, someone else manages this entire service for you.

This makes perfect sense for a spontaneous journey from one place to another (From the cinema to your favourite pub for example). These are short journeys and usually havent been planned. You need transportation from A to B quickly and at a reasonable cost. I like to refer to these kind of use cases as the “exciting” ones.

When it doesn’t make sense to take this approach is for example when you have a recurring business trip and you have to drive every Monday for 2 months from London to Cardiff (3 Hour drive each time). Then it is far cheaper and makes more sense to buy a car and drive yourself (the “boring” use cases).

Private Cloud

teslaA private cloud is essentially an automated datacenter. There are cloud management tools of varying maturity (OpenStack, VMware vRealize, HP CSA etc.) which allow you to achieve the same look and feel of the public cloud, so for this comparison we will assume the experience is the same. A user logs into the portal and requests services which are deployed within minutes, there is a life-cycle associated with this, an internal cost and reporting functionality. The difference is you need to buy/rent a datacenter and manage all the associated challenges that go along with this.

This is the cloud equivalent of buying the car. You chose a car which has the features you need, you pay potentially a sum of money up front for it, you get it serviced, you insure it with a courtesy car if things go wrong (Disaster Recovery). Buying this car and driving it everywhere is the equivalent of having only a Public Cloud. This is the best option for your “boring” strategic use cases because of the inherent security, control and long-term cost implications.

Hybrid Cloudhybridcloud

No, this isn’t where I’m going to suggest you buy a Prius….

Knowing that you can get benefits from both approaches on their own, it makes a lot of sense to leverage both and have a hybrid cloud. You use the taxi for short spontaneous trips and drive the car when you have a more strategic journey.

Private cloud allows you to be stable, cost-effective and maintain control over your data and the security around it. The problem is that it doesn’t always allow as much flexibility as public cloud. For example if you don’t have the capacity in your datacenter for your new exciting project, or you want to completely segregate this new project from existing infrastructure whilst its being developed. Developers typically love the flexibility of public cloud and the increase in shadow IT is testament to it.

Connecting the two gives you all of these benefits, but if it isn’t a seemless integration, then you again lose the control and risk things becoming unmanageable. For a hybrid cloud, you need to have a unified portal, allowing users to choose from a single catalog where their applications will be deployed. There should be a network which is highly secure and flexible enough to allow you to move your workloads from one to the other. You should have a visibility into all of your applications and their locations at a granular level to make workload placement decisions more effectively. Finally, whats important for the CFO is understanding the costs of both. A proper show back and charge back integration is essential, otherwise you cannot prove the value that cloud is giving you.

So my personal tick-list for the minimum features for a hybrid cloud deployment are as follows:

  • Unified Portal – This could even be your in-house portal but must extend to leverage both Public and Private integration through APIs.
  • Secure extended network between the two – Think SDN
  • Unified capacity management – See both public and private usage alongside each other
  • Unified approval system – Make sure the right people know what is being deployed and have the chance to change it
  • Unified cost qualification and reporting – Understand how best to utilise your cloud environments

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