diff --git a/Dockerfile b/Dockerfile
index c4055e3..a3a7bfb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -32,8 +32,8 @@ VOLUME /data
 WORKDIR /data
 
 COPY --from=builder /build/rotom /data/rotom
-COPY config.json /etc/rotom/config.json
+COPY rotom.toml /etc/rotom/rotom.toml
 
 EXPOSE 6379
 
-CMD ["./rotom", "-config", "/etc/rotom/config.json"]
\ No newline at end of file
+CMD ["./rotom", "-conf", "/etc/rotom/rotom.toml"]
\ No newline at end of file
diff --git a/command.go b/command.go
index 922fd2d..d8661ae 100644
--- a/command.go
+++ b/command.go
@@ -70,6 +70,7 @@ var cmdTable = []*Command{
 	{"flushdb", flushdbCommand, 0, true},
 	{"load", loadCommand, 0, false},
 	{"save", saveCommand, 0, false},
+	{"config", configCommand, 2, false},
 }
 
 func equalFold(a, b string) bool {
@@ -609,6 +610,19 @@ func saveCommand(writer *resp.Writer, _ []redcon.RESP) {
 	writer.WriteString("OK")
 }
 
+func configCommand(writer *resp.Writer, args []redcon.RESP) {
+	key := args[0].String()
+	op := args[1].String()
+	switch strings.ToLower(op) {
+	case "get":
+		writer.WriteAny(configGet(key))
+	case "set":
+		writer.WriteString("OK")
+	default:
+		writer.WriteError(fmt.Sprintf("ERR unknown op type: %s", op))
+	}
+}
+
 func fetchMap(key []byte, setnx ...bool) (Map, error) {
 	return fetch(key, func() Map { return hash.New() }, setnx...)
 }
diff --git a/command_test.go b/command_test.go
index 77467a8..b268a4a 100644
--- a/command_test.go
+++ b/command_test.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"github.com/alicebob/miniredis/v2"
 	"math/rand/v2"
-	"os"
 	"sync"
 	"testing"
 	"time"
@@ -15,16 +14,8 @@ import (
 )
 
 func startup() {
-	config := &Config{
-		Port:           20082,
-		AppendOnly:     true,
-		AppendFileName: "test.aof",
-		Save:           true,
-		SaveFileName:   "dump.rdb",
-	}
-	_ = os.Remove(config.AppendFileName)
-	config4Server(config)
-	printBanner(config)
+	config4Server("rotom_test.toml")
+	printBanner()
 	RegisterAeLoop(&server)
 	// custom
 	server.aeLoop.AddTimeEvent(AeOnce, 300, func(_ *AeLoop, _ int, _ interface{}) {}, nil)
@@ -64,7 +55,7 @@ func TestCommand(t *testing.T) {
 		go startup()
 		time.Sleep(time.Second / 2)
 		rdb := redis.NewClient(&redis.Options{
-			Addr: ":20082",
+			Addr: ":7979",
 		})
 		sleepFn := func(dur time.Duration) {
 			time.Sleep(dur)
@@ -583,21 +574,3 @@ func testCommand(t *testing.T, testType string, rdb *redis.Client, sleepFn func(
 		ast.Nil(rdb.Close())
 	})
 }
-
-func TestConfig(t *testing.T) {
-	ast := assert.New(t)
-	cfg, _ := LoadConfig("config.json")
-	ast.Equal(cfg.Port, 6379)
-	_, err := LoadConfig("not-exist.json")
-	ast.NotNil(err)
-	_, err = LoadConfig("go.mod")
-	ast.NotNil(err)
-}
-
-func TestReadableSize(t *testing.T) {
-	ast := assert.New(t)
-	ast.Equal(readableSize(50), "50B")
-	ast.Equal(readableSize(50*KB), "50.0KB")
-	ast.Equal(readableSize(50*MB), "50.0MB")
-	ast.Equal(readableSize(50*GB), "50.0GB")
-}
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..2097e85
--- /dev/null
+++ b/config.go
@@ -0,0 +1,38 @@
+package main
+
+import (
+	"github.com/spf13/viper"
+)
+
+const (
+	defaultConfigFileName = "rotom.toml"
+)
+
+func initConfig(fileName string) error {
+	viper.SetConfigFile(fileName)
+	return viper.ReadInConfig()
+}
+
+func configGet(key string) any { return viper.Get(key) }
+
+func configGetString(key string) string { return viper.GetString(key) }
+
+func configGetInt(key string) int { return viper.GetInt(key) }
+
+func configGetBool(key string) bool { return viper.GetBool(key) }
+
+func configGetPort() int {
+	return configGetInt("tcp.port")
+}
+
+func configGetAppendOnly() bool {
+	return configGetBool("aof.appendonly")
+}
+
+func configGetAppendFileName() string {
+	return configGetString("aof.appendfilename")
+}
+
+func configGetDbFileName() string {
+	return configGetString("rdb.dbfilename")
+}
diff --git a/config.json b/config.json
deleted file mode 100644
index 6a830ea..0000000
--- a/config.json
+++ /dev/null
@@ -1,7 +0,0 @@
-{
-    "port": 6379,
-    "appendonly": false,
-    "appendfilename": "appendonly.aof",
-    "save": false,
-    "savefilename": "dump.rdb"
-}
diff --git a/const.go b/const.go
index 0ac5580..70fbbf0 100644
--- a/const.go
+++ b/const.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"github.com/dustin/go-humanize"
 	"github.com/redis/go-redis/v9"
 	"github.com/xgzlucario/rotom/internal/hash"
 	"github.com/xgzlucario/rotom/internal/iface"
@@ -28,9 +29,8 @@ const (
 )
 
 const (
-	KB = 1024
-	MB = 1024 * KB
-	GB = 1024 * MB
+	KB = humanize.Byte
+	MB = humanize.MiByte
 )
 
 var type2c = map[ObjectType]func() iface.Encoder{
diff --git a/go.mod b/go.mod
index 7b83a23..fa718ff 100644
--- a/go.mod
+++ b/go.mod
@@ -7,31 +7,47 @@ require (
 	github.com/chen3feng/stl4go v0.1.1
 	github.com/cockroachdb/swiss v0.0.0-20240612210725-f4de07ae6964
 	github.com/deckarep/golang-set/v2 v2.7.0
+	github.com/dustin/go-humanize v1.0.1
 	github.com/klauspost/rvarint v1.0.1
 	github.com/redis/go-redis/v9 v9.7.0
 	github.com/rs/zerolog v1.33.0
+	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.9.0
 	github.com/tidwall/mmap v0.3.0
 	github.com/tidwall/redcon v1.6.2
 	github.com/zyedidia/generic v1.2.1
-	golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f
+	golang.org/x/exp v0.0.0-20241210194714-1829a127f884
 	golang.org/x/sys v0.28.0
 )
 
 require (
 	github.com/alicebob/gopher-json v0.0.0-20230218143504-906a9b012302 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
 	github.com/edsrzf/mmap-go v1.2.0 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
+	github.com/fsnotify/fsnotify v1.8.0 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/magiconair/properties v1.8.9 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.3 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/rogpeppe/go-internal v1.13.1 // indirect
+	github.com/sagikazarmark/locafero v0.6.0 // indirect
+	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
+	github.com/sourcegraph/conc v0.3.0 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/spf13/cast v1.7.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/tidwall/btree v1.7.0 // indirect
 	github.com/tidwall/match v1.1.1 // indirect
 	github.com/yuin/gopher-lua v1.1.1 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+	gopkg.in/ini.v1 v1.67.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
diff --git a/go.sum b/go.sum
index 536d583..b047181 100644
--- a/go.sum
+++ b/go.sum
@@ -15,17 +15,27 @@ github.com/chen3feng/stl4go v0.1.1/go.mod h1:5ml3psLgETJjRJnMbPE+JiHLrCpt+Ajc2we
 github.com/cockroachdb/swiss v0.0.0-20240612210725-f4de07ae6964 h1:Ew0znI2JatzKy52N1iS5muUsHkf2UJuhocH7uFW7jjs=
 github.com/cockroachdb/swiss v0.0.0-20240612210725-f4de07ae6964/go.mod h1:yBRu/cnL4ks9bgy4vAASdjIW+/xMlFwuHKqtmh3GZQg=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
-github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
-github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
+github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/deckarep/golang-set/v2 v2.7.0 h1:gIloKvD7yH2oip4VLhsv3JyLLFnC0Y2mlusgcvJYW5k=
 github.com/deckarep/golang-set/v2 v2.7.0/go.mod h1:VAky9rY/yGXJOLEDv3OMci+7wtDpOF4IN+y82NBOac4=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
 github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/edsrzf/mmap-go v1.1.0/go.mod h1:19H/e8pUPLicwkyNgOykDXkJ9F0MHE+Z52B8EIth78Q=
 github.com/edsrzf/mmap-go v1.2.0 h1:hXLYlkbaPzt1SaQk+anYwKSRNhufIDCchSPkUD6dD84=
 github.com/edsrzf/mmap-go v1.2.0/go.mod h1:19H/e8pUPLicwkyNgOykDXkJ9F0MHE+Z52B8EIth78Q=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
+github.com/fsnotify/fsnotify v1.8.0 h1:dAwr6QBTBZIkG8roQaJjGof0pp0EeF+tNV7YBP3F/8M=
+github.com/fsnotify/fsnotify v1.8.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
+github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/klauspost/rvarint v1.0.1 h1:5G/DQaex33Z9TL38B0csG7a7DCa79wNUF3UO0GaDAEI=
 github.com/klauspost/rvarint v1.0.1/go.mod h1:N3y17WM1y6FeND/unrPnTyHXl4qMM8Ny7IU7pZYyAe8=
 github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
@@ -35,26 +45,46 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/magiconair/properties v1.8.9 h1:nWcCbLq1N2v/cpNsy5WvQ37Fb+YElfq20WJ/a8RkpQM=
+github.com/magiconair/properties v1.8.9/go.mod h1:Dhd985XPs7jluiymwWYZ0G4Z61jb3vdS329zhj2hYo0=
 github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
 github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
 github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
 github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/pkg/diff v0.0.0-20210226163009-20ebb0f2a09e/go.mod h1:pJLUxLENpZxwdsKMEsNbx1VGcRFpLqf3715MtcvvzbA=
+github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
+github.com/mitchellh/mapstructure v1.5.0/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
+github.com/pelletier/go-toml/v2 v2.2.3 h1:YmeHyLY8mFWbdkNWwpr+qIL2bEqT0o95WSdkNHvL12M=
+github.com/pelletier/go-toml/v2 v2.2.3/go.mod h1:MfCQTFTvCcUyyvvwm1+G6H/jORL20Xlb6rzQu9GuUkc=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
+github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/redis/go-redis/v9 v9.7.0 h1:HhLSs+B6O021gwzl+locl0zEDnyNkxMtf/Z3NNBMa9E=
 github.com/redis/go-redis/v9 v9.7.0/go.mod h1:f6zhXITC7JUJIlPEiBOTXxJgPLdZcA93GewI7inzyWw=
-github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
+github.com/sagikazarmark/locafero v0.6.0 h1:ON7AQg37yzcRPU69mt7gwhFEBwxI6P9T4Qu3N51bwOk=
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+github.com/sagikazarmark/slog-shim v0.1.0 h1:diDBnUNK9N/354PgrxMywXnAwEr1QZcOr6gto+ugjYE=
+github.com/sagikazarmark/slog-shim v0.1.0/go.mod h1:SrcSrq8aKtyuqEI1uvTDTK1arOWRIczQRv+GVI1AkeQ=
+github.com/sourcegraph/conc v0.3.0 h1:OQTbbt6P72L20UqAkXXuLOj79LfEanQ+YQFNpLA9ySo=
+github.com/sourcegraph/conc v0.3.0/go.mod h1:Sdozi7LEKbFPqYX2/J+iBAM6HpqSLTASQIKqDmF7Mt0=
+github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=
+github.com/spf13/afero v1.11.0/go.mod h1:GH9Y3pIexgf1MTIWtNGyogA5MwRIDXGUr+hbWNoBjkY=
+github.com/spf13/cast v1.7.0 h1:ntdiHjuueXFgm5nzDRdOS4yfT43P5Fnud6DH50rz/7w=
+github.com/spf13/cast v1.7.0/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+github.com/spf13/viper v1.19.0 h1:RWq5SEjt8o25SROyN3z2OrDB9l7RPd3lwTWU8EcEdcI=
+github.com/spf13/viper v1.19.0/go.mod h1:GQUN9bilAbhU/jgc1bKs99f/suXKeUMct8Adx5+Ntkg=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
+github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/tidwall/btree v1.1.0/go.mod h1:TzIRzen6yHbibdSfK6t8QimqbUnoxUSrZfeW7Uob0q4=
 github.com/tidwall/btree v1.7.0 h1:L1fkJH/AuEh5zBnnBbmTwQ5Lt+bRJ5A8EWecslvo9iI=
 github.com/tidwall/btree v1.7.0/go.mod h1:twD9XRA5jj9VUQGELzDO4HPQTNJsoWWfYEL+EUQ2cKY=
@@ -68,16 +98,22 @@ github.com/yuin/gopher-lua v1.1.1 h1:kYKnWBjvbNP4XLT3+bPEwAXJx262OhaHDWDVOPjL46M
 github.com/yuin/gopher-lua v1.1.1/go.mod h1:GBR0iDaNXjAgGg9zfCvksxSRnQx76gclCIb7kdAd1Pw=
 github.com/zyedidia/generic v1.2.1 h1:Zv5KS/N2m0XZZiuLS82qheRG4X1o5gsWreGb0hR7XDc=
 github.com/zyedidia/generic v1.2.1/go.mod h1:ly2RBz4mnz1yeuVbQA/VFwGjK3mnHGRj1JuoG336Bis=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f h1:XdNn9LlyWAhLVp6P/i8QYBW+hlyhrhei9uErw2B5GJo=
-golang.org/x/exp v0.0.0-20241108190413-2d47ceb2692f/go.mod h1:D5SMRVC3C2/4+F/DB1wZsLRnSNimn2Sp/NPsCrsv8ak=
+go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
+go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+golang.org/x/exp v0.0.0-20241210194714-1829a127f884 h1:Y/Mj/94zIQQGHVSv1tTtQBDaQaJe62U9bkDZKKyhPCU=
+golang.org/x/exp v0.0.0-20241210194714-1829a127f884/go.mod h1:qj5a5QZpwLU2NLQudwIN5koi3beDhSAlJwa67PuM98c=
 golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
 golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
+gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/internal/net/net.go b/internal/net/net.go
index f94d2d9..29293da 100644
--- a/internal/net/net.go
+++ b/internal/net/net.go
@@ -4,7 +4,15 @@ import (
 	"golang.org/x/sys/unix"
 )
 
-const BACKLOG int = 64
+/*
+BACKLOG is TCP listen() backlog.
+In high requests-per-second environments you need a high backlog in order
+to avoid slow clients connections issues. Note that the Linux kernel
+will silently truncate it to the value of /proc/sys/net/core/somaxconn so
+make sure to raise both the value of somaxconn and tcp_max_syn_backlog
+in order to get the desired effect.
+*/
+const BACKLOG int = 511
 
 func Accept(fd int) (int, error) {
 	nfd, _, err := unix.Accept(fd)
diff --git a/main.go b/main.go
index f7575b3..0b86fdc 100644
--- a/main.go
+++ b/main.go
@@ -26,16 +26,19 @@ func initLogger() zerolog.Logger {
 		Logger()
 }
 
-func config4Server(config *Config) {
-	if err := initServer(config); err != nil {
+func config4Server(fileName string) {
+	if err := initConfig(fileName); err != nil {
+		log.Fatal().Msgf("init config error: %v", err)
+	}
+	if err := initServer(); err != nil {
 		log.Fatal().Msgf("init server error: %v", err)
 	}
-	if err := InitDB(config); err != nil {
+	if err := InitDB(); err != nil {
 		log.Fatal().Msgf("init db error: %v", err)
 	}
 }
 
-func printBanner(config *Config) {
+func printBanner() {
 	log.Printf(`
 ________      _____                  
 ___  __ \_______  /_____________ ___   Rotom %d bit (%s/%s)
@@ -44,7 +47,7 @@ _  _, _// /_/ / /_ / /_/ /  / / / / /  Build: %s
 /_/ |_| \____/\__/ \____//_/ /_/ /_/
 	   `,
 		strconv.IntSize, runtime.GOARCH, runtime.GOOS,
-		config.Port, os.Getpid(),
+		configGetPort(), os.Getpid(),
 		buildTime)
 }
 
@@ -52,35 +55,26 @@ _  _, _// /_/ / /_ / /_/ /  / / / / /  Build: %s
 func RegisterAeLoop(server *Server) {
 	server.aeLoop.AddRead(server.fd, AcceptHandler, nil)
 	server.aeLoop.AddTimeEvent(AeNormal, 100, CronEvictExpired, nil)
-	if server.config.AppendOnly {
+	if configGetAppendOnly() {
 		server.aeLoop.AddTimeEvent(AeNormal, 1000, CronSyncAOF, nil)
 	}
-	if server.config.Save {
-		// TODO: rdb
-	}
 }
 
 func main() {
 	var path string
 	var debug bool
 
-	flag.StringVar(&path, "config", "config.json", "default config file path.")
+	flag.StringVar(&path, "conf", defaultConfigFileName, "config file path.")
 	flag.BoolVar(&debug, "debug", false, "run with debug mode.")
 	flag.Parse()
 
-	config, err := LoadConfig(path)
-	if err != nil {
-		log.Fatal().Msgf("load config error: %v", err)
-	}
-	printBanner(config)
+	config4Server(path)
+	printBanner()
 
 	if debug {
 		go http.ListenAndServe(":6060", nil)
 	}
 
-	log.Info().Str("config", path).Msg("read config file")
-	config4Server(config)
-
 	log.Info().Msg("rotom server is ready to accept.")
 
 	RegisterAeLoop(&server)
diff --git a/rdb.go b/rdb.go
index 74be18c..34a4c13 100644
--- a/rdb.go
+++ b/rdb.go
@@ -9,11 +9,10 @@ import (
 )
 
 type Rdb struct {
-	path string
 }
 
-func NewRdb(path string) *Rdb {
-	return &Rdb{path: path}
+func NewRdb() *Rdb {
+	return &Rdb{}
 }
 
 func (r *Rdb) SaveDB() (err error) {
@@ -54,12 +53,12 @@ func (r *Rdb) SaveDB() (err error) {
 	if err != nil {
 		return err
 	}
-	return os.Rename(fname, r.path)
+	return os.Rename(fname, configGetDbFileName())
 }
 
 func (r *Rdb) LoadDB() error {
 	// Read file data by mmap.
-	data, err := mmap.Open(r.path, false)
+	data, err := mmap.Open(configGetDbFileName(), false)
 	if len(data) == 0 {
 		return nil
 	}
diff --git a/rotom.go b/rotom.go
index 4fd7c60..3791da9 100644
--- a/rotom.go
+++ b/rotom.go
@@ -1,15 +1,12 @@
 package main
 
 import (
-	"encoding/json"
-	"fmt"
+	"github.com/dustin/go-humanize"
 	"github.com/tidwall/redcon"
 	"github.com/xgzlucario/rotom/internal/iface"
+	"github.com/xgzlucario/rotom/internal/list"
 	"github.com/xgzlucario/rotom/internal/net"
 	"github.com/xgzlucario/rotom/internal/resp"
-	"os"
-
-	"github.com/xgzlucario/rotom/internal/list"
 )
 
 const (
@@ -43,37 +40,28 @@ type Client struct {
 
 type Server struct {
 	fd      int
-	config  *Config
 	aeLoop  *AeLoop
 	clients map[int]*Client
 }
 
-type Config struct {
-	Port           int    `json:"port"`
-	AppendOnly     bool   `json:"appendonly"`
-	AppendFileName string `json:"appendfilename"`
-	Save           bool   `json:"save"`
-	SaveFileName   string `json:"savefilename"`
-}
-
 var (
 	db     DB
 	server Server
 )
 
 // InitDB initializes database and redo appendonly files if needed.
-func InitDB(config *Config) (err error) {
+func InitDB() (err error) {
 	db.dict = New()
 
-	if config.Save {
-		db.rdb = NewRdb(config.SaveFileName)
+	if configGetBool("save") {
+		db.rdb = NewRdb()
 		log.Debug().Msg("start loading rdb file...")
 		if err = db.rdb.LoadDB(); err != nil {
 			return err
 		}
 	}
-	if config.AppendOnly {
-		db.aof, err = NewAof(config.AppendFileName)
+	if configGetAppendOnly() {
+		db.aof, err = NewAof(configGetAppendFileName())
 		if err != nil {
 			return
 		}
@@ -93,18 +81,6 @@ func InitDB(config *Config) (err error) {
 	return nil
 }
 
-func LoadConfig(path string) (config *Config, err error) {
-	jsonStr, err := os.ReadFile(path)
-	if err != nil {
-		return
-	}
-	config = &Config{}
-	if err = json.Unmarshal(jsonStr, config); err != nil {
-		return nil, err
-	}
-	return
-}
-
 // AcceptHandler is the main file event of aeloop.
 func AcceptHandler(loop *AeLoop, fd int, _ interface{}) {
 	cfd, err := net.Accept(fd)
@@ -153,7 +129,8 @@ READ:
 	// queryBuf need grow up
 	if client.recvx == len(client.queryBuf) {
 		client.queryBuf = append(client.queryBuf, make([]byte, client.recvx)...)
-		log.Warn().Msgf("client %d queryBuf grow up to size %s", fd, readableSize(len(client.queryBuf)))
+		sz := uint64(len(client.queryBuf))
+		log.Warn().Msgf("client %d queryBuf grow up to size %s", fd, humanize.Bytes(sz))
 		goto READ
 	}
 
@@ -204,7 +181,7 @@ func ProcessQueryBuf(client *Client) {
 		} else {
 			cmd.process(client.replyWriter, respBuf)
 			// write aof file
-			if cmd.persist && server.config.AppendOnly {
+			if cmd.persist && configGetAppendOnly() {
 				_, _ = db.aof.Write(queryBuf[:n])
 			}
 		}
@@ -233,8 +210,7 @@ func SendReplyToClient(loop *AeLoop, fd int, extra interface{}) {
 	loop.ModRead(fd, ReadQueryFromClient, client)
 }
 
-func initServer(config *Config) (err error) {
-	server.config = config
+func initServer() (err error) {
 	server.clients = make(map[int]*Client)
 	// init aeLoop
 	server.aeLoop, err = AeLoopCreate()
@@ -242,31 +218,19 @@ func initServer(config *Config) (err error) {
 		return err
 	}
 	// init tcp server
-	server.fd, err = net.TcpServer(config.Port)
+	server.fd, err = net.TcpServer(configGetPort())
 	if err != nil {
 		return err
 	}
 	return nil
 }
 
-func CronSyncAOF(_ *AeLoop, _ int, _ interface{}) {
+func CronSyncAOF(ae *AeLoop, fd int, extra interface{}) {
 	if err := db.aof.Flush(); err != nil {
 		log.Error().Msgf("sync aof error: %v", err)
 	}
 }
 
-func CronEvictExpired(_ *AeLoop, _ int, _ interface{}) {
+func CronEvictExpired(ae *AeLoop, fd int, extra interface{}) {
 	db.dict.EvictExpired()
 }
-
-func readableSize[T int | uint64](sz T) string {
-	switch {
-	case sz >= GB:
-		return fmt.Sprintf("%.1fGB", float64(sz)/float64(GB))
-	case sz >= MB:
-		return fmt.Sprintf("%.1fMB", float64(sz)/float64(MB))
-	case sz >= KB:
-		return fmt.Sprintf("%.1fKB", float64(sz)/float64(KB))
-	}
-	return fmt.Sprintf("%dB", sz)
-}
diff --git a/rotom.toml b/rotom.toml
new file mode 100644
index 0000000..2fd9379
--- /dev/null
+++ b/rotom.toml
@@ -0,0 +1,11 @@
+[tcp]
+port = 6379
+
+[rdb]
+save = false
+dbfilename = "dump.rdb"
+
+[aof]
+appendonly = false
+appendfilename = "appendonly.aof"
+appendfsync = "everysec"
\ No newline at end of file
diff --git a/rotom_test.toml b/rotom_test.toml
new file mode 100644
index 0000000..53d4b13
--- /dev/null
+++ b/rotom_test.toml
@@ -0,0 +1,11 @@
+[tcp]
+port = 7979
+
+[rdb]
+save = true
+dbfilename = "dump.rdb"
+
+[aof]
+appendonly = true
+appendfilename = "appendonly.aof"
+appendfsync = "everysec"
\ No newline at end of file