Ejemplo n.º 1
0
func makeShards(src []*shardSource) ([]*shard.Shard, error) {
	out := make([]*shard.Shard, len(src))
	for i, sh := range src {
		if strings.Index(sh.Pivot, "0x") != 0 {
			return nil, errors.New("invalid pivot format")
		}
		pivot, err := strconv.ParseUint(sh.Pivot[2:], 16, 64)
		if err != nil {
			return nil, err
		}
		out[i] = &shard.Shard{
			Pivot: xor.Key(pivot),
			Addr:  x.Addr(sh.Addr),
			HTTP:  sh.HTTP,
		}
	}
	return out, nil
}
Ejemplo n.º 2
0
// Sum sends a SUM request to the sumr database and returns the value underlying key, or zero otherwise
func (cli *Client) Sum(key sumr.Key) (result float64) {
	cli.lmtr.Open()
	defer cli.lmtr.Close()

	cli.lk.Lock()
	server := cli.metric.Nearest(xor.Key(key), 1)[0].(*shard).Server
	cli.lk.Unlock()

	// Recover from dead shard panic
	defer func() {
		if err := recover(); err != nil {
			log.Printf("dead shard: %s", err)
			result = math.NaN()
		}
	}()

	retrn := server.Call("Sum", key)
	return retrn[0].(float64)
}
Ejemplo n.º 3
0
// Add sends an ADD request to the database to add value to key; if key does not exist, it is created with the given value.
// updateTime is the application-level timestamp of this request.
// Add returns the value of the key after the update.
func (cli *Client) Add(updateTime time.Time, key sumr.Key, value float64) (result float64) {

	// Per-client rate-limiting
	cli.lmtr.Open()
	defer cli.lmtr.Close()

	cli.lk.Lock()
	server := cli.metric.Nearest(xor.Key(key), 1)[0].(*shard).Server
	cli.lk.Unlock()

	// Recover from dead shard panic
	defer func() {
		if err := recover(); err != nil {
			log.Printf("dead shard: %s", err)
			// XXX: Take a more comprehensive action here
			result = math.NaN()
		}
	}()

	retrn := server.Call("Add", updateTime, key, value)
	return retrn[0].(float64)
}
Ejemplo n.º 4
0
func (s *shard) Key() xor.Key {
	return xor.Key(s.ShardKey)
}
Ejemplo n.º 5
0
// ID returns the XOR-metric ID of the shard underlying this checkpoint
func (s *WorkerCheckpoint) Key() xor.Key {
	return xor.Key(s.ShardKey)
}
Ejemplo n.º 6
0
func ShardKeyOf(timedashID int64) xor.Key {
	h := fnv.New64a()
	binary.Write(h, binary.BigEndian, timedashID)
	return xor.Key(h.Sum64())
}
Ejemplo n.º 7
0
func (id SpaceID) ShardKey() xor.Key {
	return xor.Key(id)
}