Kubernetes Multi Master Cluster

Hi All,
Is the Kubernetes multi-master cluster required a minimum of 3 servers?
Kindly explain why need minimum of 3 servers instead of 2.

Thank you in advance.

Thanks and Regards,
Ramesh AR

Hi ramesh.ar16,

A Kubernetes cluster that handles production traffic should have a minimum of three nodes as mentioned in the official docs:

That means a minimum of 3 master nodes per cluster in the high availability clusters.

Kubernetes keeps all critical data in etcd, which uses a majority to repair when there is a fault. An instance of etcd runs on each master node. Three is the minimum number of etcds one wants backing a prod-level cluster. Hence, three is the minimum number of masters per cluster.

Also, because of the leader election. Two masters cannot decide who is a leader will constantly give errors. Three is OK but more is better for redundancy.

But you can have one master node with any number os slaves or workers depending on your system resource capacity.