optimize fullsync

cmd/ledis-dump/main.go

@@ -14,7 +14,7 @@ var port = flag.Int("port", 6380, "ledis server port")
 var sock = flag.String("sock", "", "ledis unix socket domain")
 var dumpFile = flag.String("o", "./ledis.dump", "dump file to save")
 
-var fullSyncCmd = []byte("*1\r\n$8\r\nfullsync\r\n") //fullsync
+var fullSyncCmd = []byte("*2\r\n$8\r\nfullsync\r\n$3\r\nnew\r\n") //fullsync
 
 func main() {
 	flag.Parse()

config/config.go

@@ -129,6 +129,7 @@ func NewConfigDefault() *Config {
 	cfg.Replication.Compression = true
 	cfg.Replication.WaitMaxSlaveAcks = 2
 	cfg.Replication.SyncLog = 0
+	cfg.Snapshot.MaxNum = 1
 
 	cfg.adjust()
 

config/config.toml

@@ -81,7 +81,7 @@ compression = true
 [snapshot]
 # Path to store snapshot dump file
 # if not set, use data_dir/snapshot
-# snapshot file name format is snap-2006-01-02T15:04:05.999999999.dmp
+# snapshot file name format is dmp-2006-01-02T15:04:05.999999999
 path = ""
 
 # Reserve newest max_num snapshot dump files

doc/commands.json

@@ -90,7 +90,7 @@
         "readonly": false
     },
     "FULLSYNC": {
-        "arguments": "-",
+        "arguments": "[NEW]",
         "group": "Replication",
         "readonly": false
 

doc/commands.md

@@ -123,7 +123,7 @@ Table of Contents
 	- [BXSCAN key [MATCH match] [COUNT count]](#bxscan-key-match-match-count-count)
 - [Replication](#replication)
 	- [SLAVEOF host port [RESTART] [READONLY]](#slaveof-host-port-restart-readonly)
-	- [FULLSYNC](#fullsync)
+	- [FULLSYNC [NEW]](#fullsync-new)
 	- [SYNC logid](#sync-logid)
 - [Server](#server)
 	- [PING](#ping)
@@ -2477,12 +2477,14 @@ If the server is already master, `SLAVEOF NO ONE READONLY` will force the server
 If a server is already a slave of a master, `SLAVEOF host port` will stop the replication against the old and start the synchronization against the new one, if RESTART is set, it will discard the old dataset, otherwise it will sync with LastLogID + 1. 
 
 
-### FULLSYNC
+### FULLSYNC [NEW]
 
 Inner command, starts a fullsync from the master set by SLAVEOF.
 
 FULLSYNC will first try to sync all data from the master, save in local disk, then discard old dataset and load new one.
 
+`FULLSYNC NEW` will generate a new snapshot and sync, otherwise it will use the latest existing snapshot if possible.
+
 **Return value**
 
 **Examples**

server/app.go

@@ -34,6 +34,8 @@ type App struct {
 	// handle slaves
 	slock  sync.Mutex
 	slaves map[*client]struct{}
+
+	snap *snapshotStore
 }
 
 func netType(s string) string {
@@ -88,6 +90,10 @@ func NewApp(cfg *config.Config) (*App, error) {
 		}
 	}
 
+	if app.snap, err = newSnapshotStore(cfg); err != nil {
+		return nil, err
+	}
+
 	if len(app.cfg.SlaveOf) > 0 {
 		//slave must readonly
 		app.cfg.Readonly = true
@@ -125,6 +131,8 @@ func (app *App) Close() {
 
 	app.m.Close()
 
+	app.snap.Close()
+
 	if app.access != nil {
 		app.access.Close()
 	}

server/cmd_replication.go

@@ -4,10 +4,9 @@ import (
 	"fmt"
 	"github.com/siddontang/go/hack"
 	"github.com/siddontang/ledisdb/ledis"
-	"io/ioutil"
-	"os"
 	"strconv"
 	"strings"
+	"time"
 )
 
 func slaveofCommand(c *client) error {
@@ -49,27 +48,46 @@ func slaveofCommand(c *client) error {
 }
 
 func fullsyncCommand(c *client) error {
-	//todo, multi fullsync may use same dump file
-	dumpFile, err := ioutil.TempFile(c.app.cfg.DataDir, "dump_")
+	args := c.args
+	needNew := false
+	if len(args) == 1 && strings.ToLower(hack.String(args[0])) == "new" {
+		needNew = true
+	}
+
+	var s *snapshot
+	var err error
+	var t time.Time
+
+	dumper := c.app.ldb
+
+	if needNew {
+		s, t, err = c.app.snap.Create(dumper)
+	} else {
+		if s, t, err = c.app.snap.OpenLatest(); err != nil {
+			return err
+		} else if s == nil {
+			s, t, err = c.app.snap.Create(dumper)
+		} else {
+			gap := time.Duration(c.app.cfg.Replication.ExpiredLogDays*24*3600) * time.Second / 2
+			minT := time.Now().Add(-gap)
+
+			//snapshot is too old
+			if t.Before(minT) {
+				s.Close()
+				s, t, err = c.app.snap.Create(dumper)
+			}
+		}
+	}
+
 	if err != nil {
 		return err
 	}
 
-	if err = c.app.ldb.Dump(dumpFile); err != nil {
-		return err
-	}
+	n := s.Size()
 
-	st, _ := dumpFile.Stat()
-	n := st.Size()
+	c.resp.writeBulkFrom(n, s)
 
-	dumpFile.Seek(0, os.SEEK_SET)
-
-	c.resp.writeBulkFrom(n, dumpFile)
-
-	name := dumpFile.Name()
-	dumpFile.Close()
-
-	os.Remove(name)
+	s.Close()
 
 	return nil
 }

server/snapshot.go

@@ -28,12 +28,13 @@ type snapshotStore struct {
 }
 
 func snapshotName(t time.Time) string {
-	return fmt.Sprintf("snap-%s.dmp", t.Format(snapshotTimeFormat))
+	return fmt.Sprintf("dmp-%s", t.Format(snapshotTimeFormat))
 }
 
 func parseSnapshotName(name string) (time.Time, error) {
 	var timeString string
-	if _, err := fmt.Sscanf(name, "snap-%s.dmp", &timeString); err != nil {
+	if _, err := fmt.Sscanf(name, "dmp-%s", &timeString); err != nil {
+		println(err.Error())
 		return time.Time{}, err
 	}
 	when, err := time.Parse(snapshotTimeFormat, timeString)
@@ -88,7 +89,7 @@ func (s *snapshotStore) checkSnapshots() error {
 		}
 
 		if _, err := parseSnapshotName(info.Name()); err != nil {
-			log.Error("invalid snapshot file name %s, err: %s, try remove", info.Name(), err.Error())
+			log.Error("invalid snapshot file name %s, err: %s", info.Name(), err.Error())
 			continue
 		}
 
@@ -161,8 +162,6 @@ type snapshot struct {
 	io.ReadCloser
 
 	f *os.File
-
-	temp bool
 }
 
 func (st *snapshot) Read(b []byte) (int, error) {
@@ -170,15 +169,7 @@ func (st *snapshot) Read(b []byte) (int, error) {
 }
 
 func (st *snapshot) Close() error {
-	if st.temp {
-		name := st.f.Name()
-		if err := st.f.Close(); err != nil {
-			return err
-		}
-		return os.Remove(name)
-	} else {
-		return st.f.Close()
-	}
+	return st.f.Close()
 }
 
 func (st *snapshot) Size() int64 {
@@ -186,20 +177,18 @@ func (st *snapshot) Size() int64 {
 	return s.Size()
 }
 
-func (s *snapshotStore) Create(d snapshotDumper, temp bool) (*snapshot, time.Time, error) {
+func (s *snapshotStore) Create(d snapshotDumper) (*snapshot, time.Time, error) {
 	s.Lock()
 	defer s.Unlock()
 
-	if !temp {
-		s.purge(true)
-	}
+	s.purge(true)
 
 	now := time.Now()
 	name := snapshotName(now)
 
 	tmpName := name + ".tmp"
 
-	if len(s.names) > 0 && !temp {
+	if len(s.names) > 0 {
 		lastTime, _ := parseSnapshotName(s.names[len(s.names)-1])
 		if !now.After(lastTime) {
 			return nil, time.Time{}, fmt.Errorf("create snapshot file time %s is behind %s ",
@@ -218,26 +207,17 @@ func (s *snapshotStore) Create(d snapshotDumper, temp bool) (*snapshot, time.Tim
 		return nil, time.Time{}, err
 	}
 
-	if temp {
-		if err := f.Sync(); err != nil {
-			f.Close()
-			return nil, time.Time{}, err
-		}
-
-		f.Seek(0, os.SEEK_SET)
-	} else {
-		f.Close()
-		if err := os.Rename(s.snapshotPath(tmpName), s.snapshotPath(name)); err != nil {
-			return nil, time.Time{}, err
-		}
-
-		if f, err = os.Open(s.snapshotPath(name)); err != nil {
-			return nil, time.Time{}, err
-		}
-		s.names = append(s.names, name)
+	f.Close()
+	if err := os.Rename(s.snapshotPath(tmpName), s.snapshotPath(name)); err != nil {
+		return nil, time.Time{}, err
 	}
 
-	return &snapshot{f: f, temp: temp}, now, nil
+	if f, err = os.Open(s.snapshotPath(name)); err != nil {
+		return nil, time.Time{}, err
+	}
+	s.names = append(s.names, name)
+
+	return &snapshot{f: f}, now, nil
 }
 
 func (s *snapshotStore) OpenLatest() (*snapshot, time.Time, error) {
@@ -256,5 +236,5 @@ func (s *snapshotStore) OpenLatest() (*snapshot, time.Time, error) {
 		return nil, time.Time{}, err
 	}
 
-	return &snapshot{f: f, temp: false}, t, err
+	return &snapshot{f: f}, t, err
 }

server/snapshot_test.go

@@ -30,7 +30,7 @@ func TestSnapshot(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if f, _, err := s.Create(d, false); err != nil {
+	if f, _, err := s.Create(d); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -43,7 +43,7 @@ func TestSnapshot(t *testing.T) {
 		}
 	}
 
-	if f, _, err := s.Create(d, false); err != nil {
+	if f, _, err := s.Create(d); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -55,7 +55,7 @@ func TestSnapshot(t *testing.T) {
 		}
 	}
 
-	if f, _, err := s.Create(d, false); err != nil {
+	if f, _, err := s.Create(d); err != nil {
 		t.Fatal(err)
 	} else {
 		defer f.Close()
@@ -73,29 +73,5 @@ func TestSnapshot(t *testing.T) {
 		t.Fatal("must 2 snapshot")
 	}
 
-	if f, _, err := s.Create(d, true); err != nil {
-		t.Fatal(err)
-	} else {
-		if b, _ := ioutil.ReadAll(f); string(b) != "hello world" {
-			t.Fatal("invalid read snapshot")
-		}
-
-		if len(s.names) != 2 {
-			t.Fatal("must 2 snapshot")
-		}
-
-		fs, _ = ioutil.ReadDir(cfg.Snapshot.Path)
-		if len(fs) != 3 {
-			t.Fatal("must 3 snapshot")
-		}
-
-		f.Close()
-	}
-
-	fs, _ = ioutil.ReadDir(cfg.Snapshot.Path)
-	if len(fs) != 2 {
-		t.Fatal("must 2 snapshot")
-	}
-
 	s.Close()
 }