Call us
Designing

The Ultimate Kubernetes Checklist to Set Up High Availability

"Establish high availability in Kubernetes with Cpluz's expert guide. Download the ultimate checklist for scalable and fault-tolerant deployments today."

4 min readCpluz

The Ultimate Kubernetes Checklist to Set Up High Availability

In order to build scalable and fault-tolerant applications in 2025, container orchestration tools like Kubernetes have become essential. Kubernetes enables the deployment, scaling, and management of containers that run on various hosts. High availability is crucial in any distributed system, ensuring that when a node or a host goes down, the system remains functional. A well-implemented high availability strategy can significantly reduce the likelihood of downtime and improve overall application performance. In this article, we'll provide a comprehensive Kubernetes checklist to set up high availability.

1. Design a Suitable Cluster Architecture

Ensuring high availability starts with the design of your Kubernetes cluster. You need to choose the right combination of worker nodes, control planes, and storage solutions to build a resilient system. A multi-master architecture, where all control plane nodes act as both masters and etcd serve as a distributed key-value store, allows you to maintain the control plane's high availability. Distributing etcd across multiple nodes makes the entire system more resilient. Moreover, you should create separate resource pools for control plane and worker nodes.

Key Considerations:

  • Rack-aware topologies
  • Affinity and anti-affinity rules
  • Distributed etcd
  • Create separate resource pools

2. Utilize Kubernetes Scheduler Extensions

The Kubernetes scheduler extends the previous point as it ensures efficient and effective node resource allocation. Kubernetes plugins such as Topology Aware Horizontal Pod Autoscaling, Cloud-Local, and Node-Local can be used to develop high availability strategies. These plugins take into account the resource requirements and constraints while allocating pods.

Key Considerations:

  • Topology Aware Horizontal Pod Autoscaling
  • Cloud-Local and Node-Local
  • Resource constraints and pod requirements

3. Ensure SDS (Software Defined Storage) for Highly Available Storage Requirements

High availability is also linked with data durability and storage availability. Kubernetes supports various storage solutions like Local Storage, Persistent Volumes, and Network Attaches. Persistent Volumes use StorageClass to configure the specific storage settings according to the needs of your applications. In multi-site clusters, ensure that StorageClass is updated to match the datacenter separation, for example, by utilizing different storage providers, especially for log database structures, or leveraging File System replication.

Key Considerations:

  • Local Storage
  • Persistent Volumes and StorageClass
  • Multi-site clusters
  • Data replication for datacenter separation

4. Utilize RGW (Rados Gateway) for Cloud Provider Integration

Kubernetes provides integration with various cloud infrastructure using different cloud-provider backends, for example, AWS, GCE, Azure. These integrations provide automated provisioning and self-healing clusters. To further increase cluster reliability, ensure usage of RGW with Ceph Storage. This is especially useful for applications requiring external cloud connectivity or RunTime storage. RGW can be used to expose Swift, S3, and OpenStack Manila through block, object, and share storage types.

Key Considerations:

  • RGW for cloud provider integration
  • Swift, S3, and OpenStack Manila
  • Block, Object, and Share Storage types

5. Implement PodDisruptionBudget

For applications with high availability goals, Apex, Iterate, and Scale, a satisfactory service level agreement can only be achieved when the cluster operation does not involve taking down all replicas at once. To ensure that cluster operations do not disrupt more than a specified fraction of currently running replicas at any given time, Kubernetes provides the PodDisruptionBudget mechanism. PDB allow applications to specify the conditions under which pods can be evicted, which can include factors such as replica counts, resource requirements, and node characteristics.

Key Considerations:

  • PodDisruptionBudget (PDB)
  • Conditions for pod eviction
  • Replica counts and resource requirements
  • Node characteristics

6. Use ReplicaSets or StatefulSets for Highly Available Applications

A ReplicaSet ensures that a specified number of replicas of a pod are running at any given time. StatefulSets work similarly, ensuring a sequence of stateful applications maintains their identities. By defining the desired number of replicas for a set, any involuntary or necessary pod deletion can be mitigated, leading to a more robust and fault-tolerant cluster.

Key Considerations:

  • ReplicaSets
  • StatefulSets
  • Desired replica counts
  • Application identities

By following this ultimate Kubernetes checklist, you can build a fault-tolerant and highly available cluster, ensure your distributed system runs smoothly in any scenario, and protect your business from downtime and lost revenue.

Contact Cpluz at info@cpluz.com or visit cpluz.com for professional Kubernetes deployment and high availability solutions.