One of the reasons that Cloud computing can be a challenge to understand is that it can be different things to different people. Recently, the public's perception of what the Cloud is, has been defined by Cloud file storage products including Google Drive and Drop Box.
The technology to provide these services, and indeed many other current Cloud products, existed long before they were referred to as Cloud products. That's not to diminish their relevance. In our opinion, it's the all-pervasive nature of how our digital lives are moving from siloed individual machines to unifying public internet enabled and available platforms that articulates the true relevance of 'The Cloud'.
Below I detail some of the practical ways businesses are starting their Cloud journeys. In many instances their Cloud systems are as private as when they existed in their own datacenters. Apart from reduced running costs, the big difference now is that select aspects of those Cloud systems can be made available to individuals or other remote business services at the flick of a switch.
The term Cloud, in relation to computing, was actually popularised in 2006 when Amazon launched its Elastic Compute Cloud product. This product was a set of Amazon hosted services that allowed administrators to deploy software to its servers using a simple tool set. With this product amazon introduced one of Cloud computing’s key principles, scalability. At the touch of a button the administrators can commission the virtually unlimited resources at Amazon's disposal and deal with any level of user demand. The latest version of this product Amazon EC2 forms part of the full Amazon AWS Cloud platform and along with Google Cloud Platform and The Microsoft Cloud (Azure) are leading the way in creating full Cloud ecosystems.
Amazon's first Cloud product, similar to offerings by Google and Microsoft, is referred to as a Platform as a Service (PaaS). Amazon provide a Cloud platform and an administrator or developer can simply press a button to deploy an application or website to it. Microsoft have a PaaS offering within their full Cloud eco system. With Microsoft 'Cloud Services' PaaS, different parts of an application can be deployed to separate Cloud resources. This is very powerful and scalable as it means, as a business, you only need to request resources for parts of the application that are coming under high load for as long as they are under high load. PaaS is the most closly related of the three definitions to Serverless.
We believe the 'Platform as a Service' model offers the greatest return on investment when moving to the Cloud. However, lots of existing applications have not been written with Cloud platform hosting in mind and initially there wasn't a great appetite to start pulling apart legacy code to make it PaaS compliant. This is where Infrastructure as a Service (IaaS) comes in. With IaaS you can provision your own prebuilt full operating system resources in the Cloud and deploy your full legacy application to it using remote access tools. If you need to install some special patches to make your software work then you have full exclusive access just as if you were working on your desktop.
Software as a Service (SaaS) is probably a bit more difficult to define as the technology of the apps involved has changed recently. A common theme for defining the consumption of Software as a Service is that it's paid for on an ongoing subscription rather than as an outright capital purchase. These SaaS products are hosted by the supplier and made available to the client. Systems like these are generally web based but use the latest web technology to offer the user a much more fluid, almost desktop experience. It's a great way for companies to consume software as there are no internal support headaches and everything is managed on your behalf.
Microsoft Office 365 is also classed as a SaaS product but it muddies the water slightly. Office 365 does have a limited web browser version but most users download a full copy of the standard office product as part of their subscription. Regardless of how it's installed, the reason the whole Office suite is now an important addition to the Microsoft Cloud ecosystem is that it can fully integrate with the Microsoft Cloud Single sign on permission system. This means users across an enterprise only need one login to access all their applications. It's also been redesigned so apps built to enhance even the desktop installed version of office can run in the Cloud but still access elements of spreadsheets, documents and emails etc.
What's the difference between PaaS and Serverless?PaaS and Serverless are very similar in that we deploy or use functionality without worrying about how it's hosted. These platforms can scale themselves, accommodating any level of demand. Serverless can be further characterised by offering less in the way of control and it has tended to host smaller bite size elements of functionality. As a business, you can worry less about Serverless sitting Idle whilst still being billed than you should with PaaS as Serverless tends to only bill when running. However, it is still possible to select a performance tier that is higher than necessary for both PaaS and Serverless so even though you save because you are not paying for idleness you can still pay much more than necessary. Therefore these facilities should still be regularly monitored and reviewed.
Three different types of Cloud adoption strategy have emerged including Public Cloud, Private Cloud and Hybrid Cloud.
These strategies are adopted for various reasons, sometimes including mistrust, governance considerations and also practical considerations i.e. a huge investment in corporate datacentre infrastructure!
The public Cloud is predominantly what we have been discussing and involves administrators installing or provisioning software directly on the platforms and systems of the Cloud host company. Public Cloud is directly accessible over the internet. Applications can be secured with advanced encryption technology and access can also be restricted so users of certain identified machines or from certain companies only have access.
The Private Cloud is a model that uses resources which are dedicated to an organisation. Private Clouds have tended to be used by larger corporate enterprises and involve more Infrastructure as a service rather than offering platform services but that's changing. Azure Pack makes available all the tools from the public Cloud to a private corporate Cloud datacentre.
Private Clouds have received some criticism as they do not offer the main benefits of Cloud computing i.e. systems will not automatically scale and they still need lots of looking after! Also, for many types of private Cloud the actual physical hardware has to be provisioned up front even when it's underutilised.
The Hybrid Cloud is an exciting development. It has been around for a while and is now maturing into something truly powerful. With a Hybrid Cloud you can benefit from all that's available in the public Cloud but have it privately linked directly to your own existing infrastructure. You can authenticate existing company users and share resources between your existing infrastructure and the public cloud.