vitessio/vitess · error

failed to update throttler: %v err: %v

Error message

failed to update throttler: %v err: %v

What it means

UpdateConfiguration wraps any error returned by the individual throttler's own UpdateConfiguration and re-raises it with the throttler name for context. The throttler rejected the supplied configuration.

Source

Thrown at go/vt/throttler/manager.go:158

	return configurations, nil
}

// UpdateConfiguration implements the "Manager" interface.
func (m *managerImpl) UpdateConfiguration(throttlerName string, configuration *throttlerdatapb.Configuration, copyZeroValues bool) ([]string, error) {
	m.mu.Lock()
	defer m.mu.Unlock()

	// Note: The calls to t.UpdateConfiguration() below return no error but the
	// called protobuf library functions may panic. This is fine because the
	// throttler RPC service has a panic handler which will catch this.

	if throttlerName != "" {
		t, ok := m.throttlers[throttlerName]
		if !ok {
			return nil, fmt.Errorf("throttler: %v does not exist", throttlerName)
		}
		if err := t.UpdateConfiguration(configuration, copyZeroValues); err != nil {
			return nil, fmt.Errorf("failed to update throttler: %v err: %v", throttlerName, err)
		}
		return []string{throttlerName}, nil
	}

	for name, t := range m.throttlers {
		if err := t.UpdateConfiguration(configuration, copyZeroValues); err != nil {
			return nil, fmt.Errorf("failed to update throttler: %v err: %v", name, err)
		}
	}
	return m.throttlerNamesLocked(), nil
}

// ResetConfiguration implements the "Manager" interface.
func (m *managerImpl) ResetConfiguration(throttlerName string) ([]string, error) {
	m.mu.Lock()
	defer m.mu.Unlock()

	if throttlerName != "" {

View on GitHub (pinned to 01a25a7d17)

Solutions

1. Read the wrapped err text to see the throttler's validation failure
2. Correct the Configuration values (valid MaxRate >= 0, valid names) and retry
3. If resetting, use ResetConfiguration instead of partial invalid updates
4. Check protobuf field types when constructing throttlerdatapb.Configuration

Example fix

// before
cfg.MaxRate = -5 // invalid
mgr.UpdateConfiguration(ctx, name, cfg, copyZeroValues)
// after
cfg.MaxRate = 0 // 0 means disabled
mgr.UpdateConfiguration(ctx, name, cfg, copyZeroValues)

if cfg.MaxRate < 0 { return errors.New("MaxRate must be >= 0") }
if cfg.Threshold < 0 { return errors.New("Threshold must be >= 0") }
for _, a := range cfg.IgnoreAppNames { if a == "" { return errors.New("empty app name") } }

if _, err := manager.UpdateConfiguration(ctx, name, cfg, copyZeroValues); err != nil {
    if strings.Contains(err.Error(), "failed to update throttler") {
        return fmt.Errorf("invalid throttler config: %w", err)
    }
    return err
}

When it happens

Trigger: Calling Manager.UpdateConfiguration where t.UpdateConfiguration (the per-throttler implementation, e.g. in throttler.go) fails — typically because the Configuration proto contains invalid values (e.g. MaxRate, MaxReplicationLag, IgnoreAppNames constraints) that the throttler validates.

Common situations: Sending a ThrottlerUpdateConfiguration RPC with an out-of-range max rate or malformed app-name list; the underlying throttler rejects it and the manager wraps the cause.

Related errors

• no app indicated
• failed to instantiate throttler: %v
• malformed spec: doesn't define a range: %q
• conflicting entries: %q overlaps with %q
• throttler: %v does not exist

AI-assisted analysis of vitessio/vitess@01a25a7d17 (2026-09-01). Data as JSON: /api/errors/c0c2e490abb5224e. Report an issue: GitHub.