Method ForEachSlave

osscluster.go:1381–1415

ForEachSlave concurrently calls the fn on each slave node in the cluster. It returns the first error if any.

(
	ctx context.Context,
	fn func(ctx context.Context, client *Client) error,
)

// ForEachSlave concurrently calls the fn on each slave node in the cluster.
// It returns the first error if any.
func (c *ClusterClient) ForEachSlave(
	ctx context.Context,
	fn func(ctx context.Context, client *Client) error,
) error {
	state, err := c.state.ReloadOrGet(ctx)
	if err != nil {
		return err
	}

	var wg sync.WaitGroup
	errCh := make(chan error, 1)

	for _, slave := range state.Slaves {
		wg.Add(1)
		go func(node *clusterNode) {
			defer wg.Done()
			err := fn(ctx, node.Client)
			if err != nil {
				select {
				case errCh <- err:
				default:
				}
			}
		}(slave)
	}

	wg.Wait()

	select {
	case err := <-errCh:
		return err
	default:
		return nil
	}
}

// ForEachShard concurrently calls the fn on each known node in the cluster.
// It returns the first error if any.