func (s *Server) Run(shutdown <-chan interface{}, conn client.Connection) error {
node := &Node{
Host: *s.host,
ExportPath: fmt.Sprintf("%s:%s", s.host.IPAddr, s.driver.ExportPath()),
ExportTime: strconv.FormatInt(time.Now().UnixNano(), 16),
}
// Create the storage leader and client nodes
if exists, _ := conn.Exists("/storage/leader"); !exists {
conn.CreateDir("/storage/leader")
}
storageClientsPath := "/storage/clients"
if exists, _ := conn.Exists(storageClientsPath); !exists {
conn.CreateDir(storageClientsPath)
}
leader := conn.NewLeader("/storage/leader", node)
leaderW, err := leader.TakeLead()
if err != zookeeper.ErrDeadlock && err != nil {
glog.Errorf("Could not take storage lead: %s", err)
return err
}
// monitor dfs; log warnings each cycle; restart dfs if needed
go s.monitor.MonitorDFSVolume(path.Join("/exports", s.driver.ExportPath()), s.host.IPAddr, node.ExportTime, shutdown, s.monitor.DFSVolumeMonitorPollUpdateFunc)
// loop until shutdown event
defer leader.ReleaseLead()
for {
clients, clientW, err := conn.ChildrenW(storageClientsPath)
if err != nil {
glog.Errorf("Could not set up watch for storage clients: %s", err)
return err
}
s.monitor.SetMonitorStorageClients(conn, storageClientsPath)
s.driver.SetClients(clients...)
if err := s.driver.Sync(); err != nil {
glog.Errorf("Error syncing driver: %s", err)
return err
}
select {
case e := <-clientW:
glog.Info("storage.server: receieved event: %s", e)
case <-leaderW:
err := fmt.Errorf("storage.server: lost lead")
return err
case <-shutdown:
return nil
}
}
}
func MonitorRealm(shutdown <-chan interface{}, conn client.Connection, path string) <-chan string {
realmC := make(chan string)
go func() {
defer close(realmC)
var realm string
leader := conn.NewLeader(path, &HostLeader{})
for {
// monitor path for changes
_, event, err := conn.ChildrenW(path)
if err != nil {
return
}
// Get the current leader and check for changes in its realm
var hl HostLeader
if err := leader.Current(&hl); err == zookeeper.ErrNoLeaderFound {
// pass
} else if err != nil {
return
} else if hl.Realm != realm {
realm = hl.Realm
select {
case realmC <- realm:
case <-shutdown:
return
}
}
select {
case <-event:
case <-shutdown:
return
}
}
}()
return realmC
}
// NewHostLeader initializes a new host leader
func NewHostLeader(conn client.Connection, hostID, realm, path string) client.Leader {
return conn.NewLeader(path, &HostLeader{HostID: hostID, Realm: realm})
}