redis/go-redis · error

failed to enable maintnotifications: server does not support

Error message

failed to enable maintnotifications: server does not support RESP3 (HELLO command failed)

What it means

Error "failed to enable maintnotifications: server does not support RESP3 (HELLO command failed)" thrown in redis/go-redis.

Source

Thrown at redis.go:1044

		endpointType = c.opt.MaintNotificationsConfig.EndpointType
		maintNotifMode = c.opt.MaintNotificationsConfig.Mode
	}
	c.optLock.RUnlock()

	// Maintenance notifications require RESP3 push frames. If HELLO failed
	// and the connection fell back to RESP2, there is no point in sending
	// CLIENT MAINT_NOTIFICATIONS: the server either rejects it (making the
	// error misleading) or accepts it silently, leaving the client unable
	// to receive any notifications. Decide based on the actual negotiated
	// protocol rather than the requested one.
	if maintNotifEnabled && protocol == 3 && !helloOK {
		if maintNotifMode == maintnotifications.ModeEnabled {
			// Explicitly requested - fail fast with a clear reason.
			cn.GetStateMachine().Transition(pool.StateClosed)
			if errorCallback := pool.GetMetricErrorCallback(); errorCallback != nil {
				errorCallback(ctx, "HANDSHAKE_FAILED", cn, "HANDSHAKE_FAILED", true, 0)
			}
			return fmt.Errorf("failed to enable maintnotifications: server does not support RESP3 (HELLO command failed)")
		}
		// auto/other modes: silently disable maintnotifications for this client.
		c.optLock.Lock()
		c.opt.MaintNotificationsConfig.Mode = maintnotifications.ModeDisabled
		c.optLock.Unlock()
		if err := c.disableMaintNotificationsUpgrades(); err != nil {
			internal.Logger.Printf(ctx, "failed to disable maintnotifications in auto mode: %v", err)
		}
		maintNotifEnabled = false
	}

	var maintNotifHandshakeErr error
	if maintNotifEnabled && protocol == 3 {
		// Hold the manager read lock across the handshake and tracking so a
		// concurrent downgrade cannot remove pool-level listeners before a
		// successfully enabled connection is tracked for retirement.
		c.maintNotificationsManagerLock.RLock()
		manager := c.maintNotificationsManager

View on GitHub (pinned to c5cad058c7)

When it happens

Trigger: Thrown at redis.go:1044 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of redis/go-redis@c5cad058c7 (2026-09-01). Data as JSON: /api/errors/39d2582f412ccc28. Report an issue: GitHub.