add wait max slave acks config

config/config.go

@@ -34,6 +34,7 @@ type ReplicationConfig struct {
 	ExpiredLogDays   int    `toml:"expired_log_days"`
 	Sync             bool   `toml:"sync"`
 	WaitSyncTime     int    `toml:"wait_sync_time"`
+	WaitMaxSlaveAcks int    `toml:"wait_max_slave_acks"`
 	Compression      bool   `toml:"compression"`
 }
 
@@ -100,6 +101,7 @@ func NewConfigDefault() *Config {
 
 	cfg.Replication.WaitSyncTime = 1
 	cfg.Replication.Compression = true
+	cfg.Replication.WaitMaxSlaveAcks = 2
 
 	return cfg
 }

config/config.toml

@@ -60,5 +60,10 @@ sync = true
 # If sync is true, wait at last wait_sync_time seconds for slave syncing this log
 wait_sync_time = 1
 
+# If sync is true, wait at most min(wait_max_slave_acks, (n + 1) / 2) to promise syncing ok.
+# n is slave number
+# If 0, wait (n + 1) / 2 acks.
+wait_max_slave_acks = 2
+
 # Compress the log or not
 compression = true

config/config_test.go

@@ -5,7 +5,7 @@ import (
 )
 
 func TestConfig(t *testing.T) {
-	_, err := NewConfigWithFile("./config.toml")
+	_, err := NewConfigWithFile("./ledis.toml")
 	if err != nil {
 		t.Fatal(err)
 	}

etc/ledis.conf

@@ -1,7 +1,5 @@
 # LedisDB configuration
 
-# Config format is toml, https://github.com/toml-lang/toml
-
 # Server listen address
 addr = "127.0.0.1:6380"
 
@@ -15,6 +13,7 @@ data_dir = "/tmp/ledis_server"
 access_log = ""
 
 # Set slaveof to enable replication from master, empty, no replication
+# Any write operations except flushall and replication will be disabled in slave mode.
 slaveof = ""
 
 # Choose which backend storage to use, now support:
@@ -29,9 +28,12 @@ slaveof = ""
 #   
 db_name = "leveldb"
 
-# if not set, use data_dir/"db_name"_data
+# If not set, use data_dir/"db_name"_data
 db_path = ""
 
+# enable replication or not
+use_replication = true
+
 [leveldb]
 compression = false
 block_size = 32768
@@ -43,8 +45,25 @@ max_open_files = 1024
 map_size = 524288000
 nosync = true
 
-[wal]
+[replication]
-# if not set, use data_dir/wal
+# Path to store replication information(write ahead log, commit log, etc.)
+# if not set, use data_dir/rpl 
 path = ""
 
+# Expire write ahead logs after the given days
+expired_log_days = 7
 
+# If sync is true, the new log must be sent to some slaves, and then commit. 
+# It will reduce performance but have better high availability. 
+sync = true
+
+# If sync is true, wait at last wait_sync_time seconds for slave syncing this log
+wait_sync_time = 1
+
+# If sync is true, wait at most min(wait_max_slave_acks, (n + 1) / 2) to promise syncing ok.
+# n is slave number
+# If 0, wait (n + 1) / 2 acks.
+wait_max_slave_acks = 2
+
+# Compress the log or not
+compression = true

server/replication.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"github.com/siddontang/go/hack"
 	"github.com/siddontang/go/log"
+	"github.com/siddontang/go/num"
 	"github.com/siddontang/ledisdb/ledis"
 	"github.com/siddontang/ledisdb/rpl"
 	"net"
@@ -334,6 +335,11 @@ func (app *App) publishNewLog(l *rpl.Log) {
 		s.ack = ack
 	}
 
+	total := (len(ss) + 1) / 2
+	if app.cfg.Replication.WaitMaxSlaveAcks > 0 {
+		total = num.MinInt(total, app.cfg.Replication.WaitMaxSlaveAcks)
+	}
+
 	done := make(chan struct{}, 1)
 	go func(total int) {
 		n := 0
@@ -347,10 +353,11 @@ func (app *App) publishNewLog(l *rpl.Log) {
 			}
 		}
 		done <- struct{}{}
-	}((len(ss) + 1) / 2)
+	}(total)
 
 	select {
 	case <-done:
 	case <-time.After(time.Duration(app.cfg.Replication.WaitSyncTime) * time.Second):
+		log.Info("replication wait timeout")
 	}
 }