Min Master Node Less Than Quorum
The minimum_master_nodes setting is lower than a safe majority of master-eligible nodes. That increases split-brain risk if parts of the cluster partition and form separate clusters.
For a complete list of insights, refer to AutoOps insights.
| Field | Value |
|---|---|
| Component | Elasticsearch |
| Severity | High |
| Scope | Cluster |
| Domains | configuration, high-availability, stability |
The following is an example of what you might see when this insight is triggered. Real insights use live data and links from your deployment or cluster.
Number of nodes with the master role: 12.
Minimum master nodes current settings: es-data-01
AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
Set minimum master nodes quorum
Condition: Always shown for this insight.
Set discovery.zen.minimum_master_nodes to 2 in each node's config, then rolling-restart master-eligible nodes so the quorum takes effect.
Impact: The cluster is at risk of splitting into multiple clusters — split brain. This could cause data loss and data corruption. The value in this setting should be 50% of the number of master eligible nodes rounded up to the nearest integer. If it is not set correctly, nodes could form a separate cluster independent of the primary cluster if they disconnect from it for any reason.