Designing a Multitenancy Kubernetes Strategy that Fits Your Organization

While it is projected that production projects using Kubernetes will rise 61% in the next two years, nearly all organizations (94%) run into challenges. Many organizations begin adopting Kubernetes without a dedicated management strategy. Individual teams create their own clusters to meet specific business functions, but there is no consistent structure, policy or management practice across the enterprise. As the number of clusters and workloads grow, they are often managed and governed independently, creating cluster sprawl that prevents organizations from realizing the full value of containers and Kubernetes. This chaotic environment is rife with redundant efforts and wasted resources.

One way to help address this challenge while simultaneously improving the return on investment is by creating a multi-tenancy Kubernetes strategy. Running more applications on the same shared infrastructure means better utilization of resources and a reduction in overall operating costs.

Benefits of a Successful Multitenancy Strategy

Whether you are new to Kubernetes or your organization has adopted Kubernetes in many clusters, a multi-tenancy strategy can provide significant benefits.

1. Improved ROI: A strong management and multitenancy strategy can lead to drastically reduced IT investments in order to improve ROI. Larger, shared clusters reduce infrastructure overhead by enabling more efficient use of shared resources and reducing operating costs. Management is simplified by applying a consistent configuration strategy and applications can be made more resilient to infrastructure failures, resulting in fewer application outages over time. In other words, a correct multitenant strategy enables you to extract more use from existing IT assets from both an infrastructure and operating cost perspective.
2. Strict and Robust Workload Isolation: Kubernetes achieves multitenancy by facilitating software-layer isolation on shared infrastructure. Some of the key multitenancy capabilities in Kubernetes that provide this isolation are namespaces, roles and role bindings, resource quotas, and network policies. Use of these software constructs should be reinforced with correct organizational models and cultures, ones that align technical capabilities with business goals. Among the benefits provided by this level of isolation are mitigation of “noisy neighbor” issues, as well as increased ability to allocate and track resources by application, project, or team
3. Increased Ability to Scale Applications: Most applications exhibit “bursty” consumption of CPU and memory resources, with these bursts occurring at different times. With a multitenant configuration, it is possible to ensure sufficient resources for all applications by clever sharing of resources, rather than simply adding up the maximum resource requirements for all the applications.

Challenges of Managing Multitenancy Deployments

One very common problem when managing a multitenancy Kubernetes deployment is the “noisy neighbor.” A noisy neighbor is defined as one party hogging shared resources in a multitenant environment — an issue that has become commonplace for IT teams.

Noisy neighbors have a severe impact on the performance of other workloads on the same cluster, sometimes preventing them from running altogether. When one application is sucking up all of the CPU or memory in a cluster, other workloads run slowly, if at all. The chronic lack of visibility into containers, coupled with a lack of uniform policies, means IT operations and technical teams may not be able to prevent a noisy neighbor issue in a multitenant environment before it happens and may be hard-pressed to mitigate it once it does.

The central element of isolation in Kubernetes is a namespace. Namespaces are the declarative regions that help organize where code runs. Proper use of namespaces can help troubleshoot and prevent noisy neighbors. Typically, every tenant — usually an application or microservice, though it can be a team or project — on a platform needs a single, dedicated namespace. Applications deployed in a namespace can leverage the powerful security and resource management constructs that Kubernetes offers to build an effective multitenant platform.

Any Good Strategy Includes Risk Management

It is critical in any strategy to consider risk domains from a business perspective. This perspective includes regulatory environments, compliance objectives, and other business requirements that vary according to workload. In many organizations, these requirements justify organizing clusters according to each risk domain so that workloads can be deployed with automated controls that enforce the appropriate policy.

For example, it may be beneficial to have several clusters arranged by certain industry-specific regulations or data laws. In a proper multitenancy strategy, it’s important to arrange clusters to represent specific risk domains and to provide automatic enforcement of the required configuration for each workload to be applied at the cluster level. Then, applications can rely on the cluster infrastructure to provide these capabilities, rather than each application itself having to reinvent such enforcement independently.

As Kubernetes environments grow, so does their complexity. By stepping back and creating a streamlined multitenancy strategy, organizations can customize deployments to meet both their IT and business requirements. Through a proper strategy, any organization can optimize efforts for savings, reduce risks and increase security — regardless of the number or size of your clusters.