hashicorp/nomad · error

node event must not be set

Error message

node event must not be set

What it means

Guard in Node.UpdateDrain: the request sets a NodeEvent, but drain updates must not carry node events — events are generated server-side and would be duplicated via this write path.

Source

Thrown at nomad/node_endpoint.go:929

	n.srv.MeasureRPCRate("node", structs.RateMetricWrite, args)
	if authErr != nil {
		return structs.ErrPermissionDenied
	}
	defer metrics.MeasureSince([]string{"nomad", "client", "update_drain"}, time.Now())

	// Check node write permissions
	if aclObj, err := n.srv.ResolveACL(args); err != nil {
		return err
	} else if err := n.checkNodeDrainAuth(aclObj, args); err != nil {
		return err
	}

	// Verify the arguments
	if args.NodeID == "" {
		return fmt.Errorf("missing node ID for drain update")
	}
	if args.NodeEvent != nil {
		return fmt.Errorf("node event must not be set")
	}

	// The AuthenticatedIdentity is unexported so won't be written via
	// Raft. Record the identity string so it can be written to LastDrain
	args.UpdatedBy = args.GetIdentity().String()

	snap, err := n.srv.fsm.State().Snapshot()
	if err != nil {
		return err
	}
	node, err := snap.NodeByID(nil, args.NodeID)
	if err != nil {
		return err
	}
	if node == nil {
		return fmt.Errorf("node not found")
	}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Send the drain request without NodeEvent populated

When it happens

Trigger: Thrown at nomad/node_endpoint.go:929 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/2e271bdb1a6c71c6. Report an issue: GitHub.