func main() {
flag.Parse()
// init config
if err := initConfig(); err != nil {
log.Error("init config error(%v)", err)
return
}
// init log
log.LoadConfiguration(conf.Log)
defer log.Close()
// init zk
zkConn = zkDial()
if zkConn == nil {
log.Error("zk dial error")
return
}
go watchPath()
c := make(chan os.Signal, 1)
signal.Notify(c, syscall.SIGHUP, syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGINT, syscall.SIGSTOP)
for {
s := <-c
log.Info("twemproxy agent get a signal %s", s.String())
switch s {
case syscall.SIGQUIT, syscall.SIGTERM, syscall.SIGSTOP, syscall.SIGINT:
return
case syscall.SIGHUP:
default:
return
}
}
}
// pingAndRetry ping the rpc connect and re connect when has an error.
func (c *Client) pingAndRetry(stop <-chan bool, client *rpc.Client, addr string) {
defer func() {
if err := client.Close(); err != nil {
log.Error("client.Close() error(%v)", err)
}
}()
var (
failed bool
status int
err error
tmp *rpc.Client
)
for {
select {
case <-stop:
log.Info("addr: \"%s\" pingAndRetry goroutine exit", addr)
return
default:
}
if !failed {
if err = client.Call(RPCPing, 0, &status); err != nil {
log.Error("client.Call(%s) error(%v)", RPCPing, err)
failed = true
continue
} else {
failed = false
time.Sleep(rpcClientPingSleep)
continue
}
}
if tmp, err = rpc.Dial("tcp", addr); err != nil {
log.Error("rpc.Dial(tcp, %s) error(%v)", addr, err)
time.Sleep(rpcClientRetrySleep)
continue
}
client = tmp
failed = false
log.Info("client reconnect %s ok", addr)
}
}
// zk get a zookeeper conn.
func zkDial() *zk.Conn {
conn, session, err := zk.Connect(conf.ZK, zkTimeout)
if err != nil {
log.Error("zk.Connect(\"%v\", %d) error(%v)", conf.ZK, zkTimeout, err)
return nil
}
go func() {
for {
event := <-session
log.Info("zookeeper get a event: %s", event.State.String())
}
}()
return conn
}
// Init init the gosnowflake client.
func Init(zservers []string, zpath string, ztimeout time.Duration) (err error) {
mutex.Lock()
defer mutex.Unlock()
if zkConn != nil {
return
}
zkPath = zpath
zkServers = zservers
zkTimeout = ztimeout
conn, session, err := zk.Connect(zkServers, zkTimeout)
if err != nil {
log.Error("zk.Connect(\"%v\", %d) error(%v)", zkServers, zkTimeout, err)
return
}
zkConn = conn
go func() {
for {
event := <-session
log.Info("zk connect get a event: %s", event.Type.String())
}
}()
return
}
// watchWorkerId watch the zk node change.
func (c *Client) watchWorkerId(workerId int64, workerIdStr string) {
workerIdPath := path.Join(zkPath, workerIdStr)
log.Debug("workerIdPath: %s", workerIdPath)
for {
rpcs, _, watch, err := zkConn.ChildrenW(workerIdPath)
if err != nil {
log.Error("zkConn.ChildrenW(%s) error(%v)", workerIdPath, err)
time.Sleep(zkNodeDelaySleep)
continue
}
if len(rpcs) == 0 {
log.Error("zkConn.ChildrenW(%s) no nodes", workerIdPath)
time.Sleep(zkNodeDelaySleep)
continue
}
// leader selection
sort.Strings(rpcs)
newLeader := rpcs[0]
if c.leader == newLeader {
log.Info("workerId: %s add a new standby gosnowflake node", workerIdStr)
} else {
log.Info("workerId: %s oldLeader: \"%s\", newLeader: \"%s\" not equals, continue leader selection", workerIdStr, c.leader, newLeader)
// get new leader info
workerNodePath := path.Join(zkPath, workerIdStr, newLeader)
bs, _, err := zkConn.Get(workerNodePath)
if err != nil {
log.Error("zkConn.Get(%s) error(%v)", workerNodePath, err)
time.Sleep(zkNodeDelaySleep)
continue
}
peer := &Peer{}
if err = json.Unmarshal(bs, peer); err != nil {
log.Error("json.Unmarshal(%s, peer) error(%v)", string(bs), err)
time.Sleep(zkNodeDelaySleep)
continue
}
// init rpc
tmpClients := make([]*rpc.Client, len(peer.RPC))
tmpStop := make(chan bool, 1)
for i, addr := range peer.RPC {
clt, err := rpc.Dial("tcp", addr)
if err != nil {
log.Error("rpc.Dial(tcp, \"%s\") error(%v)", addr, err)
continue
}
tmpClients[i] = clt
go c.pingAndRetry(tmpStop, clt, addr)
}
// old rpc clients
oldClients := c.clients
oldStop := c.stop
// atomic replace variable
c.leader = newLeader
c.clients = tmpClients
c.stop = tmpStop
// if exist, free resource
if oldClients != nil {
closeRpc(oldClients, oldStop)
}
}
// new zk event
event := <-watch
log.Error("zk node(\"%s\") changed %s", workerIdPath, event.Type.String())
}
}