implement master server client, remove unnecessary dummy variable

go/cmd/master/master.go

@@ -1,80 +1,32 @@
 package main
 
 import (
-	"fmt"
 	"net"
 	"net/http"
 	"net/rpc"
-	"os"
-	"path/filepath"
 	"strconv"
-	"strings"
 	"time"
 
 	"github.com/namsral/flag"
 
 	"github.com/PaddlePaddle/Paddle/go/master"
-	"github.com/PaddlePaddle/recordio"
 )
 
 func main() {
 	port := flag.Int("port", 8080, "port of the master server.")
-	dataset := flag.String("training_dataset", "", "dataset: comma separated path to RecordIO paths, supports golb patterns.")
+
 	faultTolerance := flag.Bool("fault_tolerance", false, "enable fault tolerance (requires etcd).")
 	taskTimeoutDur := flag.Duration("task_timout_dur", 20*time.Minute, "task timout duration.")
 	taskTimeoutMax := flag.Int("task_timeout_max", 3, "max timtout count for each task before it being declared failed task.")
 	chunkPerTask := flag.Int("chunk_per_task", 10, "chunk per task.")
 	flag.Parse()
 
-	if *dataset == "" {
-		panic("no dataset specified.")
-	}
-
 	if *faultTolerance {
 		panic("fault tolernance not implemented.")
-	}
-
-	var chunks []master.Chunk
-	var paths []string
-	ss := strings.Split(*dataset, ",")
-	fmt.Println(ss)
-	for _, s := range ss {
-		match, err := filepath.Glob(s)
-		if err != nil {
-			panic(err)
-		}
-		paths = append(paths, match...)
-	}
-
-	if len(paths) == 0 {
-		panic("no valid datset specified.")
-	}
-
-	idx := 0
-	for _, path := range paths {
-		f, err := os.Open(path)
-		if err != nil {
-			panic(err)
-		}
-
-		index, err := recordio.LoadIndex(f)
-		if err != nil {
-			panic(err)
-		}
-		f.Close()
 
-		count := index.NumChunks()
-		for i := 0; i < count; i++ {
-			chunk := master.Chunk{
-				Idx:   idx,
-				Path:  path,
-				Index: *index.ChunkIndex(i),
-			}
-			chunks = append(chunks, chunk)
-		}
 	}
 
-	s := master.NewService(chunks, *chunkPerTask, *taskTimeoutDur, *taskTimeoutMax)
+	s := master.NewService(*chunkPerTask, *taskTimeoutDur, *taskTimeoutMax)
 	err := rpc.Register(s)
 	if err != nil {
 		panic(err)

go/pserver/internal/connection/conn.go → go/connection/conn.go

@@ -2,6 +2,7 @@ package connection
 
 import (
 	"errors"
+	"log"
 	"net/rpc"
 	"sync"
 )
@@ -21,6 +22,18 @@ func New() *Conn {
 	return c
 }
 
+// Close closes the connection.
+func (c *Conn) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if c.client == nil {
+		return nil
+	}
+
+	return c.client.Close()
+}
+
 // Connect connects the connection to a address.
 func (c *Conn) Connect(addr string) error {
 	c.mu.Lock()
@@ -50,12 +63,20 @@ func (c *Conn) Connect(addr string) error {
 			c.waitConn = nil
 		}
 	} else {
+		err := client.Close()
+		if err != nil {
+			log.Println(err)
+		}
+
 		return errors.New("client already set from a concurrent goroutine")
 	}
 
 	return nil
 }
 
+// TODO(helin): refactor Call to be able to perform given retry
+// policy.
+
 // Call make a RPC call.
 //
 // Call will be blocked until the connection to remote RPC service

go/master/client.go

@@ -0,0 +1,82 @@
+package master
+
+import (
+	"log"
+	"time"
+
+	"github.com/PaddlePaddle/Paddle/go/connection"
+)
+
+// Addresser provide the address of the master server.
+type Addresser interface {
+	Address() string
+}
+
+// Client is the client of the master server.
+type Client struct {
+	conn *connection.Conn
+}
+
+// NewClient creates a new Client.
+func NewClient(addr Addresser) *Client {
+	c := &Client{}
+	c.conn = connection.New()
+	go c.monitorMaster(addr)
+	return c
+}
+
+func (c *Client) monitorMaster(addr Addresser) {
+	lastMaster := ""
+	monitor := func() {
+		// get the lastest address of the master server,
+		// connect to the new address once address changed.
+		curMaster := addr.Address()
+		if curMaster != lastMaster {
+			if curMaster == "" {
+				err := c.conn.Close()
+				if err != nil {
+					log.Println(err)
+				}
+			} else {
+				err := c.conn.Connect(curMaster)
+				if err != nil {
+					log.Println(err)
+
+					// connect to addr failed, set
+					// to last known addr in order
+					// to retry next time.
+					curMaster = lastMaster
+				}
+
+			}
+		}
+
+		lastMaster = curMaster
+	}
+
+	monitor()
+	ticker := time.NewTicker(10 * time.Second)
+	for _ = range ticker.C {
+		monitor()
+	}
+}
+
+// SetDataset set dataset for the master server to dispatch.
+//
+// SetDataset can be call multiple times from different nodes. But
+// only the first call will be honored.
+func (c *Client) SetDataset(globPaths []string) error {
+	return c.conn.Call("Service.SetDataset", globPaths, nil)
+}
+
+// GetTask gets a new task from the master server.
+func (c *Client) GetTask() (Task, error) {
+	var t Task
+	err := c.conn.Call("Service.GetTask", 0, &t)
+	return t, err
+}
+
+// TaskFinished tells the master server a task is finished.
+func (c *Client) TaskFinished(taskID int) error {
+	return c.conn.Call("Service.TaskFinished", taskID, nil)
+}

go/master/client_test.go

@@ -0,0 +1,120 @@
+package master_test
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"net/rpc"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+
+	"github.com/PaddlePaddle/Paddle/go/master"
+	"github.com/PaddlePaddle/recordio"
+)
+
+const (
+	totalTask    = 20
+	chunkPerTask = 10
+)
+
+var port int
+
+func init() {
+	log.SetLevel(log.ErrorLevel)
+
+	l, err := net.Listen("tcp", ":0")
+	if err != nil {
+		panic(err)
+	}
+
+	ss := strings.Split(l.Addr().String(), ":")
+	p, err := strconv.Atoi(ss[len(ss)-1])
+	if err != nil {
+		panic(err)
+	}
+	port = p
+
+	go func(l net.Listener) {
+		s := master.NewService(chunkPerTask, time.Second, 1)
+		server := rpc.NewServer()
+		err := server.Register(s)
+		if err != nil {
+			panic(err)
+		}
+
+		mux := http.NewServeMux()
+		mux.Handle(rpc.DefaultRPCPath, server)
+		err = http.Serve(l, mux)
+		if err != nil {
+			panic(err)
+		}
+	}(l)
+}
+
+type addresser string
+
+func (a addresser) Address() string {
+	return string(a)
+}
+
+func TestClientFull(t *testing.T) {
+	const p = "/tmp/master_client_test_0"
+	f, err := os.Create(p)
+	if err != nil {
+		panic(err)
+	}
+
+	for i := 0; i < totalTask*chunkPerTask; i++ {
+		w := recordio.NewWriter(f, -1, -1)
+		w.Write(nil)
+		// call Close to force RecordIO writing a chunk.
+		w.Close()
+	}
+	f.Close()
+
+	c := master.NewClient(addresser(fmt.Sprintf(":%d", port)))
+	c.SetDataset([]string{p})
+
+	checkOnePass := func(i int) {
+		var tasks []master.Task
+		for i := 0; i < totalTask; i++ {
+			task, err := c.GetTask()
+			if err != nil {
+				t.Fatal(i, err)
+			}
+			tasks = append(tasks, task)
+		}
+
+		_, err = c.GetTask()
+		if err == nil {
+			t.Fatal(i, "should get error.")
+		}
+
+		err = c.TaskFinished(tasks[0].ID)
+		if err != nil {
+			t.Fatal(err)
+		}
+		tasks = tasks[1:]
+		task, err := c.GetTask()
+		if err != nil {
+			t.Fatal(err)
+		}
+		tasks = append(tasks, task)
+
+		for _, task := range tasks {
+			err = c.TaskFinished(task.ID)
+			if err != nil {
+				t.Fatal(i, err)
+			}
+		}
+	}
+
+	for i := 0; i < 10; i++ {
+		checkOnePass(i)
+	}
+}