1.3.1 Maintaining a quorum
To ensure smooth functioning of service and cluster-level operations, a quorum of cluster nodes must be running at all times. A quorum means that more than half (50% + 1) of the nodes need to be running and communicating with each other at any given moment.
Your cluster should always be designed and built to contain anodd number of nodes, which helps to maintain a quorum in both normal and adverse networking conditions. Keep this in mind when planning your deployment and looking ahead to maintaining your cluster.
|
# of nodes in cluster |
# of nodes required for a quorum |
|---|---|
|
2 |
2 |
|
5 |
3 |
|
n |
(n / 2) + 1 |