Clouds must have five essential characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity or expansion, and measured service. On these fundamentals, cloud designers have created a whole new IT approach.
There are three ways to deploy a cloud: public, private and hybrid. Public clouds, such as Amazon Web Services (AWS), are controlled by their owners, from whom you rent computing services. In contrast, a private cloud runs on your own servers using cloud software such as OpenStack. A hybrid bridges the gap between public and private using your own special mix of public and private cloud services.
No matter which model used, there are three main ways to consume cloud resources:
1. INFRASTRUCTURE-AS-A-SERVICE (IAAS)
The building block for all the other cloud services, users are given access to physical or, more commonly, virtual servers. These provide file storage and other fundamental computer services, such as firewalls, load balancers, virtual LANS, and domain name servers.
Advantage: scalability – you can quickly ramp up additional resources. For example, if storage needs balloon from the terabytes of a private IaaS to a public cloud’s petabytes, you can master the expansion simply by paying for more room using a hybrid model.
2. PLATFORM-AS-A-SERVICE (PAAS)
Take an IaaS and add a software development stack to it. Now you have a PaaS. You can take existing in-house applications and migrate them to a cloud. This makes your programs more elastic.
Advantage: with a PaaS, if your user base goes from hundreds to thousands, your resources can expand to meet client needs without overprovisioning.
3. SOFTWARE-AS-A-SERVICE (SAAS)
SaaS started as a variation of client-server computing and then took a left turn into application service providers in the late 1990s and early 2000s. SaaS became mainstream because of two factors. First, the cloud architecture’s elasticity made it possible to deliver applications without manual intervention. And second, the web browser became the universal user interface.
Advantage: fast deployments – SaaS software solutions can be implemented in a matter of weeks versus months.
CLOUD – PROS AND CONS
Besides the financial benefits of a cloud model, there are three other major reasons to use Everything-as-a-Service (XaaS) with your existing servers and a public cloud in a hybrid model:
- Faster time to market: instead of hours in manual setup time, it takes less than a minute to set up a new server automatically.
- Improved ongoing support: for most as-a-service models, ongoing support and maintenance services such as service desk and network monitoring can be handled by the cloud provider.
- Resilience: with a hybrid model, IT infrastructure is stored on your site and also on a public cloud. This way, even if disaster strikes, you still have access to data and programs.
Now, here are some things that can go wrong with a cloud-based IT infrastructure:
- Security concerns: the more you turn your resources over to the public cloud, the less control you have over them. You are, after all, leasing servers instead of owning them.
- Compliance: run-of-the-mill public cloud can’t be trusted with the sort of data used by Financial Services and Healthcare organisations. You’ll need to keep it within the confines of your private cloud.
- Performance: cloud-based application is only as good as your users’ internet connectivity. If your application is graphics heavy or requires video, you’re going to have trouble keeping your customers happy.
This balancing act of cost, flexibility, control, risk and security is pushing many organisations to adopt hybrid IT strategies. But you don’t need a cloud for everything. That’s where hybrid IT comes in. Infrastructure has to be everywhere, at the right cost, at the right performance, with the right management, at the right scale. And it all has to work together seamlessly. A hybrid infrastructure is one that seamlessly combines public cloud, private cloud and traditional IT.
We partner with Hewlett Packard Enterprise, a world leader in technology, inspiring innovators and entrepreneurs across the globe with their server, storage and software solutions.
‘Clouds and Hybrid IT – A Primer’ taken from article entitled ‘How Hybrid IT Enables the Software-Defined Data Centre’ which appears in HPE guide entitled ‘Foundations of Hybrid IT’