// This is simple today - it returns the first listed service that matches the request
// Load balancing needs to be applied here somewhere.
func GetRandomClientByService(classname string) (*rpc.Client, os.Error) {
var newClient *rpc.Client
var err os.Error
serviceList := GetAllServiceProviders(classname)
if len(serviceList) > 0 {
chosen := rand.Int() % len(serviceList)
s := serviceList[chosen]
hostString := fmt.Sprintf("%s:%d", s.IPAddress, s.Port)
protocol := strings.ToLower(s.Protocol) // to be safe
switch protocol {
default:
newClient, err = rpc.DialHTTP("tcp", hostString)
case "json":
newClient, err = jsonrpc.Dial("tcp", hostString)
}
if err != nil {
LogWarn(fmt.Sprintf("Found %d nodes to provide service %s requested on %s, but failed to connect.",
len(serviceList), classname, hostString))
return nil, NewError(NO_CLIENT_PROVIDES_SERVICE, classname)
}
} else {
LogWarn(fmt.Sprintf("Found no node to provide service %s.", classname))
return nil, NewError(NO_CLIENT_PROVIDES_SERVICE, classname)
}
return newClient, nil
}
func GetAllClientsByService(classname string) (clientList []*rpc.Client) {
var newClient *rpc.Client
var err os.Error
serviceList := GetAllServiceProviders(classname)
for i, s := range serviceList {
hostString := fmt.Sprintf("%s:%d", s.IPAddress, s.Port)
protocol := strings.ToLower(s.Protocol) // to be safe
switch protocol {
default:
newClient, err = rpc.DialHTTP("tcp", hostString)
case "json":
newClient, err = jsonrpc.Dial("tcp", hostString)
}
if err != nil {
LogWarn(fmt.Sprintf("Found %d nodes to provide service %s requested on %s, but failed to connect to #%d.",
len(serviceList), classname, hostString, i))
//NewError(NO_CLIENT_PROVIDES_SERVICE, classname)
continue
}
clientList = append(clientList, newClient)
}
return
}
func main() {
r, err := jsonrpc.Dial("tcp", "localhost:6666")
if err != nil {
log.Exit("Error dialing host: ", err)
}
remote := &TestRPCSrv{r}
a := "foo"
var b string
err = remote.Call("testApp.PrintStuff", &a, &b)
if err != nil {
log.Exit("Error calling function: ", err)
}
log.Exit(b)
}