// background routine to initiate a connection sequence
// only connect if state == CELL_DISCONNECTED
// will change state to CELL_CONNECTING during the connection process
// will then change to CELL_CONNECTED (and braodcast the cond)
// or to CELL_BACKOFF (and schedule a new reconnection soon)
func (zcell *zkCell) connect() {
// change our state, we're working on connecting
zcell.mutex.Lock()
if zcell.state != CELL_DISCONNECTED {
// someone else is already connecting
zcell.mutex.Unlock()
return
}
zcell.state = CELL_CONNECTING
zcell.mutex.Unlock()
// now connect
zconn, session, err := zk.DialZkTimeout(zcell.zkAddr, *baseTimeout, *connectTimeout)
if err == nil {
zcell.zconn = zconn
go zcell.handleSessionEvents(session)
}
// and change our state
zcell.mutex.Lock()
if zcell.state != CELL_CONNECTING {
panic(fmt.Errorf("Unexpected state: %v", zcell.state))
}
if err == nil {
log.Infof("zk cell conn: cell %v connected", zcell.cellName)
zcell.state = CELL_CONNECTED
zcell.lastErr = nil
} else {
log.Infof("zk cell conn: cell %v connection failed: %v", zcell.cellName, err)
zcell.state = CELL_BACKOFF
zcell.lastErr = err
go func() {
// we're going to try to reconnect at some point
// FIXME(alainjobart) backoff algorithm?
<-time.NewTimer(time.Duration(*reconnectInterval) * time.Second).C
// switch back to DISCONNECTED, and trigger a connect
zcell.mutex.Lock()
zcell.state = CELL_DISCONNECTED
zcell.mutex.Unlock()
zcell.connect()
}()
}
// we broadcast on the condition to get everybody unstuck,
// whether we succeeded to connect or not
zcell.ready.Broadcast()
zcell.mutex.Unlock()
}
func main() {
defer logutil.Flush()
flag.Usage = func() {
fmt.Fprintf(os.Stderr, "Usage of %v:\n", os.Args[0])
flag.PrintDefaults()
fmt.Fprintf(os.Stderr, doc)
}
flag.Parse()
args := flag.Args()
if len(args) == 0 {
flag.Usage()
os.Exit(1)
}
if *zkAddrs != "" {
if *zkoccAddr != "" {
log.Fatalf("zk.addrs and zk.zkocc-addr are mutually exclusive")
}
var err error
zconn, _, err = zk.DialZkTimeout(*zkAddrs, 5*time.Second, 10*time.Second)
if err != nil {
log.Fatalf("zk connect failed: %v", err.Error())
}
}
if *zkoccAddr != "" {
var err error
zconn, err = zk.DialZkocc(*zkoccAddr, 5*time.Second)
if err != nil {
log.Fatalf("zkocc connect failed: %v", err.Error())
}
}
cmdName := args[0]
args = args[1:]
if cmd, ok := cmdMap[cmdName]; ok {
subFlags := flag.NewFlagSet(cmdName, flag.ExitOnError)
cmd(subFlags, args)
}
}