@@ -126,6 +126,7 @@ type Cluster struct {

 type attacher struct {

 	taskID           string

 	config           *network.NetworkingConfig

+	inProgress       bool

 	attachWaitCh     chan *network.NetworkingConfig

 	attachCompleteCh chan struct{}

 	detachWaitCh     chan struct{}

@@ -81,15 +81,22 @@ func attacherKey(target, containerID string) string {

 // waiter who is trying to start or attach the container to the

 // network.

 func (c *Cluster) UpdateAttachment(target, containerID string, config *network.NetworkingConfig) error {

-	c.mu.RLock()

+	c.mu.Lock()

 	attacher, ok := c.attachers[attacherKey(target, containerID)]

-	c.mu.RUnlock()

 	if !ok || attacher == nil {

+		c.mu.Unlock()

 		return fmt.Errorf("could not find attacher for container %s to network %s", containerID, target)

 	}

+	if attacher.inProgress {

+		logrus.Debugf("Discarding redundant notice of resource allocation on network %s for task id %s", target, attacher.taskID)

+		c.mu.Unlock()

+		return nil

+	}

+	attacher.inProgress = true

+	c.mu.Unlock()

 	attacher.attachWaitCh <- config

-	close(attacher.attachWaitCh)

+

 	return nil

 }