Golang errors.Trace函数代码示例

func GetRedisStat(addr, passwd string) (map[string]string, error) {
	c, err := DialTo(addr, passwd)
	if err != nil {
		return nil, err
	}
	defer c.Close()

	ret, err := redis.String(c.Do("INFO"))
	if err != nil {
		return nil, errors.Trace(err)
	}
	m := make(map[string]string)
	lines := strings.Split(ret, "\n")
	for _, line := range lines {
		kv := strings.SplitN(line, ":", 2)
		if len(kv) == 2 {
			k, v := strings.TrimSpace(kv[0]), strings.TrimSpace(kv[1])
			m[k] = v
		}
	}

	reply, err := redis.Strings(c.Do("config", "get", "maxmemory"))
	if err != nil {
		return nil, errors.Trace(err)
	}
	// we got result
	if len(reply) == 2 {
		if reply[1] != "0" {
			m["maxmemory"] = reply[1]
		} else {
			m["maxmemory"] = "∞"
		}
	}
	return m, nil
}

func WaitForReceiverWithTimeout(zkConn zkhelper.Conn, productName string, actionZkPath string, proxies []ProxyInfo, timeoutInMs int) error {
	if len(proxies) == 0 {
		return nil
	}

	times := 0
	proxyIds := make(map[string]struct{})
	var offlineProxyIds []string
	for _, p := range proxies {
		proxyIds[p.Id] = struct{}{}
	}

	checkTimes := timeoutInMs / 500
	// check every 500ms
	for times < checkTimes {
		if times >= 6 && (times*500)%1000 == 0 {
			log.Warnf("abnormal waiting time for receivers: %s %v", actionZkPath, offlineProxyIds)
		}
		// get confirm ids
		nodes, _, err := zkConn.Children(actionZkPath)
		if err != nil {
			return errors.Trace(err)
		}
		confirmIds := make(map[string]struct{})
		for _, node := range nodes {
			id := path.Base(node)
			confirmIds[id] = struct{}{}
		}
		if len(confirmIds) != 0 {
			match := true
			// check if all proxy have responsed
			var notMatchList []string
			for id, _ := range proxyIds {
				// if proxy id not in confirm ids, means someone didn't response
				if _, ok := confirmIds[id]; !ok {
					match = false
					notMatchList = append(notMatchList, id)
				}
			}
			if match {
				return nil
			}
			offlineProxyIds = notMatchList
		}
		times += 1
		time.Sleep(500 * time.Millisecond)
	}
	if len(offlineProxyIds) > 0 {
		log.Errorf("proxies didn't responed: %v", offlineProxyIds)
	}

	// set offline proxies
	for _, id := range offlineProxyIds {
		log.Errorf("mark proxy %s to PROXY_STATE_MARK_OFFLINE", id)
		if err := SetProxyStatus(zkConn, productName, id, PROXY_STATE_MARK_OFFLINE); err != nil {
			return errors.Trace(err)
		}
	}
	return errors.Trace(ErrReceiverTimeout)
}

func (self *ServerGroup) RemoveServer(zkConn zkhelper.Conn, addr string) error {
	zkPath := fmt.Sprintf("/zk/codis/db_%s/servers/group_%d/%s", self.ProductName, self.Id, addr)
	data, _, err := zkConn.Get(zkPath)
	if err != nil {
		return errors.Trace(err)
	}

	var s Server
	err = json.Unmarshal(data, &s)
	if err != nil {
		return errors.Trace(err)
	}
	log.Info(s)
	if s.Type == SERVER_TYPE_MASTER {
		return errors.Errorf("cannot remove master, use promote first")
	}

	err = zkConn.Delete(zkPath, -1)
	if err != nil {
		return errors.Trace(err)
	}

	// update server list
	for i := 0; i < len(self.Servers); i++ {
		if self.Servers[i].Addr == s.Addr {
			self.Servers = append(self.Servers[:i], self.Servers[i+1:]...)
			break
		}
	}

	// remove slave won't need proxy confirm
	err = NewAction(zkConn, self.ProductName, ACTION_TYPE_SERVER_GROUP_CHANGED, self, "", false)
	return errors.Trace(err)
}

func (d *Decoder) decodeResp(depth int) (*Resp, error) {
	b, err := d.ReadByte()
	if err != nil {
		return nil, errors.Trace(err)
	}
	switch t := RespType(b); t {
	case TypeString, TypeError, TypeInt:
		r := &Resp{Type: t}
		r.Value, err = d.decodeTextBytes()
		return r, err
	case TypeBulkBytes:
		r := &Resp{Type: t}
		r.Value, err = d.decodeBulkBytes()
		return r, err
	case TypeArray:
		r := &Resp{Type: t}
		r.Array, err = d.decodeArray(depth)
		return r, err
	default:
		if depth != 0 {
			return nil, errors.Errorf("bad resp type %s", t)
		}
		if err := d.UnreadByte(); err != nil {
			return nil, errors.Trace(err)
		}
		r := &Resp{Type: TypeArray}
		r.Array, err = d.decodeSingleLineBulkBytesArray()
		return r, err
	}
}

// experimental simple auto rebalance :)
func Rebalance() error {
	targetQuota, err := getQuotaMap(safeZkConn)
	if err != nil {
		return errors.Trace(err)
	}
	livingNodes, err := getLivingNodeInfos(safeZkConn)
	if err != nil {
		return errors.Trace(err)
	}
	log.Infof("start rebalance")
	for _, node := range livingNodes {
		for len(node.CurSlots) > targetQuota[node.GroupId] {
			for _, dest := range livingNodes {
				if dest.GroupId != node.GroupId && len(dest.CurSlots) < targetQuota[dest.GroupId] {
					slot := node.CurSlots[len(node.CurSlots)-1]
					// create a migration task
					info := &MigrateTaskInfo{
						Delay:      0,
						SlotId:     slot,
						NewGroupId: dest.GroupId,
						Status:     MIGRATE_TASK_PENDING,
						CreateAt:   strconv.FormatInt(time.Now().Unix(), 10),
					}
					globalMigrateManager.PostTask(info)

					node.CurSlots = node.CurSlots[0 : len(node.CurSlots)-1]
					dest.CurSlots = append(dest.CurSlots, slot)
				}
			}
		}
	}
	log.Infof("rebalance tasks submit finish")
	return nil
}

func (top *Topology) GetSlotByIndex(i int) (*models.Slot, *models.ServerGroup, error) {
	var slot *models.Slot
	var groupServer *models.ServerGroup
	var err error
	for {
		slot, err = models.GetSlot(top.zkConn, top.ProductName, i)
		if err == nil || top.IsFatalErr(err) {
			break
		} else {
			time.Sleep(ZK_RECONNECT_INTERVAL * time.Second)
		}
		if err != nil {
			log.ErrorErrorf(err, " GetSlot ")
		}
	}
	if err != nil {
		return nil, nil, errors.Trace(err)
	}

	for {
		groupServer, err = models.GetGroup(top.zkConn, top.ProductName, slot.GroupId)
		if err == nil || top.IsFatalErr(err) {
			break
		} else {
			time.Sleep(ZK_RECONNECT_INTERVAL * time.Second)
		}
		if err != nil {
			log.ErrorErrorf(err, " GetGroup ")
		}
	}
	if err != nil {
		return nil, nil, errors.Trace(err)
	}
	return slot, groupServer, nil
}

func ServerGroups(zkConn zkhelper.Conn, productName string) ([]*ServerGroup, error) {
	var ret []*ServerGroup
	root := fmt.Sprintf("/zk/codis/db_%s/servers", productName)
	groups, _, err := zkConn.Children(root)
	if err != nil {
		return nil, errors.Trace(err)
	}

	// Buggy :X
	//zkhelper.ChildrenRecursive(*zkConn, root)

	for _, group := range groups {
		// parse group_1 => 1
		groupId, err := strconv.Atoi(strings.Split(group, "_")[1])
		if err != nil {
			return nil, errors.Trace(err)
		}
		g, err := GetGroup(zkConn, productName, groupId)
		if err != nil {
			return nil, errors.Trace(err)
		}
		ret = append(ret, g)
	}
	return ret, nil
}

func SlotsInfo(addr, passwd string, fromSlot, toSlot int) (map[int]int, error) {
	c, err := DialTo(addr, passwd)
	if err != nil {
		return nil, err
	}
	defer c.Close()

	infos, err := redis.Values(c.Do("SLOTSINFO", fromSlot, toSlot-fromSlot+1))
	if err != nil {
		return nil, errors.Trace(err)
	}

	slots := make(map[int]int)
	if infos != nil {
		for i := 0; i < len(infos); i++ {
			info, err := redis.Values(infos[i], nil)
			if err != nil {
				return nil, errors.Trace(err)
			}
			var slotid, slotsize int
			if _, err := redis.Scan(info, &slotid, &slotsize); err != nil {
				return nil, errors.Trace(err)
			} else {
				slots[slotid] = slotsize
			}
		}
	}
	return slots, nil
}

func ForceRemoveDeadFence(zkConn zkhelper.Conn, productName string) error {
	proxies, err := ProxyList(zkConn, productName, func(p *ProxyInfo) bool {
		return p.State == PROXY_STATE_ONLINE
	})
	if err != nil {
		return errors.Trace(err)
	}
	fenceProxies, err := GetFenceProxyMap(zkConn, productName)
	if err != nil {
		return errors.Trace(err)
	}
	// remove online proxies's fence
	for _, proxy := range proxies {
		delete(fenceProxies, proxy.Addr)
	}

	// delete dead fence in zookeeper
	path := GetProxyFencePath(productName)
	for remainFence, _ := range fenceProxies {
		fencePath := filepath.Join(path, remainFence)
		log.Info("removing fence: ", fencePath)
		if err := zkhelper.DeleteRecursive(zkConn, fencePath, -1); err != nil {
			return errors.Trace(err)
		}
	}
	return nil
}

func (p *ProxyInfo) Ops() (int64, error) {
	resp, err := http.Get("http://" + p.DebugVarAddr + "/debug/vars")
	if err != nil {
		return -1, errors.Trace(err)
	}
	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return -1, errors.Trace(err)
	}

	m := make(map[string]interface{})
	err = json.Unmarshal(body, &m)
	if err != nil {
		return -1, errors.Trace(err)
	}

	if v, ok := m["router"]; ok {
		if vv, ok := v.(map[string]interface{})["ops"]; ok {
			return int64(vv.(float64)), nil
		}
	}

	return 0, nil
}

func (s *Slot) Update(zkConn zkhelper.Conn) error {
	// status validation
	switch s.State.Status {
	case SLOT_STATUS_MIGRATE, SLOT_STATUS_OFFLINE,
		SLOT_STATUS_ONLINE, SLOT_STATUS_PRE_MIGRATE:
		{
			// valid status, OK
		}
	default:
		{
			return errors.Trace(ErrUnknownSlotStatus)
		}
	}

	data, err := json.Marshal(s)
	if err != nil {
		return errors.Trace(err)
	}
	zkPath := GetSlotPath(s.ProductName, s.Id)
	_, err = zkhelper.CreateOrUpdate(zkConn, zkPath, string(data), 0, zkhelper.DefaultFileACLs(), true)
	if err != nil {
		return errors.Trace(err)
	}

	if s.State.Status == SLOT_STATUS_MIGRATE {
		err = NewAction(zkConn, s.ProductName, ACTION_TYPE_SLOT_MIGRATE, s, "", true)
	} else {
		err = NewAction(zkConn, s.ProductName, ACTION_TYPE_SLOT_CHANGED, s, "", true)
	}

	return errors.Trace(err)
}

func (e *Encoder) encodeTextString(s string) error {
	if _, err := e.WriteString(s); err != nil {
		return errors.Trace(err)
	}
	if _, err := e.WriteString("\r\n"); err != nil {
		return errors.Trace(err)
	}
	return nil
}

func (e *Encoder) encodeTextBytes(b []byte) error {
	if _, err := e.Write(b); err != nil {
		return errors.Trace(err)
	}
	if _, err := e.WriteString("\r\n"); err != nil {
		return errors.Trace(err)
	}
	return nil
}

func (d *Decoder) decodeTextBytes() ([]byte, error) {
	b, err := d.ReadBytes('\n')
	if err != nil {
		return nil, errors.Trace(err)
	}
	if n := len(b) - 2; n < 0 || b[n] != '\r' {
		return nil, errors.Trace(ErrBadRespCRLFEnd)
	} else {
		return b[:n], nil
	}
}

func GetServer(zkConn zkhelper.Conn, zkPath string) (*Server, error) {
	data, _, err := zkConn.Get(zkPath)
	if err != nil {
		return nil, errors.Trace(err)
	}
	srv := Server{}
	if err := json.Unmarshal(data, &srv); err != nil {
		return nil, errors.Trace(err)
	}
	return &srv, nil
}