A public cloud is a model wherein a third-party provider hosts any “as-a-service” technology, including hardware, software, monitoring and logging solutions, identity management, remote resources for at-home workers and other data centre solutions. When organisations do not have the real estate or resources to house internal infrastructure, they turn to third-party cloud providers for advanced technology. Organisations only pay for resources used, so it’s typically much more affordable than housing the infrastructure locally.

A Brief History of the Public Cloud

The idea of a centralised cloud system has been around for decades, but cloud computing took off in the last ten years as a cost-saving benefit for organisations that want to leverage the latest technology but don’t have the staff or infrastructure to build it in-house. As more organisations realised the cost-savings and efficiency of the cloud, the public cloud became ingrained in almost every network.

Cloud computing is championed by several prominent vendors such as Amazon, Google, and Microsoft, but other public cloud providers offer competitive services. Amazon’s web services generate $4.7 billion every year, so it’s a powerhouse for public cloud computing. Compared to two decades ago, the cloud is now an integral part of many organisations’ infrastructure.

How a Public Cloud Works

Organisations that leverage cloud technology can create virtual machines, serverless applications, and cloud-native resources. All resources run at the cloud provider’s data centre, which supports the hardware. The organisation manages configurations and cloud service actions, but the provider maintains and houses the hardware.

To a user, the location of the software is unimportant. Usually, the software runs in the user’s browser but input and output process on the cloud server. Data is also stored in the cloud, and permissions and authorisation are often integrated with cloud technology. Monitoring, logging, and other integrations can also be implemented in the cloud.

Why Choose a Public Cloud?

The cost to house the latest technology for most small-to-medium enterprise corporations with on-premises legacy infrastructure is unfeasible. Cloud computing offers an affordable way for small businesses to access the latest technology (e.g., artificial intelligence) without the expensive costs. Large organisations also use cloud computing to cut down on technology budget requirements.

Additional reasons organisations choose a public cloud:

  • Reduced costs on expensive infrastructure: Because you only pay for used resources, it’s much more cost-effective to use cloud computing.
  • No hardware maintenance: The cloud provider’s on-site personnel maintain resources, lowering overhead for your organisation’s administrators and IT staff.
  • Virtually unlimited cloud resources: A public cloud can offer petabytes of storage for disaster recovery, production, and archives, which would be expensive and take too much real estate to house on-premises.
  • Reliability and availability: The cloud rarely fails, and it supports any users located anywhere in the world, making it beneficial for organisations with a remote workforce.

Architecture of a Public Cloud

The type of public cloud that you use depends on its architecture. The three main architectures are based on functionality, but they also serve specific corporate needs. You can have only one or all three of the main architecture types. These types are:

  • Software as a Service (SaaS): SaaS is probably the most commonly used public cloud. Several services run in the cloud, such as Salesforce, where the software is in the cloud but available to users in a browser or mobile device.
  • Platform as a Service (PaaS): A PaaS extends a SaaS environment by hosting additional tools and development software to customise your user experiences. These platforms include services such as Google App Engine and Heroku.
  • Infrastructure as a Service (IaaS): When you need to extend hardware, a public cloud offers firewalls, IP addresses, network resources, and servers. Some organisations use IaaS entirely to build a network to power their business growth and productivity.

Benefits of a Public Cloud

Every move to new technology has its benefits and disadvantages. The benefits of migrating to a public cloud far outweigh the disadvantages. The benefits of leveraging a public cloud over installing infrastructure on-premises include:

  • Access to new advanced technology: The latest and greatest cutting-edge technology was traditionally unattainable for small businesses, but a public cloud offers access to anything hosted by the cloud provider.
  • Scalability: When an organisation needs more resources, it can provision any technology from a centralised dashboard. Administrators can scale vertically or horizontally with only a few clicks of a button.
  • Flexibility: Administrators can provision technology and then deprovision it when it’s no longer needed. This gives organisations the flexibility to scale up or down as needed.
  • Analytics: Every cloud provider furnishes reports so that administrators can determine where resources can be optimised to lower costs and makes suggestions for better provisioning in the future.

Challenges With a Public Cloud

A public cloud has several benefits, but it also comes with challenges. These challenges can often be overcome by carefully monitoring cloud resource usage and using outside consultants to help manage them. The main challenges are:

  • Unexpected costs: Cloud resources are often cheaper than building on-premises infrastructure, but misconfigurations or incorrect usage can actually cost more in the long run. Resources must be monitored and reports reviewed regularly to identify inefficiencies.
  • Untrained staff: Many security resources and advanced technology require the right staff to configure and implement. Smaller businesses might need to hire more administrators or find outside help to ensure a smooth rollout.
  • Limited control: Because businesses use resources configured in the cloud, they have no control over physical machines. This challenge requires trust in the provider to manage hardware and software without any malicious intent.

How Migration to a Public Cloud Works

After an organisation decides to use a public cloud, the next step is to audit resources, data, and access permissions and build a plan for migration. Successful and seamless migration usually involves a plan, migrating a test sample of data to see results, optimising the test-run after review, migration of production data and the final cutover.

Generally, the steps to migration include:

  • Evaluate business needs and where procedures can be improved in the cloud.
  • Select a cloud provider that has the resources to fit your corporate needs.
  • Calculate total costs for your cloud budget.
  • Determine how new procedures and ways migration will impact your business and users.

The above steps are general, and the details depend on your business needs. Once you decide to migrate to the cloud, you must go through specific steps to validate that your migration will run smoothly.

If mistakes are made, you could create a situation where downtime affects productivity and revenue. The general steps for a smooth migration process are:

  • Migration testing: A small sample size of data should be migrated initially. Administrators can then gain valuable insights into what can be optimised by issues like performance degradation or unforeseen errors. Testing data also helps plan the migration and determine the data necessary for production.
  • Migration security: Data security is essential for governance and compliance. Administrators must implement the proper security in a public cloud because there isn’t a firewall to protect data from external traffic. Cloud providers usually have a “shared responsibility” model where they will only take responsibility for certain security, and the organisation is responsible for proper security configurations and data structures.
  • Staff roles and responsibilities: After migration, administrators must monitor data and potentially add infrastructure in the future. Workloads must be managed and monitored for costs and efficiency. These responsibilities, including security monitoring, must be assigned to specific people within the organisation. Users come and go, and at least one person must disable, enable, and create users and define roles and groups for data access.

Public Cloud Security

The act of migrating sensitive data concerns many organisations. Compliance standards heavily regulate migration and storage of data, and any data breaches could be costly from violations. Before choosing a cloud provider, organisations should review the terms of service for shared responsibilities. The cloud provider will only take responsibility for specific security incidents, many of which do not rely on the organisation’s security configurations.

Security challenges are common in a public cloud because its environment must work seamlessly with the local environment. Data security isn’t always convenient, so it might require users to use two-factor authentication (2FA) or take extra precautions for endpoint security. It’s also challenging to integrate cloud security with current local infrastructure, especially infrastructures with legacy applications. Many cloud security tools work with only the provider’s system, so administrators must ensure that security tools will work with local infrastructure and any internal applications.

Public Cloud Services

Every cloud provider has its own set of tools to help administrators provision, manage, and optimise their environment. Some standard tools are popular with administrators, and the provider chosen should have these tools available. All cloud providers should have a centralised dashboard where customers can scale services up or down, but other tools might be beneficial for cloud management.

A few examples of tools beneficial to administrators:

  • Reports and analytics: Some cloud providers use artificial intelligence to determine where resources can be optimised to reduce costs and improve efficiency and performance.
  • Security infrastructure: Any chosen provider should have tools for identity management, policies, access controls, monitoring, anomaly detection, and intrusion detection.
  • Error tracking: For custom software that runs in the cloud, some cloud providers offer tracing tools to detect runtime errors in real-time and alert administrators and developers.
  • Monitoring and logging: Anomaly detection often requires logging tools to track events and monitor analytics to help administrators make decisions and quickly contain threats.