Kubernetes: On-prem vs Managed

Kubernetes is an open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It is being widely adopted across enterprises due to its ability to handle complex, distributed workloads, increase resource efficiency, and provide seamless scalability. Major organizations globally are leveraging k8 to manage their cloud-native applications and infrastructure, making it a cornerstone technology in modern IT and DevOps strategies. Its adoption has surged over the past few years, with 96% of organizations using or evaluating Kubernetes as part of their cloud-native strategy, according to CNCF’s 2023 report: https://www.cncf.io/reports/cncf-annual-survey-2021/

The best Kubernetes architecture and deployment model for your organization depends on your needs and goals. How do you know which option is best for you between on-prem vs managed k8?

On-Premises Kubernetes:

Think of on-premises Kubernetes like building and maintaining your own custom gaming PC. When you build your own PC:

1. Initial Setup and Investment: You choose every part — CPU, GPU, RAM, case, etc. — and assemble the system yourself, which can be both time-consuming and expensive.
2. Ongoing Maintenance: You handle all the upgrades, repairs, and optimizations, from installing new drivers to replacing parts as they wear out.
3. Full Customization: You have the freedom to overclock, upgrade components, and tweak settings to optimize performance exactly how you like it.
4. Cost Efficiency: While there are higher upfront costs for the parts, over time, you avoid the subscription fees associated with cloud gaming services or renting gaming PCs.

In the same way, with on-premises Kubernetes:

• Infrastructure Ownership: You own the servers and hardware necessary to run Kubernetes and are responsible for purchasing and setting them up.
• Full Customization: You have total control over your Kubernetes environment, allowing you to configure and optimize it to your exact needs.
• Self-Maintenance: Just like keeping your PC in top shape, you must handle patches, updates, and monitoring yourself, requiring in-house expertise.
• Cost Structure: Significant initial investments but lower ongoing operational costs compared to cloud services.

Managed Kubernetes:

Managed Kubernetes is like using a gaming console:

1. Ready to Play: You purchase a console, plug it in, and start gaming. The console manufacturer handles all the internal setup, so you don’t need to worry about choosing components or dealing with compatibility issues.
2. Maintenance-Free: The console company manages all the updates, software patches, and performance optimizations. If a problem arises, they fix it for you or replace faulty units.
3. Convenience: You don’t have to worry about the technical details; the system is ready to go, and you can focus on gaming rather than maintaining hardware or tweaking settings.
4. Subscription Costs: You may pay a recurring fee for online services or cloud-based gaming, but everything is managed for you.

Managed Kubernetes operates similarly:

• Cloud Provider: A cloud provider like GKE, EKS, or AKS manages the infrastructure for you.
• Hassle-Free: Just like with a gaming console, the provider handles all setup, updates, and maintenance, allowing you to focus on deploying your applications.
• No Maintenance: The provider ensures your system is running smoothly with regular updates and patches, minimizing the need for in-house Kubernetes expertise.
• Usage-Based Costs: You pay for the cloud service based on usage, similar to subscription fees, but without needing to manage hardware or complex systems.

Which One is Best for You?

• If you like complete control and tweaking every aspect of your system (like with a custom-built PC), on-premises Kubernetes gives you that level of flexibility.
• If you prefer convenience and don’t want to worry about the technical intricacies (like with a gaming console), managed Kubernetes is the way to go.

Having implemented both k8 deployment models, I faced the following challenges with on-prem:

• Load Balancing: Load balancing is essential for both your Kubernetes cluster master nodes and the application services deployed within your clusters. Ensuring proper load balancing optimizes performance and helps manage traffic efficiently, avoiding bottlenecks and improving availability.
• High Availability: To ensure your Kubernetes infrastructure is resilient and can handle infrastructure or data center failures, it’s important to implement high availability (HA). This involves deploying multiple master nodes per cluster and, when necessary, utilizing multiple Kubernetes clusters spread across different availability zones. However, moving Persistent Volumes (PVs) across zones can pose challenges, so careful planning is required.
• Auto-scaling: Kubernetes’ built-in auto-scaling has limitations, but newer tools like Karpenter can address these. However, Karpenter is not yet fully supported across all major cloud providers, so auto-scaling solutions may vary depending on your environment.
• Persistent Storage: For production workloads, persistent storage — such as block or file storage — is often required. Most enterprise storage vendors now offer CSI (Container Storage Interface) plugins for Kubernetes, allowing seamless integration with existing storage solutions. It’s critical to work with your storage vendor to identify and install the appropriate plugin for your on-premises Kubernetes deployment.
• Cluster Upgrades: Kubernetes clusters need to be upgraded approximately every 3–9 months when new upstream versions are released. These upgrades can potentially cause issues if there are API incompatibilities, so careful testing and planning are essential before upgrading.
• Monitoring: Effective monitoring is vital for managing Kubernetes clusters. Tools like Datadog or open-source options like Prometheus and Grafana can be used to monitor your Kubernetes environment. Choosing the right tool will depend on your existing infrastructure and the specific needs of your Kubernetes deployment.