In the past, a lot of confusion revolved around what was needed to migrate to the cloud. Now we have clearly defined options: The Public Cloud, Private Cloud and Hybrid Cloud. This provides clarity at a high level and these options are the first choice to be made in any cloud migration strategy.
With business systems moving to the cloud now as common practice. It is important to fully understand the difference between the three choices, to decide what’s best for your organization in the long-term for cost reduction and improved business efficiency.
The public cloud is provided by a large vendor and hosts multiple tenants simultaneously across its network. The largest and most popular public cloud hosts are Microsoft Azure, Google Cloud and Amazon Web Services (AWS). Additionally, there are other platforms such as Oracle Cloud and IBM BlueMix.
The service can be free, freemium, or subscription-based. Subscription-based pricing is generally based on the computing resources used, so you only pay for what you need. Another huge benefit of using the public cloud as opposed to private is the cloud vendor is entirely responsible for the development, management and maintenance of its computing resources.
In this environment, for example, custom software applications are developed in Microsoft Azure technology. And hosting is provided by Microsoft themselves charged on a usage basis. Or Azure-enabled software such as Microsoft Office 365 is purchased for the business on a per-user per-month basis to replace internal systems.
The public cloud offers high elasticity and scalability at a low-cost subscription-based pricing tier. With no requirement to invest in infrastructure, and the IT staff to maintain it, it is the most common type of cloud hosting.
The public cloud is ideal for software development and test environments. As well as for additional resources during times of peak demand.
We developed a system for Appcan, a company providing cost-effective ways of gathering and managing fieldwork data. The system was designed as a serverless Azure application. It is designed to auto-scale out to multiple physical servers as load increases, with SQL Azure that can be scaled up and down as load dictates.
The term ‘Private Cloud’ has been coined to cover business systems which have been opened out securely to the wider world. This is useful for agile working and mobile devices as well. As for internal use to enable ‘always-on’ and on-premise and remote work collaboration.
Traditionally, business systems were locked down within internal networks, and with multiple sites that were connected via secure private wide area networks (WAN). But you needed to connect via VPN, or other, often clumsy, methods. This ensured the process remained difficult for the user and slowed down work activities.
Today, with the more common practice of having mobile workers or distant clients and partners, business systems are opening up, using private cloud platforms. This can include Microsoft SharePoint, custom business systems or custom portals to provide secure online connectivity and integration to back-office systems.
Secure private cloud systems can be deployed either on-premise or at an external data centre. Deploying a private cloud application means you do not necessarily have to move systems to external hosting providers. You can keep them under your own direct control.
The private cloud is ideal for organizations who need to maintain high levels of security and control but still need to meet the demand for remote and agile workers.
As an illustration, we provided consulting services on the design for a globally available deployment of SharePoint for NATO Science and Technology. To enable scientists around the world to collaborate and communicate securely in real-time. This utilized very secure on-premise deployed Windows, SharePoint and SQL Servers.
The third option is a mix of the public and private cloud – the hybrid cloud. In this scenario, online software is securely integrated with offline back-office systems. An example of this is where extensions are developed to back-office business systems to enable both call-centre staff and end-public users to access the system for customer-service and self-service functionality.
On the hybrid cloud, applications and data workloads share the resources between public and private deployment. The environment itself should be impeccably integrated, ensuring optimal performance and scalability for changing business needs.
How it is configured varies from organization to organization, depending on requirements and policies on security, cost, scalability, efficiency and more. A common use of the hybrid cloud is using the private cloud environment for general workloads and during occasional spikes in network traffic, moving to use the public cloud resources.
The hybrid cloud is ideal for organizations with different IT security and compliance requirements. And for those with existing SaaS offerings that must be delivered via a secure private network
Ballard Chalmers worked alongside the IT staff of Imagination, a creative communications agency to move their Global Finance System from SQL Server on-premises to a hybrid solution. The live servers were hosted by Microsoft Azure and replicas of the databases were kept up to date on-premises in London for DR.
By Andrew Chalmers, Managing Director at Ballard Chalmers
Originally Published 2014, updated 2019
About the author
Andrew Chalmers is a co-founder and the Managing Director of Ballard Chalmers. With over 40 years’ experience in business management, Andrew brings the business-side experience to Ballard Chalmers to complement our Chief Technical Officer’s technical leadership.
In 1998 Andrew created and established one of the very first cloud software development consultancies in the UK, which developed a very early-adoption corporate intranet for Hewlett Packard Europe amongst many other ground-breaking projects.