Cloud is all about efficiency – you want to minimize the infrastructure and management costs while improving on the services needed. But rare is the occasion where you can start from zero – we all have some existing services in our businesses that we use every day and don’t want to be left without while moving to the cloud.
These days, we can choose among several strategies in how we can organize our information services while utilizing the benefits of cloud architecture. In this post, I’ll try to explain what’s offered and what are the pros and cons of all 4 types of cloud computing from the deployment standpoint.
Types of Cloud Computing: Private cloud
If you want to start exploring a cloud solution without the need to search for the provider and start moving your services to the public cloud. If you have some underutilized hardware resources (ie. Servers) you can start building your own private cloud solution, whether you go with a commercial solution (for example, VMware) or opt for an open-source solution like one of many OpenStack implementations.
What are the advantages of a private cloud? Well, you can start small, maybe just some ephemeral services and then go further and start moving more important services to it. Everything is contained in-house, both apps and data, and you’re in total control – sometimes it is required that you keep sensitive data away, under a key.
However, there are disadvantages as well: you need to provide for the hardware resources; you need to provide for installation, configuration and management of cloud infrastructure itself, aside from apps and data. Usually, you don’t have enough hardware resources to provide for geo-diversification and redundancy of locations, and thus prevent major outage of your services if there’s a problem with your primary location. You are in total control – ergo, you are the only one responsible for everything that happens to your apps and data.
Types of Cloud Computing: Public cloud
Public cloud is the one strategy that we usually think of when we talk about cloud solutions. This means that you’re going to use a public cloud infrastructure commercially offered by some public cloud provider, like Amazon Web Services, Microsoft Azure or Google Cloud Platform. Public cloud here also means that you’re going to use a single provider for all your cloud needs.
The pros of using the public cloud are numerous:
- You don’t need to provide for hardware resources, as you’ll be using the ones provided by your cloud provider
- You’ll have a large choice of services offered by your provider, so you don’t need to install and configure these
- You pay only what you use and how much you use it.
- The responsibility for securing your services and data is shared between the provider and you – you’re responsible only for your app and data, and the provider is responsible for everything else. And you can use services for protecting your sensitive data offered by your provider.
There are some cons:
- Your data is located somewhere else, and often you don’t even know where exactly it is.
- Cloud infrastructure services differ from one provider to another. This means you have a vendor lock-in.
Types of Cloud Computing: Hybrid cloud
Hybrid cloud is a marriage between your private cloud infrastructure and your single public cloud. This is the preferred way for companies to migrate some of their services to the public cloud when they already have their private cloud infrastructure. There are solutions to seamlessly and securely connect private clouds with public cloud setups.
There are two main reasons why you would need a hybrid cloud strategy. One is that you already have the private cloud infrastructure that you want to migrate to public cloud in part or in whole. The best way to do this migration, while minimizing the downtime of your services is to connect your private cloud infrastructure to the public cloud setup and then migrate services one by one. Many public cloud providers offer services to ease the migration and movement of services, as well as the integration of services that remain on the private side to those on the public cloud.
The other main reason is the need to keep some (usually the most sensitive) data in-house exclusively, while still utilizing all the good things that public cloud provider offers. That way you get the best of both worlds.
The main problem with hybrid clouds is the need for management, monitoring and configuration services that can integrate private and public cloud. Some public cloud providers offer some management services that can span both your private and their own cloud infrastructure.
Types of Cloud Computing: Multi-cloud
Multi-cloud strategy means that you’ll be using more than one cloud solution. Although at first glance, this definition covers hybrid clouds, multi-cloud usually means that you’ll be using public cloud infrastructure from more than one public cloud provider, with or without the private cloud as well. The emphasis, of course, is on the use of multiple public cloud providers.
Why would you even want that? Well, there can be several reasons for that:
You already use services from one public cloud provider but somebody else offers a service that your current provider does not offer, or their service level is not on the same level with the same service from the other provider. However, for some reasons, you don’t want to migrate services already on your current public cloud.
You don’t want to keep all your eggs in one basket – diversification of infrastructure offerings can be more efficient and cost-effective.
The biggest obstacle for spreading from single/public cloud to multi-cloud is again vendor lock-in. You need to connect different virtual data centres, each with their own management, configuration and monitoring services. This mostly means that you’ll need some apps that will integrate monitoring, configuration and management services for these diverse public clouds into one easy to maintain the system. You don’t want to stress out your ops team by forcing them to use native tools for maintaining public cloud infrastructure that your provider offers. You want to have one set of tools that can work with either provider and integrate them into one big setup. The other problem is to provide identity and authentication services that can span multiple clouds so that your users do not need to have a separate set of credentials for accessing services on different clouds.
A multi-cloud strategy is mostly used by big companies, but even smaller enterprises can utilize the benefits of multi-cloud.
Anyway, no matter what your requirements are, you can now choose between different strategies of employing cloud architecture that will fit your needs perfectly.