func (a *HostAgent) processChildrenAndWait(conn *zk.Conn) bool {
processing := make(map[string]chan int)
ssDone := make(chan stateResult, 25)
hostPath := zzk.HostPath(a.hostId)
for {
children, _, zkEvent, err := conn.ChildrenW(hostPath)
if err != nil {
glog.V(0).Infoln("Unable to read children, retrying.")
time.Sleep(3 * time.Second)
return true
}
a.startMissingChildren(conn, children, processing, ssDone)
select {
case errc := <-a.closing:
glog.V(1).Info("Agent received interrupt")
err = waitForSsNodes(processing, ssDone)
errc <- err
return false
case ssResult := <-ssDone:
glog.V(1).Infof("Goroutine finished %s", ssResult.id)
delete(processing, ssResult.id)
case evt := <-zkEvent:
glog.V(1).Info("Agent event: ", evt)
}
}
}
func GetRouters(conn *zk.Conn) []string {
nodes, _, _, err := conn.ChildrenW(ZOOKEEPER_ROUTER_PATH)
if err != nil {
log.Error("get router from zk error:%v", err)
return []string{}
}
return nodes
}
func GetRoomConnector(conn *zk.Conn, roomid string) []string {
fpath := path.Join(ZOOKEEPER_ROOM_PATH, roomid)
nodes, _, _, err := conn.ChildrenW(fpath)
if err != nil {
log.Error("get roomid:%s from zk error:%v", roomid, err)
return []string{}
}
return nodes
}
func watchService(cpDao dao.ControlPlane, conn *zk.Conn, shutdown <-chan int, done chan<- string, serviceId string) {
defer func() {
glog.V(3).Info("Exiting function watchService ", serviceId)
done <- serviceId
}()
for {
var service dao.Service
_, zkEvent, err := zzk.LoadServiceW(conn, serviceId, &service)
if err != nil {
glog.Errorf("Unable to load service %s: %v", serviceId, err)
return
}
_, _, childEvent, err := conn.ChildrenW(zzk.ServicePath(serviceId))
glog.V(1).Info("Leader watching for changes to service ", service.Name)
// check current state
var serviceStates []*dao.ServiceState
err = zzk.GetServiceStates(conn, &serviceStates, serviceId)
if err != nil {
glog.Error("Unable to retrieve running service states: ", err)
return
}
// Is the service supposed to be running at all?
switch {
case service.DesiredState == dao.SVC_STOP:
shutdownServiceInstances(conn, serviceStates, len(serviceStates))
case service.DesiredState == dao.SVC_RUN:
updateServiceInstances(cpDao, conn, &service, serviceStates)
default:
glog.Warningf("Unexpected desired state %d for service %s", service.DesiredState, service.Name)
}
select {
case evt := <-zkEvent:
if evt.Type == zk.EventNodeDeleted {
glog.V(0).Info("Shutting down due to node delete ", serviceId)
shutdownServiceInstances(conn, serviceStates, len(serviceStates))
return
}
glog.V(1).Infof("Service %s received event: %v", service.Name, evt)
continue
case evt := <-childEvent:
glog.V(1).Infof("Service %s received child event: %v", service.Name, evt)
continue
case <-shutdown:
glog.V(1).Info("Leader stopping watch on ", service.Name)
return
}
}
}
func WatchChildren(conn *zk.Conn, zkPath string, onChange func(children []string)) {
CreateRecursive(conn, zkPath, "", 0, DefaultDirACLs())
for {
children, _, ch, err := conn.ChildrenW(zkPath)
if err != nil {
log.Errorf("watch children path error, path:%s, err:%v", zkPath, err)
continue
}
onChange(children)
select {
case <-ch:
}
}
}
func WatchConnChange(conn *zk.Conn) {
fpath := ZOOKEEPER_CONN_PATH
for {
log.Info("zk path:%s set a watch", fpath)
_, _, watch, err := conn.ChildrenW(fpath)
if err != nil {
log.Info("path:%s get error ,try later", fpath)
time.Sleep(10 * time.Second)
continue
}
event := <-watch
log.Info("zk path:%s receive a event %v", fpath, event)
UpdateConnectorList()
}
}
// GetNodesW get all child from zk path with a watch.
func GetNodesW(conn *zk.Conn, path string) ([]string, <-chan zk.Event, error) {
nodes, stat, watch, err := conn.ChildrenW(path)
if err != nil {
if err == zk.ErrNoNode {
return nil, nil, ErrNodeNotExist
}
glog.Errorf("zk.ChildrenW(\"%s\") error(%v)", path, err)
return nil, nil, err
}
if stat == nil {
return nil, nil, ErrNodeNotExist
}
if len(nodes) == 0 {
return nil, nil, ErrNoChild
}
return nodes, watch, nil
}
func mirror(conn *zk.Conn, path string) (chan []string, chan error) {
snapshots := make(chan []string)
errors := make(chan error)
go func() {
for {
snapshot, _, events, err := conn.ChildrenW(path)
if err != nil {
errors <- err
return
}
snapshots <- snapshot
evt := <-events
if evt.Err != nil {
errors <- evt.Err
return
}
}
}()
return snapshots, errors
}
func watchServices(cpDao dao.ControlPlane, conn *zk.Conn) {
processing := make(map[string]chan int)
sDone := make(chan string)
// When this function exits, ensure that any started goroutines get
// a signal to shutdown
defer func() {
glog.V(0).Info("Leader shutting down child goroutines")
for key, shutdown := range processing {
glog.V(1).Info("Sending shutdown signal for ", key)
shutdown <- 1
}
}()
for {
glog.V(1).Info("Leader watching for changes to ", zzk.SERVICE_PATH)
serviceIds, _, zkEvent, err := conn.ChildrenW(zzk.SERVICE_PATH)
if err != nil {
glog.Errorf("Leader unable to find any services: ", err)
return
}
for _, serviceId := range serviceIds {
if processing[serviceId] == nil {
glog.V(2).Info("Leader starting goroutine to watch ", serviceId)
serviceChannel := make(chan int)
processing[serviceId] = serviceChannel
go watchService(cpDao, conn, serviceChannel, sDone, serviceId)
}
}
select {
case evt := <-zkEvent:
glog.V(1).Info("Leader event: ", evt)
case serviceId := <-sDone:
glog.V(1).Info("Leading cleaning up for service ", serviceId)
delete(processing, serviceId)
}
}
}
func sinkChildEvents(conn *zk.Conn, path string, sink chan<- zk.Event) chan<- bool {
control := make(chan bool)
go func() {
_, _, selfCh, err := conn.ChildrenW(path)
if err != nil {
logger.Panic("failed to set listener on path")
}
for {
select {
case _ = <-control:
break
case ev := <-selfCh:
sink <- ev
_, _, selfCh, err = conn.ChildrenW(path)
if err != nil {
logger.Panic("failed to set listener on path")
}
}
}
}()
return control
}
func WatchRoomConnChange(conn *zk.Conn, roomid string, cancel <-chan int) {
fpath := path.Join(ZOOKEEPER_ROOM_PATH, roomid)
for {
log.Info("zk path:%s set a watch", fpath)
_, _, watch, err := conn.ChildrenW(fpath)
if err != nil {
log.Info("path:%s get error ,try later", fpath)
time.Sleep(10 * time.Second)
continue
}
select {
case event := <-watch:
log.Info("zk path:%s receive a event %v", fpath, event)
err = GetRoomConnectorFromZk(roomid)
if err != nil {
log.Error("get room:%s from zk error", roomid)
}
case <-cancel:
log.Info("cancel room:%s watch", roomid)
break
}
}
}