hashicorp/nomad · error

all servers must have raft_protocol set to 3 or higher to us

Error message

all servers must have raft_protocol set to 3 or higher to use this endpoint

What it means

ServerHealth rejected the request because the minimum Raft protocol version in the cluster is below 3; the health endpoint relies on features that require raft_protocol 3+ on every server.

Source

Thrown at nomad/operator_endpoint.go:409

	if authErr != nil {
		return structs.ErrPermissionDenied
	}

	// This action requires operator read access.
	aclObj, err := op.srv.ResolveACL(args)
	if err != nil {
		return err
	} else if !aclObj.AllowOperatorRead() {
		return structs.ErrPermissionDenied
	}

	// Exit early if the min Raft version is too low
	minRaftProtocol, err := op.srv.MinRaftProtocol()
	if err != nil {
		return fmt.Errorf("error getting server raft protocol versions: %s", err)
	}
	if minRaftProtocol < 3 {
		return fmt.Errorf("all servers must have raft_protocol set to 3 or higher to use this endpoint")
	}

	*reply = *op.srv.GetClusterHealth()

	return nil
}

// SchedulerSetConfiguration is used to set the current Scheduler configuration.
func (op *Operator) SchedulerSetConfiguration(args *structs.SchedulerSetConfigRequest, reply *structs.SchedulerSetConfigurationResponse) error {

	authErr := op.srv.Authenticate(op.ctx, args)
	if done, err := op.srv.forward("Operator.SchedulerSetConfiguration", args, args, reply); done {
		return err
	}
	op.srv.MeasureRPCRate("operator", structs.RateMetricWrite, args)
	if authErr != nil {
		return structs.ErrPermissionDenied
	}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Upgrade all servers so raft_protocol is 3 or higher
2. Set `raft_protocol = 3` in server configs where applicable and restart
3. Retry once the peers cache reflects the upgraded protocol versions

When it happens

Trigger: Thrown at nomad/operator_endpoint.go:409 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/852467f7cacb61a5. Report an issue: GitHub.