Private vs. Public vs. Hybrid Cloud: Which One to Choose?
What cloud is right for you?
Many IT departments now manage applications across multiple environments in a complex overall IT architecture. They also must constantly re-evaluate their unique mix of on-premises, private cloud and public cloud infrastructure to meet new business goals and determine how applications can be migrated to the public cloud in a cost-effective way.
Applications built at different times, in different languages, and by different teams need to be evaluated for migration to the cloud, which often requires deep knowledge of the existing IT infrastructure as well as the public cloud resources that could replace these functions.
Ultimately, managers must determine the hosting solution that suits each application: on-premises, private cloud, public cloud, or hybrid cloud. Below we outline some basic considerations and cloud comparisons, as well as best practices for how to integrate and manage these complex deployments.
By now, most organisations understand the cost and benefits of an IaaS provider like Amazon Web Services, including unpredictable cost of ownership and a shift from a capital expenditure to an operating expenditure.
Technical benefits can be perceived as attractive: scalability, automated deployments, and greater reliability. There are few technical limitations that would prevent an organisation from moving their infrastructure to AWS; almost every function a traditional resource supports in the private cloud or in a datacenter could be replicated in AWS.
Enterprises must then decide whether they want to manage their public cloud infrastructure themselves or outsource it to a managed cloud services provider. A managed cloud services provider can maintain the entire cloud infrastructure (web servers, application servers, load balancing, custom failover scripts) and some may also be able to integrate with on-premises or private cloud solutions to provide a single monitoring interface.
Note that compliance requirements no longer necessitate a private cloud solution rather than a public cloud solution. AWS has been on the leading edge of compliance in the cloud for several years, and while there is lingering skepticism, the adoption of AWS cloud by the largest and most complex healthcare and financial institutions is an indication of the degree to which AWS ensures compliance and security in the cloud, yet many Private Cloud Providers can also meet the scalability, complexity and security of Public Cloud so can be a very good choice where Data Sovereignty is a matter of concern for your organisation.
Logistically, it is often much simpler to move from your on-premises environment to a private cloud than from on-premises to public cloud.
Private cloud environments can be configured to support any application, just as your datacenter currently hosts it. Private cloud is an especially attractive option if certain features in legacy applications prevent some applications from operating well in the public cloud.
Here are some indicators that your application would be a good candidate for maintenance in a private cloud:
- You are using Oracle shared storage and require dedicated infrastructure for compliance. The shared storage equivalent in AWS, RDS, is not HIPAA-compliant.
- You need high performance access to a file system.
- An application is aged or infrequently used, therefore not worth the effort of migrating to the public cloud.
- The application has very predictable usage patterns and benefits from low storage costs.
A private cloud solution can be implemented in your on-premises datacenter with a virtualisation layer such as VMware or Microsoft Hyper-V, though many mid-sized and large enterprises let a managed private cloud services provider maintain servers, storage, network, and application infrastructure.
Ninety percent (90%) of companies state they are going to pursue a hybrid cloud solution this year.
IT Architecture is often complex, meaning that a hybrid cloud solution — where public, private or on-premises infrastructure supports a single application — is the best solution.
Hybrid architectures are especially attractive for organisations that want to explore the flexibility and scalability of the cloud.
A hybrid system is also a good solution if there is institutional hesitancy about the security of the public cloud for sensitive data. Often easier to convince internal executive or IT teams to experiment with private cloud solutions rather than adopt them wholesale. Which maintains IT staff and legacy applications on legacy infrastructure while opening new lines of business in the cloud is a cost-effective solution that also manages institutional risk.
Finally, an important thing to understand about hybrid environments is that they are only as strong as the integrations that unite them. Performance monitoring, regular testing, and data ingress and egress procedures will reveal future areas of difficulty as well as signal when and how to further evolve the application.