The raise of Hosted Control Plane in Kubernetes

Addressing multicluster with the hyperscaler approach

Transitioning from a single cluster model to a multicluster approach introduces significant complexities. Orchestrating and administering hundreds of Kubernetes clusters demands a scalable, secure, efficient, and cost-effective approach. However, the journey towards adopting multicluster in Kubernetes comes with significant challenges:

• Operational burden: Managing clusters at scale often results in inconsistencies and increased operational effort. For instance, manually upgrading and patching dozens of clusters can exponentially increase errors and team overload.

• Infrastructure Overhead: Each Kubernetes cluster traditionally requires a substantial infrastructure investment, necessitating three or more dedicated machines just for the Control Plane. In a multicluster setup, these requirements multiply, challenging resource allocation and cost management.

• Consistency Across Environments: Achieving uniform configuration and management across different deployment environments (clouds, edge, data centers) requires a concerted effort to ensure that operative procedures are uniformly applied.

• Security and Isolation: In multicluster and multi-tenant environments, robust security and isolation are required. Maintaining these without compromising efficiency poses significant challenges, such as avoiding the noisy-neighbors effect without increase hardware and software costs.

Hyperscalers and other tech giants have long mastered the complexities of running thousands of clusters, utilizing the Hosted Control Plane model to manage scalable, efficient, and secure Kubernetes environments. Unfortunately, their implementations remain closed and proprietary.

Recognizing the success of this approach among hyperscalers, CLASTIX implemented the Hosted Control Plane model in Kamaji, the Open Source Control Plane Manager for Kubernetes. This project allows large enterprises and Managed Service Providers to harness a technology that has been battle-tested in Public Clouds, bringing the same level of scalability, security, and efficiency to a broader array of Kubernetes deployments.

How Hosted Control Plane Works

The Hosted Control Plane architecture enhances Kubernetes cluster management by centralizing control plane components while maintaining the autonomy of individual tenant clusters.  

This setup offers a streamlined, resource-efficient approach to managing multiple tenant clusters.

• Central Management Cluster: This specialized cluster oversees critical components of tenant clusters like the API server, controller manager, and scheduler. Unlike traditional setups where each cluster has its Control Plane dedicated infrastructure, this architecture consolidates these resources, enhancing efficiency and reducing costs.

• Tenant Control Planes: Control Plane components for each tenant cluster are hosted within the management cluster. This arrangement centralizes operations and monitoring while each tenant cluster maintains its distinct infrastructure.

• Datastores: Centralizing the etcd clusters (Kubernetes core data storage component) within the management cluster, either as a shared resource or with dedicated instances per tenant, optimizes performance and isolation.

• Tenant Clusters: Despite a shared management cluster, the architecture ensures rigorous isolation for each tenant's resources, encompassing network, storage, and physical location.

The Hosted Control Plane architecture addresses core scalability, resource management, and security challenges in multicluster and multi-tenant environments by re-architecting the Kubernetes architecture.

Comparison with existing solutions

In the Kubernetes ecosystem, Hosted Control Plane solutions like Kamaji signify a substantial improvement, aligning closely with methods used by hyperscalers and offering distinct benefits over traditional tools like SUSE Rancher or Red Hat ACM:

• Kamaji resembles hyperscaler models in managing Kubernetes services with scalable, flexible, and isolated control planes. This design is critical for efficiently managing large, multi-tenant environments.

• SUSE Rancher/Red Hat ACM are generally effective for regular multicluster management but may not achieve the scalability and flexibility of hyperscaler-inspired solutions, particularly in large-scale, multi-tenant scenarios. Hyperscalers do not use such tools to implement their massive Managed Kubernetes Services.

While tools like SUSE Rancher and Red Hat ACM are still valid for managing multiple Kubernetes clusters, the Hosted Control Plane solutions provide a clever approach that aligns better with the needs of large-scale, multi-tenant, and multicluster Kubernetes environments.

The Business Case for Hosted Control Plane

Adopting Hosted Control Plane solutions, such as Clastix's Kamaji, is more than a technical upgrade; it's a strategic business decision that can significantly impact the economics of Kubernetes operations in multicluster environments.

• Enhanced Productivity: By simplifying cluster provisioning and management, Hosted Control Planes reduce the time DevOps spend on setup and maintenance. Clastix's analysis indicates a potential reduction in provisioning times, translating to over 60% savings in developer efforts.

• Streamlined SRE Operations: Site reliability engineering teams benefit from a unified management approach. This reduces the complexity of handling multiple clusters separately and cuts operational costs by over 65%, per Clastix's findings.

• Energy and Facility Cost Reduction: The centralized nature of Hosted Control Planes leads to fewer physical servers and less energy consumption, slashing power and infrastructure expenses by more than 50%.

• Depreciation Cost Savings: A reduced server footprint also means significant savings in hardware depreciation costs, often exceeding 90%.

Hosted Control Plane solutions offer a path to scalable, efficient Kubernetes management without the proportional cost increase typically associated with multicluster.

The Technical Case for Hosted Control Plane

Here's how Hosted Control Plane architecture enhances Kubernetes:

• Rapid Cluster Provisioning: Provisioning a new cluster becomes as straightforward as deploying worker nodes, significantly reducing setup times. For example, in Kamaji, a Tenant Control Plane is provisioned in just 10 seconds. An entire cluster, just a few minutes, depending on the underlying infrastructure.

• Efficient Cluster Lifecycle Management: Control Planes are managed as workloads within the management cluster. Kubernetes' native automation and self-healing capabilities provide automated updates, certificate renewing, scaling, drift detection, and immediate reconciliation.

• Version Management: The architecture allows different versions of Kubernetes to coexist seamlessly. This flexibility enables applications across various tenants to operate optimally without interdependencies or conflicts.

• Clear Operational Boundaries: Hosted Control Plane architectures distinct boundaries between management and workload operations. This separation simplifies coordination between different teams more straightforwardly.

• Reduction in Human Error: By abstracting Control Plane management and reducing its complexity, the likelihood of human error in provisioning and operations is minimized. This leads to more stable and reliable cluster environments.

• Automation and Autopiloting: The Hosted Control Plane model, managing the control plane as an application, enables advanced automation for routine tasks and autopiloting for self-healing, reducing manual oversight.

• Enhanced Security and Compliance: Network segmentation of tenant clusters is strengthened in this model. The architecture facilitates customized security controls per tenant. This is especially beneficial in complying with specific regulatory requirements for a tenant without impacting other tenants.

Through these technical advantages, Hosted Control Plane solutions like Kamaji streamline Kubernetes management, making clusters at scale more cost-effective, faster to deploy, and scalable, redefining the multi-tenancy boundaries in Kubernetes.

Case Study: Adopt Kamaji for a Managed Kubernetes Service 

As they ventured into Kubernetes, service providers ReeVo, Fastweb, and Netsons, set out to build a scalable Managed Kubernetes Service. However, they faced challenges with the limited scalability of standard enterprise-focused solutions which needed to be simplified and more costly for their needs as Managed Service Providers.

Turning to Kamaji, they found an ideal solution. Kamaji's unique Hosted Control Plane architecture offered the much-needed scalability, cost-effectiveness, and operational simplicity, enabling them to overcome industry hurdles and effectively meet customer requirements.

Their strategic choice of Kamaji marked a significant advancement in delivering innovative, customer-centric, Managed Kubernetes Services for an alternative to hyperscalers.

The Future of Hosted Control Planes in Kubernetes

The journey of adopting the Hosted Control Plane model continues. The future brings even more enhancements as this technology matures and adapts to new challenges and requirements.

The general availability of Kamaji on diverse infrastructures, including OpenStack, vSphere, Equinix, and KubeVirt, is just the beginning. 

As Kubernetes continues to be a foundation technology in the cloud-native landscape, the Hosted Control Plane model will be crucial how organizations deploy, manage, and scale their Kubernetes environments. Solutions like Kamaji are valid and a strategic investment in the future of Kubernetes' infrastructure. As this technology evolves, it will open new doors for operational excellence, innovation, and growth in the cloud-native ecosystem.

Explore the Kamaji project

Experience the hosted control plane technology by exploring the Kamaji project. Engage with the community, contribute to the project, and stay ahead in the cloud-native space. Visit the Kamaji documentation or contact CLASTIX to take your Kubernetes multicluster and multi-tenant infrastructure to the next level.