add readonly support

cmd/ledis-cli/const.go

@@ -1,4 +1,4 @@
-//This file was generated by .tools/generate_commands.py on Wed Oct 08 2014 16:36:20 +0800 
+//This file was generated by .tools/generate_commands.py on Fri Oct 10 2014 09:08:54 +0800 
 package main
 
 var helpCommands = [][]string{
@@ -87,7 +87,7 @@ var helpCommands = [][]string{
 	{"SINTER", "key [key ...]", "Set"},
 	{"SINTERSTORE", "destination key [key ...]", "Set"},
 	{"SISMEMBER", "key member", "Set"},
-	{"SLAVEOF", "host port [restart]", "Replication"},
+	{"SLAVEOF", "host port [RESTART] [READONLY]", "Replication"},
 	{"SMCLEAR", "key [key ...]", "Set"},
 	{"SMEMBERS", "key", "Set"},
 	{"SPERSIST", "key", "Set"},

cmd/ledis-server/main.go

@@ -18,6 +18,8 @@ var configFile = flag.String("config", "", "ledisdb config file")
 var dbName = flag.String("db_name", "", "select a db to use, it will overwrite the config's db name")
 var usePprof = flag.Bool("pprof", false, "enable pprof")
 var pprofPort = flag.Int("pprof_port", 6060, "pprof http port")
+var slaveof = flag.String("slaveof", "", "make the server a slave of another instance")
+var readonly = flag.Bool("readonly", false, "set readonly mode, salve server is always readonly")
 
 func main() {
 	runtime.GOMAXPROCS(runtime.NumCPU())
@@ -43,6 +45,13 @@ func main() {
 		cfg.DBName = *dbName
 	}
 
+	if len(*slaveof) > 0 {
+		cfg.SlaveOf = *slaveof
+		cfg.Readonly = true
+	} else {
+		cfg.Readonly = *readonly
+	}
+
 	var app *server.App
 	app, err = server.NewApp(cfg)
 	if err != nil {

config/config.go

@@ -54,6 +54,8 @@ type Config struct {
 
 	SlaveOf string `toml:"slaveof"`
 
+	Readonly bool `toml:readonly`
+
 	DataDir string `toml:"data_dir"`
 
 	DBName string `toml:"db_name"`
@@ -106,6 +108,7 @@ func NewConfigDefault() *Config {
 	cfg.DBName = DefaultDBName
 
 	cfg.SlaveOf = ""
+	cfg.Readonly = false
 
 	// disable access log
 	cfg.AccessLog = ""

config/config.toml

@@ -16,6 +16,10 @@ access_log = ""
 # Any write operations except flushall and replication will be disabled in slave mode.
 slaveof = ""
 
+# Readonly mode, slave server is always readonly even readonly = false  
+# for readonly mode, only replication and flushall can write
+readonly = false
+
 # Choose which backend storage to use, now support:
 #
 #   leveldb

doc/commands.json

@@ -301,7 +301,7 @@
         "readonly": false
     },
     "SLAVEOF": {
-        "arguments": "host port [restart]",
+        "arguments": "host port [RESTART] [READONLY]",
         "group": "Replication",
         "readonly": false
     },

doc/commands.md

@@ -122,7 +122,7 @@ Table of Contents
 	- [BPERSIST key](#bpersist-key)
 	- [BXSCAN key [MATCH match] [COUNT count]](#bxscan-key-match-match-count-count)
 - [Replication](#replication)
-	- [SLAVEOF host port [restart]](#slaveof-host-port-restart)
+	- [SLAVEOF host port [RESTART] [READONLY]](#slaveof-host-port-restart-readonly)
 	- [FULLSYNC](#fullsync)
 	- [SYNC logid](#sync-logid)
 - [Server](#server)
@@ -2466,13 +2466,15 @@ See [XSCAN](#xscan-key-match-match-count-count) for more information.
 
 ## Replication
 
-### SLAVEOF host port [restart]
+### SLAVEOF host port [RESTART] [READONLY]
 
-Changes the replication settings of a slave on the fly. If the server is already acting as slave, SLAVEOF NO ONE will turn off the replication.
+Changes the replication settings of a slave on the fly. If the server is already acting as slave, `SLAVEOF NO ONE` will turn off the replication and turn the server into master. `SLAVEOF NO ONE READONLY` will turn the server into master with readonly mode. 
 
-SLAVEOF host port will make the server a slave of another server listening at the specified host and port.
+If the server is already master, `SLAVEOF NO ONE READONLY` will force the server to readonly mode, and `SLAVEOF NO ONE` will disable readonly.
 
-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. 
+`SLAVEOF host port` will make the server a slave of another server listening at the specified host and port.
+
+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

etc/ledis.conf

@@ -16,6 +16,10 @@ access_log = ""
 # Any write operations except flushall and replication will be disabled in slave mode.
 slaveof = ""
 
+# Readonly mode, slave server is always readonly even readonly = false  
+# for readonly mode, only replication and flushall can write
+readonly = false
+
 # Choose which backend storage to use, now support:
 #
 #   leveldb

ledis/const.go

@@ -46,11 +46,6 @@ var (
 	}
 )
 
-const (
-	RDWRMode  = 0
-	ROnlyMode = 1
-)
-
 const (
 	defaultScanCount int = 10
 )

ledis/ledis.go

@@ -33,17 +33,10 @@ type Ledis struct {
 	wLock      sync.RWMutex //allow one write at same time
 	commitLock sync.Mutex   //allow one write commit at same time
 
-	// for readonly mode, only replication and flushall can write
-	readOnly bool
-
 	lock io.Closer
 }
 
 func Open(cfg *config.Config) (*Ledis, error) {
-	return Open2(cfg, RDWRMode)
-}
-
-func Open2(cfg *config.Config, flags int) (*Ledis, error) {
 	if len(cfg.DataDir) == 0 {
 		cfg.DataDir = config.DefaultDataDir
 	}
@@ -53,13 +46,12 @@ func Open2(cfg *config.Config, flags int) (*Ledis, error) {
 	var err error
 
 	l := new(Ledis)
+	l.cfg = cfg
 
 	if l.lock, err = filelock.Lock(path.Join(cfg.DataDir, "LOCK")); err != nil {
 		return nil, err
 	}
 
-	l.readOnly = (flags&ROnlyMode > 0)
-
 	l.quit = make(chan struct{})
 
 	if l.ldb, err = store.Open(cfg); err != nil {
@@ -163,7 +155,7 @@ func (l *Ledis) flushAll() error {
 }
 
 func (l *Ledis) IsReadOnly() bool {
-	if l.readOnly {
+	if l.cfg.Readonly {
 		return true
 	} else if l.r != nil {
 		if b, _ := l.r.CommitIDBehind(); b {
@@ -173,10 +165,6 @@ func (l *Ledis) IsReadOnly() bool {
 	return false
 }
 
-func (l *Ledis) SetReadOnly(b bool) {
-	l.readOnly = b
-}
-
 func (l *Ledis) onDataExpired() {
 	defer l.wg.Done()
 

ledis/replication.go

@@ -110,7 +110,7 @@ func (l *Ledis) WaitReplication() error {
 func (l *Ledis) StoreLogsFromReader(rb io.Reader) error {
 	if !l.ReplicationUsed() {
 		return ErrRplNotSupport
-	} else if !l.readOnly {
+	} else if !l.cfg.Readonly {
 		return ErrRplInRDWR
 	}
 

ledis/replication_test.go

@@ -46,10 +46,11 @@ func TestReplication(t *testing.T) {
 	cfgS := new(config.Config)
 	cfgS.DataDir = "/tmp/test_repl/slave"
 	cfgS.UseReplication = true
+	cfgS.Readonly = true
 
 	os.RemoveAll(cfgS.DataDir)
 
-	slave, err = Open2(cfgS, ROnlyMode)
+	slave, err = Open(cfgS)
 	if err != nil {
 		t.Fatal(err)
 	}

server/app.go

@@ -88,13 +88,12 @@ func NewApp(cfg *config.Config) (*App, error) {
 		}
 	}
 
-	flag := ledis.RDWRMode
 	if len(app.cfg.SlaveOf) > 0 {
 		//slave must readonly
-		flag = ledis.ROnlyMode
+		app.cfg.Readonly = true
 	}
 
-	if app.ldb, err = ledis.Open2(cfg, flag); err != nil {
+	if app.ldb, err = ledis.Open(cfg); err != nil {
 		return nil, err
 	}
 
@@ -135,7 +134,7 @@ func (app *App) Close() {
 
 func (app *App) Run() {
 	if len(app.cfg.SlaveOf) > 0 {
-		app.slaveof(app.cfg.SlaveOf, false)
+		app.slaveof(app.cfg.SlaveOf, false, app.cfg.Readonly)
 	}
 
 	go app.httpServe()

server/cmd_replication.go

@@ -13,18 +13,19 @@ import (
 func slaveofCommand(c *client) error {
 	args := c.args
 
-	if len(args) != 2 || len(args) != 3 {
+	if len(args) != 2 && len(args) != 3 {
 		return ErrCmdParams
 	}
 
 	masterAddr := ""
 	restart := false
+	readonly := false
 
 	if strings.ToLower(hack.String(args[0])) == "no" &&
 		strings.ToLower(hack.String(args[1])) == "one" {
 		//stop replication, use master = ""
-		if len(args) != 2 {
-			return ErrCmdParams
+		if len(args) == 3 && strings.ToLower(hack.String(args[2])) == "readonly" {
+			readonly = true
 		}
 	} else {
 		if _, err := strconv.ParseInt(hack.String(args[1]), 10, 16); err != nil {
@@ -38,7 +39,7 @@ func slaveofCommand(c *client) error {
 		}
 	}
 
-	if err := c.app.slaveof(masterAddr, restart); err != nil {
+	if err := c.app.slaveof(masterAddr, restart, readonly); err != nil {
 		return err
 	}
 

server/cmd_replication_test.go

@@ -96,7 +96,7 @@ func TestReplication(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	slave.slaveof("", false)
+	slave.slaveof("", false, false)
 
 	db.Set([]byte("a2"), value)
 	db.Set([]byte("b2"), value)
@@ -112,7 +112,7 @@ func TestReplication(t *testing.T) {
 		t.Fatal("must error")
 	}
 
-	slave.slaveof(masterCfg.Addr, false)
+	slave.slaveof(masterCfg.Addr, false, false)
 
 	time.Sleep(1 * time.Second)
 

server/info.go

@@ -115,7 +115,8 @@ func (i *info) dumpServer(buf *bytes.Buffer) {
 	i.dumpPairs(buf, infoPair{"os", i.Server.OS},
 		infoPair{"process_id", i.Server.ProceessId},
 		infoPair{"addr", i.app.cfg.Addr},
-		infoPair{"http_addr", i.app.cfg.HttpAddr})
+		infoPair{"http_addr", i.app.cfg.HttpAddr},
+		infoPair{"readonly", i.app.cfg.Readonly})
 }
 
 func (i *info) dumpClients(buf *bytes.Buffer) {
@@ -155,10 +156,10 @@ func (i *info) dumpReplication(buf *bytes.Buffer) {
 		slaves = append(slaves, s.remoteAddr)
 	}
 
-	p = append(p, infoPair{"readonly", i.app.ldb.IsReadOnly()})
+	p = append(p, infoPair{"slaveof", i.app.cfg.SlaveOf})
 
 	if len(slaves) > 0 {
-		p = append(p, infoPair{"slave", strings.Join(slaves, ",")})
+		p = append(p, infoPair{"slaves", strings.Join(slaves, ",")})
 	}
 
 	if s, _ := i.app.ldb.ReplicationStat(); s != nil {

server/replication.go

@@ -93,7 +93,7 @@ func (m *master) startReplication(masterAddr string, restart bool) error {
 
 	m.quit = make(chan struct{}, 1)
 
-	m.app.ldb.SetReadOnly(true)
+	m.app.cfg.Readonly = true
 
 	m.wg.Add(1)
 	go m.runReplication(restart)
@@ -238,10 +238,16 @@ func (m *master) sync() error {
 
 }
 
-func (app *App) slaveof(masterAddr string, restart bool) error {
+func (app *App) slaveof(masterAddr string, restart bool, readonly bool) error {
 	app.m.Lock()
 	defer app.m.Unlock()
 
+	//in master mode and no slaveof, only set readonly
+	if len(app.cfg.SlaveOf) == 0 && len(masterAddr) == 0 {
+		app.cfg.Readonly = readonly
+		return nil
+	}
+
 	if !app.ldb.ReplicationUsed() {
 		return fmt.Errorf("slaveof must enable replication")
 	}
@@ -253,7 +259,7 @@ func (app *App) slaveof(masterAddr string, restart bool) error {
 			return err
 		}
 
-		app.ldb.SetReadOnly(false)
+		app.cfg.Readonly = readonly
 	} else {
 		return app.m.startReplication(masterAddr, restart)
 	}