Out of the three main components of cloud computing - Software-as-a-Service (SaaS), Infrastructure-as-a-Service (IaaS) and Platform-as-a-Service (PaaS) - the latter is probably the least well-known, and certainly the least understood.
While SaaS is cloud-hosted software that can be accessed anywhere and IaaS refers to hosting of data on third-party infrastructure, PaaS doesn't have such a defined role in the cloud ecosystem.
Although its purpose and function are a little complicated, this doesn't mean it's an element of the cloud that can be ignored or overlooked. In fact, it's one of the cornerstones of modern application development, offering a platform on which to produce innovative and effective applications and services.
PaaS includes well-known platforms such as Heroku or Microsoft Azure, allowing developers to produce, test and deploy applications as rapidly as possible, ensuring they work as they should and can be rolled out already fit for purpose. Keeping them separate from an organisation's core operation means nothing else will be affected should something go wrong during the development process.
Another benefit of using PaaS is that it can be used as needed, rather than having to be left running all day, every day. This means they can be switched on during development and then turned off again when the app is ready to be deployed and migrated to a business's own environment, saving significant costs compared to an always-on dev environment.
If preferred, however, the application can continue to be hosted on the cloud platform where it was developed for as long as it's in use. This can have several advantages, including accessibility, particularly if you want to allow a certain person or group access to the app but not to corporate infrastructure.
There's also less maintenance involved, as the PaaS provider will manage the hosting and backend, choosing the best infrastructure for the individual application, while developers and those less experienced can focus on creating great, well-functioning products without worrying what’s going on in the background.
Ease of use isn’t the only reason businesses are switching from on-premise infrastructure to the cloud. PaaS offers significant cost savings compared to traditional set-ups, without the associated running costs such as backup and restore services and cooling, because the PaaS provider will take care of that.
They’ll also ensure the platform is secure and will guarantee a reliable level of uptime via service level agreements (SLAs), which will give you complete peace of mind that your data is safe and protected and your applications will keep on running.
Other essentials, such as analytics and monitoring are also normally offered by the PaaS provider. This means you can get detailed feedback on how many customers are using your web applications and how they’re using them. Web dashboards provide details on key metrics such as load times and bandwidth usage, so that companies can always check on the current status of their applications and be instantly notified of any failures or downtime.
PaaS providers normally offer a much greater level of scalability than is possible by hosting applications on a company’s own server infrastructure. Many PaaS providers offer features such as auto-scaling, allocating increased resources and bandwidth to your applications to cope with traffic spikes as they occur. That means customers won’t be left with blank screens or long load times if demand for a web app grows quickly or unexpectedly. The risk with auto-scaling is that fees can ramp up very steeply if there’s a huge spike in demand for the application, so it’s prudent to check that upper limits and notifications are in place beforehand.
PaaS offers businesses a great deal of flexibility. It can be used for rapid app deployment, in-house testing, or collaborative development between geographically dispersed teams. Virtual OS features can normally be changed or upgraded quickly. And when apps are ready to be shared with the public or customers, there’s normally no delay: they can be put live without any downtime.
On the downside, the choice of provider can be limited depending on what development languages or platforms they support. That increases the risk of vendor lock-in, making it difficult to jump ship to another provider if your current PaaS provider suddenly increases their prices. Developing applications in the most widely used languages mitigates this risk, to an extent.
Some companies may choose to go for a hybrid PaaS solution, with some data and services retained on the company’s own servers and some hosted in the cloud. This allows companies to continue eking the maximum value out of their current infrastructure, whilst enjoying the scalability benefits of the cloud. Indeed, some may choose to use PaaS as a capacity-on-demand fallback for applications running on their own in-house servers. This is only appropriate for selected types of application, however, and can increase complexity.
