Best of both

A hybrid cloud composes at least one private cloud and one or more public clouds.

Read time 4min 10sec

Cloud computing has seen a significant uptake in business over the last year, with the emphasis being on private clouds, which have initially displayed some advantages over public clouds - particularly for small and medium-sized businesses.

For example, private clouds allow SMEs to deploy easily managed and more secure clouds, built on new-generation data centre virtualisation and automation technologies.

A key benefit of a private cloud is its ability to pool and dynamically allocate IT resources across any number of business units, allowing services to be deployed quickly and even scaled to meet growing needs. The use of these resources can be tracked effectively and, if necessary, invoiced to individual business units within the company.

Pros and cons

In a private cloud, the resource pool is no longer seen as a collection of servers. Instead it's the capacity of the pool that's important, including the number of workloads and applications it is able to support.

Significantly, a private cloud allows the IT department to deliver infrastructure, platforms and software applications without the need to allocate different infrastructure 'silos' to different departments, as the resource is managed holistically.

On the other hand, a public cloud's advantages include lower upfront costs, as all the costly data centre resources are held by a third-party service provider and delivered to the user 'as a service' in much the same way as water or electricity is provided by utility companies.

What's more, cloud service providers generally compete with each other on price, so it is possible to negotiate lower costs for computing services.

There are some drawbacks associated with public cloud infrastructures, with security concerns topping the list. Data loss is another. If the cloud host's infrastructure fails, will all the virtual servers 'disappear' and will all the data on this 'virtual hardware' be lost?

Amazon's much publicised cloud services crash earlier this year, which took down the sites of a number of high profile companies for hours - in some cases days - and, according to reports, permanently destroyed some data, underlines the vulnerability of public cloud services.

In the mix

Is the ultimate cloud computing solution a mix of public and private clouds? It's a notion that's crystallising rapidly as the concept of the hybrid cloud gains traction in the marketplace.

Is the ultimate cloud computing solution a mix of public and private clouds?

Martin May is regional director of Enterasys Networks.

Strictly speaking, a hybrid cloud is a composition of at least one private cloud and one or more public clouds. The private cloud element can be an on-premises cloud or a virtual private cloud, located remotely.

Typically, a hybrid cloud infrastructure is the result of a partnership between the user and public cloud provider(s) in terms of which certain resources are provided - and managed - in-house and which others are provided and managed externally.

In popular implementations, organisations use the public cloud for data storage and archiving, but continue to maintain in-house applications and infrastructures for operational activities on the private cloud.

Importantly, the hybrid cloud approach allows an organisation to take advantage of the scalability and cost-effectiveness offered by a public cloud, without exposing mission-critical applications and data to third-party vulnerabilities.

Because the hybrid cloud should deliver the advantages of public and private clouds in a seamless manner, it promotes the structuring of an agile business in which decisions are made more rapidly and where reactions to marketplace trends and developments are faster.

The challenge facing organisations contemplating hybrid cloud computing is to provide this seamless operation across all platforms, including cloud application programming interfaces and hypervisors or virtual machine managers.

According to Brian Byrne, a US-based cloud computing strategist, users often prefer to use their data centre tools to manage hybrid cloud environments. Ideally, they want to be able to create applications, or move existing applications between the public and private clouds without having to change anything serious like networking, security policies, operational processes or management/monitoring tools, he says.

Is this possible, bearing in mind the complexity with which hybrid clouds are generally associated?

The fact is that the legacy IT infrastructures within many organisations have evolved over time, and therefore lack form. Often, the most complex are the middleware environments.

Therefore, before embarking on any cloud computing endeavour, organisations need to audit their infrastructures and gain a clear view of the interdependencies of different IT services within them.

What's required is a fully rationalised and carefully defined map of all the interdependencies before they are deployed in a hybrid cloud. In this way, users can gain the upper hand in terms of management and enjoy a smooth and trouble-free implementation.

Martin May

Regional director (Africa) of Extreme Networks.

Martin May is the regional director (Africa) of Extreme Networks. The author of the book: “Everything you need to know about networking”, he is a leading authority on infrastructure security using NAC, IDS/IPS and other network-based technologies. With experience gained in Russia, Germany, UK, the US and various parts of Africa, he is directly involved with system design and implementation at enterprise level. His emphasis is on the evolution in network architectures brought about by the concept of cloud computing. May hosts regular workshops assisting South African dealers and resellers to understand the implications, complications, opportunities and international trends surrounding the cloud. A proponent of social networking for business, he is active on Facebook and makes extensive use of YouTube.

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