High availability cluster setup in Kubernetes - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a high availability (HA) cluster in Kubernetes?

A high availability cluster in Kubernetes is a setup where multiple master nodes run simultaneously to ensure the cluster remains operational even if one or more masters fail.

beginner

Why do we use multiple master nodes in an HA Kubernetes cluster?

Multiple master nodes provide redundancy. If one master node fails, others continue managing the cluster, preventing downtime.

intermediate

What role does etcd play in a Kubernetes HA cluster?

etcd stores the cluster's configuration and state data. In HA, etcd runs as a cluster itself to keep data consistent and available across master nodes.

intermediate

How does a load balancer contribute to a Kubernetes HA cluster?

A load balancer distributes requests to the multiple master nodes, ensuring traffic is balanced and the cluster remains reachable even if one master fails.

beginner

Name one common tool or method to set up a Kubernetes HA cluster.

Using kubeadm with multiple control plane nodes and an external load balancer is a common method to set up a Kubernetes HA cluster.

What is the main purpose of having multiple master nodes in a Kubernetes HA cluster?

A To speed up container image downloads

B To increase the number of worker nodes

C To reduce the number of pods running

D To provide redundancy and avoid single points of failure

Multiple master nodes ensure the cluster control plane stays available if one master fails.

Which component stores the cluster state in a Kubernetes HA setup?

A kubelet

B etcd

C kube-proxy

D container runtime

etcd is the key-value store that holds the cluster's state and configuration.

What is the role of a load balancer in a Kubernetes HA cluster?

A To distribute requests to multiple master nodes

B To balance traffic between worker nodes

C To store container images

D To monitor pod health

The load balancer directs API requests to available master nodes to maintain availability.

Which command-line tool is commonly used to initialize a Kubernetes HA cluster?

A kubectl

B docker

C kubeadm

D helm

kubeadm is used to bootstrap Kubernetes clusters, including HA setups.

In a Kubernetes HA cluster, what happens if one master node goes down?

A The cluster continues running using other master nodes

B All pods are deleted

C The entire cluster stops working

D Worker nodes shut down automatically

Other master nodes take over control to keep the cluster operational.

Explain the key components and their roles in a Kubernetes high availability cluster setup.

Think about how the cluster stays up if one part fails.

Describe the steps to set up a basic Kubernetes HA cluster using kubeadm.

Focus on the order and components involved.