If you're in the Software as a Service (SaaS) business and not already operating in a fully virtualised, outsourced world, you've no doubt been considering it. Of the many choices available to you, Public Cloud is perhaps one of the least well understood.
What is Public Cloud computing?
The Public Cloud model is the flavour of computing virtualisation that makes virtual machines, on a shared platform, accessible to anyone via the internet. With Public Cloud services there is no need for you to invest in infrastructure; all the necessary hardware, architecture and operating software is owned, maintained and managed by your hosting provider. Individual virtual machines within that platform are made available to you in the form of a service.
How does Public Cloud compare?
If Public Cloud is just one flavour of cloud computing, what are the others and how do they compare?
- Private Cloud is a cloud platform created for the exclusive use of an individual organisation. Whether the Private Cloud is located on-site or with a provider, it will logically sit within the organisation's network and under the protection of its firewall and other security provisions.
- Hybrid Cloud systems are a combination of both Public and Private clouds. By using both, it is possible to apply the benefits of each to different areas of an organisation's IT requirements whilst mitigating their limitations.
What are the advantages of Public Cloud?
If Public Cloud services are a viable option for your requirements, you can expect to benefit from these advantages.
Scalability: Virtual machines within a Public Cloud system can be created, scaled and shut-down in an instant. A Public Cloud service can therefore easily scale to meet any changes in your needs - perfect for ISVs with rapidly changing demand.
Cost: Due to underlying infrastructure being shared and the ability to optimally size virtual machines in terms of computational power, memory and storage, a Public Cloud service can be implemented at a fraction of the cost it would take to implement a Private Cloud alternative. The inherent flexibility in cloud computing is also what enables pay-as-you-go utility pricing models with no capital outlay.
Management: As a subscriber to Public Cloud services, you will be free from the responsibility of maintaining and managing the infrastructure. Your provider will take care of hardware and software updates (optionally including your OS and applications) as well as implementing robust security measures. This leaves you to focus on other important areas of operation like development, testing and customer support.
And the disadvantages?
The perceived disadvantages of Public Cloud are often over exaggerated. With the use of a shared infrastructure, however, does come some limitations.
Security: While Public Clouds, from credible providers, are more secure than most SME IT infrastructures, there is a trade-off. First, you can only customise security factors at the operating system level - security at the physical level is under the purview of your supplier. Second, Public Cloud servers are, by default, visible internet-wide. This has been shown to lead to increased levels of remote scanning for vulnerabilities. Securing your server at the OS level is therefore essential.
(In)flexibility: Although virtual machines are very flexible in terms of scale and power, some choices may be made for you by the hosting provider. For example, with some providers, you may not have complete freedom to install just any OS or you may not be able to switch storage solutions i.e. from NAS to SDS. Check with you provider what is possible, and what is not, before signing up.
Compliance: Another important aspect emerges when considering the legal requirements around data management. It's possible for a public cloud service to be supplied from anywhere on the globe and its common for providers to operate from multiple regions internationally. Unless your provider can confirm the physical location of your data, compliance with certain Country, industry and company rules may be impossible. For SaaS vendors storing customer data and processing transactions, this could be crucial.
Choosing the right provider for your business
So you may have noticed that there is something of a Catch 22 about the Public Cloud model - the very factors that provide its strengths also contribute to its limitations. The key to harnessing the benefits of Public Cloud computing for your business and its customers is to work with a provider that has the expertise and experience to align the Public model with the unique needs of independent software vendors.