Hybrid cloud computing

Hybrid cloud computing is the future: all predictions point this way. Private and public clouds have their advantages and drawbacks but hybrid combines the best elements of both. The question is which applications should enterprises move where? And how do they get the best from the disparate mix of technologies?

Starting with the easy answers, most enterprises are clear that the big hitter applications - such as databases, virtual desktops and mission-critical processes - should remain in-house. The first two are resource-hungry and don't transfer well to a remote model, while CIOs and CEOs tend to feel more comfortable with retaining full control over data and processes that are core to the company. Additionally, depending on your industry, there will be processes and applications that you need to keep in-house for regulatory reasons.

Some applications transfer better to the cloud, such as -- broadly speaking -- storage and computing. In this case, you might keep your analytics database in-house while moving the processing of it into the cloud, paying just for what you need, when you need it. In the same vein, you can use cloud resources for bursting, such as the monthly invoice of cheque or payroll run, or for providing additional servers for test and development purposes. One company uses a private cloud for a that needs a compute-intensive, low-latency rendering farm and has optimised its private cloud around that, while the public cloud handles the front end for management and access.

And many companies are looking to use multiple cloud providers, seeing the integration issues involved as secondary to the benefits of utilising best-of-breed providers.

The problem at this point is to integrate all these services into something approaching harmonious whole. Ideally, applications in the cloud should look exactly like those in your own datacentre. This will involve a fair degree of integration work, but there are few standards out there in cloud-world so that integration work will need to be done in-house.

Of those standards that do exist, it's worth looking at cloud platforms that use technologies such as OpenStack and CloudStack, which offer some common user interfaces and APIs.

Cloud management software, some of which uses OpenStack or CloudStack technology, promises to provide resource management across all types of cloud. So for example, you should be able to manage servers and networks, provision new servers, manage applications, and automate repetitive tasks.

There is an alternative to the DIY hybrid cloud. Cloud management platforms are starting to emerge, offering a form of abstraction from  underlying cloud providers. You could think of it as a form of cloud virtualisation. Typically, they work by providing agents that run on your cloud servers and allows you to manage them all using a single user interface. Their main drawback, apart perhaps from not providing all the features you might want, is that the set of cloud providers they support is limited.

In summary, then, ensuring that the right applications are in the right place is key for performance and security. And although layers of cloud abstraction are starting appear, it's still early days and the technology has a way to go before it can be called mature.