Example #1
0
func readDatabase() (Database, error) {
	kvdb := kvdb.Instance()

	db := Database{
		Status:      api.Status_STATUS_INIT,
		NodeEntries: make(map[string]NodeEntry),
	}

	kv, err := kvdb.Get(ClusterDBKey)
	if err != nil && !strings.Contains(err.Error(), "Key not found") {
		dlog.Warnln("Warning, could not read cluster database")
		return db, err
	}

	if kv == nil || bytes.Compare(kv.Value, []byte("{}")) == 0 {
		dlog.Infoln("Cluster is uninitialized...")
		return db, nil
	}
	if err := json.Unmarshal(kv.Value, &db); err != nil {
		dlog.Warnln("Fatal, Could not parse cluster database ", kv)
		return db, err
	}

	return db, nil
}
Example #2
0
func writeDatabase(db *Database) error {
	kvdb := kvdb.Instance()
	b, err := json.Marshal(db)
	if err != nil {
		dlog.Warnf("Fatal, Could not marshal cluster database to JSON: %v", err)
		return err
	}

	if _, err := kvdb.Put(ClusterDBKey, b, 0); err != nil {
		dlog.Warnf("Fatal, Could not marshal cluster database to JSON: %v", err)
		return err
	}

	dlog.Infoln("Cluster database updated.")
	return nil
}
Example #3
0
func (c *ClusterManager) Start() error {
	dlog.Infoln("Cluster manager starting...")

	c.gEnabled = true
	c.selfNode = api.Node{}
	c.selfNode.GenNumber = uint64(time.Now().UnixNano())
	c.selfNode.Id = c.config.NodeId
	c.selfNode.Status = api.Status_STATUS_OK
	c.selfNode.MgmtIp, c.selfNode.DataIp, _ = ExternalIp(&c.config)
	c.selfNode.NodeData = make(map[string]interface{})
	c.system = systemutils.New()

	// Start the gossip protocol.
	// XXX Make the port configurable.
	gob.Register(api.Node{})
	c.gossip = gossip.New("0.0.0.0:9002", types.NodeId(c.config.NodeId),
		c.selfNode.GenNumber)
	c.gossip.SetGossipInterval(2 * time.Second)

	kvdb := kvdb.Instance()
	kvlock, err := kvdb.Lock(clusterLockKey, 60)
	if err != nil {
		dlog.Panicln("Fatal, Unable to obtain cluster lock.", err)
	}
	defer kvdb.Unlock(kvlock)

	db, err := readDatabase()
	if err != nil {
		dlog.Panicln(err)
	}

	// Cluster database max size... 0 if unlimited.
	c.size = db.Size

	if db.Status == api.Status_STATUS_INIT {
		dlog.Infoln("Will initialize a new cluster.")

		c.status = api.Status_STATUS_OK
		db.Status = api.Status_STATUS_OK
		self, _ := c.initNode(&db)

		err = c.initCluster(&db, self, false)
		if err != nil {
			dlog.Errorln("Failed to initialize the cluster.", err)
			return err
		}

		// Update the new state of the cluster in the KV Database
		err := writeDatabase(&db)
		if err != nil {
			dlog.Errorln("Failed to save the database.", err)
			return err
		}

	} else if db.Status&api.Status_STATUS_OK > 0 {
		dlog.Infoln("Cluster state is OK... Joining the cluster.")

		c.status = api.Status_STATUS_OK
		self, exist := c.initNode(&db)

		err = c.joinCluster(&db, self, exist)
		if err != nil {
			dlog.Errorln("Failed to join cluster.", err)
			return err
		}

		err := writeDatabase(&db)
		if err != nil {
			return err
		}

	} else {
		return errors.New("Fatal, Cluster is in an unexpected state.")
	}

	// Start heartbeating to other nodes.
	go c.startHeartBeat()
	go c.updateClusterStatus()

	kvdb.WatchKey(ClusterDBKey, 0, nil, c.watchDB)

	return nil
}