Cloud services are now an accepted, well used feature of nearly every business. It was estimated that in 2018 over 96% of all organisations use it in one way or another. The following article provides an overview of the differences between each of the three main cloud providers, AWS (Amazon Web Services), Microsoft’s Azure and Google Cloud. For more information, and what to consider when deciding whether or not to move to the cloud, see our article “Cloud or on Premise?“.
A public cloud is one made available to many customers by a cloud provider. It runs on remote servers managed by the provider, access being over the internet. It shares computing services amongst those customers even though their data is kept separate from each other. A private cloud, on the other hand, is not a service shared with other customers. The responsibility for management and maintenance of the data falls to the company, the owner of the data. Using the public cloud means that your data is stored in a provider’s data centre, they being responsible for the centre’s management and maintenance. A hybrid cloud environment is one that extends a secure private cloud to a public cloud when a demand for additional resources arises, without the risk of an internal overload, a mix of the two.
The advantages of the public cloud include resources not having to be used to manage servers; stronger security is available to small and medium sized enterprises (i.e. those with smaller budgets); and there is an opportunity to reduce IT costs by outsourcing to an efficient provider. Economies of scale also mean public clouds often cost less to run than private clouds for individual users. The downside can sometimes be with compliance and security: some organisations need to adhere to strict rules , one example being healthcare organisations in the US with HIPAA 1996.
The most important advantage for many is that a public cloud strategy allows an organisation to grow at an almost infinite rate, possible with an on-premises data centre but this can be expensive, without the need to buy more hardware nor with the responsibility to maintain a growing network.
The market leaders
The three leading public cloud providers are AWS (Amazon Web Services), Microsoft Azure and Google Cloud.
Choosing between the three (or others, such as IBM, Oracle etc.) is not only about pricing, one needs also to consider, for example, the size of organisation and its projected growth rate in addition to the budget available. There are also technical differences, which means that before making a decision you would be well advised to refer to an expert – a significant amount of investigating is time well spent when about to invest in a cloud partner.
Market shares and growth rates
In November 2019 Goldman Sachs produced a report stating that AWS, Azure, Google and Alibaba made up 56% of the total cloud market, projected to grow to 84% in 2019. It shows AWS in the lead with a 47% market share projected for this year, helped by reach and length of time on the market, with Azure at 22% and Google at 8%.
AWS’s biggest strength is that it dominates the public cloud market – being the most mature enterprise-ready provider, with the deepest capabilities for governing large numbers of users/resources. Azure and Google are behind Amazon, but they are rapidly narrowing the gap.
It should not be difficult for an organisation to access the services of any of the main providers, although each has a different structure and terminology.
AWS is hosted in multiple locations around the World. They are known as “Regions” and “Availability Zones”. Each Region is a defined geographic area, and is completely independent and designed to be isolated from other Regions. This achieves the greatest fault tolerance and stability. Each Region then has multiple, isolated locations known as Availability Zones (AZ). Each AZ can have multiple data centres (typically 3, and can consist of hundreds of thousands of servers), each one having their own power infrastructure, each AZ physically separated with a meaningful distance between them, up to 100km.
AWS not surprisingly has a larger global footprint than any other cloud provider, however its competitors are catching up.
Azure currently has 54 Regions worldwide and is available in 140 countries around the world. A “Region” is defined as “a set of datacentres deployed within a latency-defined perimeter and connected through a dedicated regional low-latency network”.
An Azure “Geography” is a discrete market, typically containing two or more Regions that preserve data residency and compliance boundaries. This allows a customer’s data and applications to be kept close by, if this is required. They are designed to be fault tolerant, to withstand complete region failure. “Availability Zones” are physically separate locations within an Azure region. Each Availability Zone is made up of one or more datacentres equipped with independent power, cooling, and networking.
Like Azure, Google Cloud is also expanding rapidly. Its resources are hosted in multiple locations known as Regions and Zones. The former is a specific geographical location containing one or more Zones (US-West1 has three zones, for example, US-West1a, US-West1b and US-West1c), each containing its own resources. Again, choice of location is available, and using multiple zones and regions will tolerate outages. Each Zone is isolated from other zones, and most single failure events will therefore affect only a single zone.