Example #1
0
func newRegionLeader(lockNode string) *regionLeader {
	rl := &regionLeader{
		active:    true,
		lockNode:  lockNode,
		rescinded: make(chan struct{}),
	}
	// establish a watch to cleanup
	go func() {
		_, _, watch, err := zookeeper.GetW(rl.lockNode)
		if err != nil {
			rl.Rescind()
			return
		}
		<-watch
		log.Debugf("[Sync:RegionLeader] Watch triggered on '%v', will rescind leadership", rl.lockNode)
		inst.Counter(1.0, "sync.regionleader.remotely-rescinded")
		rl.Rescind()
		return
	}()

	// Register region leader
	mu.Lock()
	rls = append(rls, rl)
	mu.Unlock()

	return rl
}
Example #2
0
func waitForWinner(path, ourNode string) error {
	seq, err := parseSeq(ourNode)
	if err != nil {
		return err
	}

	for {
		lowestSeq, prevSeqPath, err := findLowestSequenceNode(path, seq)
		if err != nil {
			return err
		}

		if seq == lowestSeq {
			// we are now the leader!
			break
		}

		// wait on the node next in line for the lock
		_, _, ch, err := zookeeper.GetW(path + "/" + prevSeqPath)
		if err != nil && err != gozk.ErrNoNode {
			return err
		} else if err != nil && err == gozk.ErrNoNode {
			// try again
			continue
		}

		ev := <-ch
		if ev.Err != nil {
			return ev.Err
		}
	}

	return nil
}