diff --git a/core/discov/facade.go b/core/discov/facade.go
index 2b7497a6..2a7838f2 100644
--- a/core/discov/facade.go
+++ b/core/discov/facade.go
@@ -2,7 +2,7 @@ package discov
 
 import (
 	"github.com/tal-tech/go-zero/core/discov/internal"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 )
 
 type (
@@ -26,7 +26,7 @@ func NewFacade(endpoints []string) Facade {
 
 func (f Facade) Client() internal.EtcdClient {
 	conn, err := f.registry.GetConn(f.endpoints)
-	lang.Must(err)
+	logx.Must(err)
 	return conn
 }
 
diff --git a/core/lang/lang.go b/core/lang/lang.go
index cf02ad6e..901c5604 100644
--- a/core/lang/lang.go
+++ b/core/lang/lang.go
@@ -1,16 +1,8 @@
 package lang
 
-import "log"
-
 var Placeholder PlaceholderType
 
 type (
 	GenericType     = interface{}
 	PlaceholderType = struct{}
 )
-
-func Must(err error) {
-	if err != nil {
-		log.Fatal(err)
-	}
-}
diff --git a/core/lang/lang_test.go b/core/lang/lang_test.go
deleted file mode 100644
index 6b3c6417..00000000
--- a/core/lang/lang_test.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package lang
-
-import "testing"
-
-func TestMust(t *testing.T) {
-	Must(nil)
-}
diff --git a/core/logx/logs.go b/core/logx/logs.go
index edb71040..b3ac081c 100644
--- a/core/logx/logs.go
+++ b/core/logx/logs.go
@@ -17,7 +17,6 @@ import (
 	"sync/atomic"
 
 	"github.com/tal-tech/go-zero/core/iox"
-	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/sysx"
 	"github.com/tal-tech/go-zero/core/timex"
 )
@@ -46,6 +45,7 @@ const (
 	levelInfo   = "info"
 	levelError  = "error"
 	levelSevere = "severe"
+	levelFatal  = "fatal"
 	levelSlow   = "slow"
 	levelStat   = "stat"
 
@@ -100,7 +100,7 @@ type (
 )
 
 func MustSetup(c LogConf) {
-	lang.Must(SetUp(c))
+	Must(SetUp(c))
 }
 
 // SetUp sets up the logx. If already set up, just return nil.
@@ -210,6 +210,14 @@ func Infof(format string, v ...interface{}) {
 	infoSync(fmt.Sprintf(format, v...))
 }
 
+func Must(err error) {
+	if err != nil {
+		msg := formatWithCaller(err.Error(), 3)
+		output(severeLog, levelFatal, msg)
+		os.Exit(1)
+	}
+}
+
 func SetLevel(level uint32) {
 	atomic.StoreUint32(&logLevel, level)
 }
diff --git a/core/logx/logs_test.go b/core/logx/logs_test.go
index d8cb7dbc..ede9d505 100644
--- a/core/logx/logs_test.go
+++ b/core/logx/logs_test.go
@@ -131,6 +131,10 @@ func TestSetLevelWithDuration(t *testing.T) {
 	assert.Equal(t, 0, writer.builder.Len())
 }
 
+func TestMustNil(t *testing.T) {
+	Must(nil)
+}
+
 func BenchmarkCopyByteSliceAppend(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		var buf []byte
diff --git a/core/stat/internal/cpu_linux.go b/core/stat/internal/cpu_linux.go
index fea314b7..460d3b99 100644
--- a/core/stat/internal/cpu_linux.go
+++ b/core/stat/internal/cpu_linux.go
@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/tal-tech/go-zero/core/iox"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 )
 
 const (
@@ -24,17 +24,17 @@ var (
 
 func init() {
 	cpus, err := perCpuUsage()
-	lang.Must(err)
+	logx.Must(err)
 	cores = uint64(len(cpus))
 
 	sets, err := cpuSets()
-	lang.Must(err)
+	logx.Must(err)
 	quota = float64(len(sets))
 	cq, err := cpuQuota()
 	if err == nil {
 		if cq != -1 {
 			period, err := cpuPeriod()
-			lang.Must(err)
+			logx.Must(err)
 
 			limit := float64(cq) / float64(period)
 			if limit < quota {
@@ -44,10 +44,10 @@ func init() {
 	}
 
 	preSystem, err = systemCpuUsage()
-	lang.Must(err)
+	logx.Must(err)
 
 	preTotal, err = totalCpuUsage()
-	lang.Must(err)
+	logx.Must(err)
 }
 
 func RefreshCpu() uint64 {
diff --git a/core/stores/internal/cleaner.go b/core/stores/internal/cleaner.go
index 3838207a..5d4b8656 100644
--- a/core/stores/internal/cleaner.go
+++ b/core/stores/internal/cleaner.go
@@ -5,7 +5,6 @@ import (
 	"time"
 
 	"github.com/tal-tech/go-zero/core/collection"
-	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/proc"
 	"github.com/tal-tech/go-zero/core/stat"
@@ -33,7 +32,7 @@ type delayTask struct {
 func init() {
 	var err error
 	timingWheel, err = collection.NewTimingWheel(time.Second, timingWheelSlots, clean)
-	lang.Must(err)
+	logx.Must(err)
 
 	proc.AddShutdownListener(func() {
 		timingWheel.Drain(clean)
diff --git a/core/sysx/host.go b/core/sysx/host.go
index dccddf9f..8cfb54a1 100644
--- a/core/sysx/host.go
+++ b/core/sysx/host.go
@@ -3,7 +3,7 @@ package sysx
 import (
 	"os"
 
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/stringx"
 )
 
 var hostname string
@@ -11,7 +11,9 @@ var hostname string
 func init() {
 	var err error
 	hostname, err = os.Hostname()
-	lang.Must(err)
+	if err != nil {
+		hostname = stringx.RandId()
+	}
 }
 
 func Hostname() string {
diff --git a/example/breaker/main.go b/example/breaker/main.go
index 8bfa30f5..23cae92e 100644
--- a/example/breaker/main.go
+++ b/example/breaker/main.go
@@ -10,6 +10,7 @@ import (
 
 	"github.com/tal-tech/go-zero/core/breaker"
 	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"gopkg.in/cheggaaa/pb.v1"
 )
 
@@ -99,7 +100,7 @@ func main() {
 
 	gb := breaker.NewBreaker()
 	fp, err := os.Create("result.csv")
-	lang.Must(err)
+	logx.Must(err)
 	defer fp.Close()
 	fmt.Fprintln(fp, "seconds,state,googleCalls,netflixCalls")
 
diff --git a/example/etcd/sub/sub.go b/example/etcd/sub/sub.go
index 559737ca..284f7f3a 100644
--- a/example/etcd/sub/sub.go
+++ b/example/etcd/sub/sub.go
@@ -5,12 +5,12 @@ import (
 	"time"
 
 	"github.com/tal-tech/go-zero/core/discov"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 )
 
 func main() {
 	sub, err := discov.NewSubscriber([]string{"etcd.discovery:2379"}, "028F2C35852D", discov.Exclusive())
-	lang.Must(err)
+	logx.Must(err)
 
 	ticker := time.NewTicker(time.Second * 3)
 	defer ticker.Stop()
diff --git a/example/http/breaker/client/client.go b/example/http/breaker/client/client.go
index a756c3e1..131f14f9 100644
--- a/example/http/breaker/client/client.go
+++ b/example/http/breaker/client/client.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/threading"
 	"gopkg.in/cheggaaa/pb.v1"
 )
@@ -119,14 +120,14 @@ func main() {
 	flag.Parse()
 
 	fp, err := os.Create("result.csv")
-	lang.Must(err)
+	logx.Must(err)
 	defer fp.Close()
 	fmt.Fprintln(fp, "seconds,goodOk,goodFail,goodReject,goodErrs,goodUnknowns,goodDropRatio,"+
 		"heavyOk,heavyFail,heavyReject,heavyErrs,heavyUnknowns,heavyDropRatio")
 
 	var gm, hm metric
 	dur, err := time.ParseDuration(*duration)
-	lang.Must(err)
+	logx.Must(err)
 	done := make(chan lang.PlaceholderType)
 	group := threading.NewRoutineGroup()
 	group.RunSafe(func() {
diff --git a/example/load/main.go b/example/load/main.go
index efefbfae..d4d6f8a0 100644
--- a/example/load/main.go
+++ b/example/load/main.go
@@ -13,7 +13,7 @@ import (
 
 	"github.com/tal-tech/go-zero/core/collection"
 	"github.com/tal-tech/go-zero/core/executors"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/core/syncx"
 	"gopkg.in/cheggaaa/pb.v1"
 )
@@ -47,7 +47,7 @@ func main() {
 	lessWriter = executors.NewLessExecutor(interval * total / 100)
 
 	fp, err := os.Create("result.csv")
-	lang.Must(err)
+	logx.Must(err)
 	defer fp.Close()
 	fmt.Fprintln(fp, "second,maxFlight,flying,agressiveAvgFlying,lazyAvgFlying,bothAvgFlying")
 
diff --git a/example/load/simulate/client/main.go b/example/load/simulate/client/main.go
index da98c97a..529d2f87 100644
--- a/example/load/simulate/client/main.go
+++ b/example/load/simulate/client/main.go
@@ -11,7 +11,7 @@ import (
 	"time"
 
 	"github.com/tal-tech/go-zero/core/fx"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 )
 
 var (
@@ -27,7 +27,7 @@ func main() {
 	flag.Parse()
 
 	fp, err := os.Create("result.csv")
-	lang.Must(err)
+	logx.Must(err)
 	defer fp.Close()
 	fmt.Fprintln(fp, "seconds,total,pass,fail,drop")
 
diff --git a/tools/goctl/api/dartgen/gen.go b/tools/goctl/api/dartgen/gen.go
index 68a48124..6ee7623a 100644
--- a/tools/goctl/api/dartgen/gen.go
+++ b/tools/goctl/api/dartgen/gen.go
@@ -4,7 +4,7 @@ import (
 	"errors"
 	"strings"
 
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/api/parser"
 	"github.com/urfave/cli"
 )
@@ -32,8 +32,8 @@ func DartCommand(c *cli.Context) error {
 		dir = dir + "/"
 	}
 	api.Info.Title = strings.Replace(apiFile, ".api", "", -1)
-	lang.Must(genData(dir+"data/", api))
-	lang.Must(genApi(dir+"api/", api))
-	lang.Must(genVars(dir + "vars/"))
+	logx.Must(genData(dir+"data/", api))
+	logx.Must(genApi(dir+"api/", api))
+	logx.Must(genVars(dir + "vars/"))
 	return nil
 }
diff --git a/tools/goctl/api/gogen/gen.go b/tools/goctl/api/gogen/gen.go
index 0b9c553a..80209f28 100644
--- a/tools/goctl/api/gogen/gen.go
+++ b/tools/goctl/api/gogen/gen.go
@@ -14,7 +14,7 @@ import (
 	"time"
 
 	"github.com/logrusorgru/aurora"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	apiformat "github.com/tal-tech/go-zero/tools/goctl/api/format"
 	"github.com/tal-tech/go-zero/tools/goctl/api/parser"
 	apiutil "github.com/tal-tech/go-zero/tools/goctl/api/util"
@@ -45,15 +45,15 @@ func GoCommand(c *cli.Context) error {
 		return err
 	}
 
-	lang.Must(util.MkdirIfNotExist(dir))
-	lang.Must(genEtc(dir, api))
-	lang.Must(genConfig(dir))
-	lang.Must(genMain(dir, api))
-	lang.Must(genServiceContext(dir, api))
-	lang.Must(genTypes(dir, api))
-	lang.Must(genHandlers(dir, api))
-	lang.Must(genRoutes(dir, api))
-	lang.Must(genLogic(dir, api))
+	logx.Must(util.MkdirIfNotExist(dir))
+	logx.Must(genEtc(dir, api))
+	logx.Must(genConfig(dir))
+	logx.Must(genMain(dir, api))
+	logx.Must(genServiceContext(dir, api))
+	logx.Must(genTypes(dir, api))
+	logx.Must(genHandlers(dir, api))
+	logx.Must(genRoutes(dir, api))
+	logx.Must(genLogic(dir, api))
 	// it does not work
 	format(dir)
 	createGoModFileIfNeed(dir)
diff --git a/tools/goctl/api/javagen/gen.go b/tools/goctl/api/javagen/gen.go
index 086e7dce..420265ef 100644
--- a/tools/goctl/api/javagen/gen.go
+++ b/tools/goctl/api/javagen/gen.go
@@ -6,7 +6,7 @@ import (
 	"strings"
 
 	"github.com/logrusorgru/aurora"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/api/parser"
 	"github.com/tal-tech/go-zero/tools/goctl/util"
 	"github.com/urfave/cli"
@@ -36,9 +36,9 @@ func JavaCommand(c *cli.Context) error {
 		packetName = packetName[:len(packetName)-4]
 	}
 
-	lang.Must(util.MkdirIfNotExist(dir))
-	lang.Must(genPacket(dir, packetName, api))
-	lang.Must(genComponents(dir, packetName, api))
+	logx.Must(util.MkdirIfNotExist(dir))
+	logx.Must(genPacket(dir, packetName, api))
+	logx.Must(genComponents(dir, packetName, api))
 
 	fmt.Println(aurora.Green("Done."))
 	return nil
diff --git a/tools/goctl/api/main.go b/tools/goctl/api/main.go
index 758d23ca..53cf4d0f 100644
--- a/tools/goctl/api/main.go
+++ b/tools/goctl/api/main.go
@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"os"
 
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/api/parser"
 )
 
@@ -14,8 +14,8 @@ func main() {
 	}
 
 	p, err := parser.NewParser(os.Args[1])
-	lang.Must(err)
+	logx.Must(err)
 	api, err := p.Parse()
-	lang.Must(err)
+	logx.Must(err)
 	fmt.Println(api)
 }
diff --git a/tools/goctl/api/tsgen/gen.go b/tools/goctl/api/tsgen/gen.go
index e21b085b..579378d9 100644
--- a/tools/goctl/api/tsgen/gen.go
+++ b/tools/goctl/api/tsgen/gen.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 
 	"github.com/logrusorgru/aurora"
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/api/parser"
 	"github.com/tal-tech/go-zero/tools/goctl/util"
 	"github.com/urfave/cli"
@@ -34,9 +34,9 @@ func TsCommand(c *cli.Context) error {
 		return err
 	}
 
-	lang.Must(util.MkdirIfNotExist(dir))
-	lang.Must(genHandler(dir, webApi, caller, api, unwrapApi))
-	lang.Must(genComponents(dir, api))
+	logx.Must(util.MkdirIfNotExist(dir))
+	logx.Must(genHandler(dir, webApi, caller, api, unwrapApi))
+	logx.Must(genComponents(dir, api))
 
 	fmt.Println(aurora.Green("Done."))
 	return nil
diff --git a/tools/goctl/api/util/util.go b/tools/goctl/api/util/util.go
index c4ec3256..afc77a55 100644
--- a/tools/goctl/api/util/util.go
+++ b/tools/goctl/api/util/util.go
@@ -8,13 +8,13 @@ import (
 	"path"
 	"strings"
 
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/api/spec"
 	"github.com/tal-tech/go-zero/tools/goctl/util"
 )
 
 func MaybeCreateFile(dir, subdir, file string) (fp *os.File, created bool, err error) {
-	lang.Must(util.MkdirIfNotExist(path.Join(dir, subdir)))
+	logx.Must(util.MkdirIfNotExist(path.Join(dir, subdir)))
 	fpath := path.Join(dir, subdir, file)
 	if util.FileExists(fpath) {
 		fmt.Printf("%s exists, ignored generation\n", fpath)
diff --git a/tools/goctl/update/update.go b/tools/goctl/update/update.go
index 480f8ab4..5b1e42b3 100644
--- a/tools/goctl/update/update.go
+++ b/tools/goctl/update/update.go
@@ -8,7 +8,6 @@ import (
 
 	"github.com/tal-tech/go-zero/core/conf"
 	"github.com/tal-tech/go-zero/core/hash"
-	"github.com/tal-tech/go-zero/core/lang"
 	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/tal-tech/go-zero/tools/goctl/update/config"
 	"github.com/tal-tech/go-zero/tools/goctl/util"
@@ -56,5 +55,5 @@ func main() {
 
 	fs := http.FileServer(http.Dir(c.FileDir))
 	http.Handle(c.FilePath, http.StripPrefix(c.FilePath, forChksumHandler(path.Join(c.FileDir, filename), fs)))
-	lang.Must(http.ListenAndServe(c.ListenOn, nil))
+	logx.Must(http.ListenAndServe(c.ListenOn, nil))
 }
diff --git a/tools/modelctl/model/modelgen/gen.go b/tools/modelctl/model/modelgen/gen.go
index 8601bc8d..c30f7cea 100644
--- a/tools/modelctl/model/modelgen/gen.go
+++ b/tools/modelctl/model/modelgen/gen.go
@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/tal-tech/go-zero/core/lang"
+	"github.com/tal-tech/go-zero/core/logx"
 	"github.com/urfave/cli"
 )
 
@@ -14,7 +14,7 @@ func FileModelCommand(c *cli.Context) error {
 	if len(configFile) == 0 {
 		return errors.New("missing config value")
 	}
-	lang.Must(genModelWithConfigFile(configFile))
+	logx.Must(genModelWithConfigFile(configFile))
 	return nil
 }
 
@@ -36,6 +36,6 @@ func CmdModelCommand(c *cli.Context) error {
 	user := addressArr[0]
 	host := addressArr[1]
 	address = fmt.Sprintf("%v@tcp(%v)/information_schema", user, host)
-	lang.Must(genModelWithDataSource(address, schema, force, redis, nil))
+	logx.Must(genModelWithDataSource(address, schema, force, redis, nil))
 	return nil
 }