diff --git a/cmd/diagnosis/main.go b/cmd/diagnosis/main.go
index 616ae15..4d0dad2 100644
--- a/cmd/diagnosis/main.go
+++ b/cmd/diagnosis/main.go
@@ -9,6 +9,8 @@ import (
 )
 
 func main() {
+	//log.SetFlags(log.Ldate | log.Ltime | log.Lmicroseconds | log.Llongfile)
+	log.SetFlags(log.Ldate | log.Ltime | log.Lmicroseconds | log.Lshortfile)
 
 	mux := http.NewServeMux()
 
diff --git a/diagnosis/fetching.go b/diagnosis/fetching.go
index d76830f..b2763f1 100644
--- a/diagnosis/fetching.go
+++ b/diagnosis/fetching.go
@@ -1,7 +1,7 @@
 package diagnosis
 
 import (
-	"fmt"
+	"log"
 	"net"
 	"os"
 
@@ -15,37 +15,37 @@ func New() *Info {
 	//hostname
 	hostname, err := os.Hostname()
 	if err != nil {
-		fmt.Printf("get hostname failed, err %v\n", err)
+		log.Printf("get hostname failed, err %v\n", err)
 	} else {
-		fmt.Printf("Hostname: %s\n", hostname)
+		log.Printf("Hostname: %s\n", hostname)
 		info.Hostname = hostname
 	}
 
 	//ip addresses
 	addrs, err := net.InterfaceAddrs()
 	if err != nil {
-		fmt.Printf("lookup network interface addrs failed, err %v\n", err)
+		log.Printf("lookup network interface addrs failed, err %v\n", err)
 	} else {
 		for _, addr := range addrs {
 			ip, _, err := net.ParseCIDR(addr.String())
 			if err != nil {
-				fmt.Printf("ParseCIDR addrs failed, err %v\n", err)
+				log.Printf("ParseCIDR addrs failed, err %v\n", err)
 				continue
 			}
 
 			if ip.IsLoopback() {
-				fmt.Printf("ignore Loopback ip address-->%s\n", addr.String())
+				log.Printf("ignore Loopback ip address-->%s\n", addr.String())
 				continue
 			}
 
-			fmt.Printf("%s ip address-->%s\n", addr.Network(), addr.String())
+			log.Printf("%s ip address-->%s\n", addr.Network(), addr.String())
 			info.IPAddresses = append(info.IPAddresses, addr.String())
 		}
 	}
 
 	//from goInfo
 	gi := goInfo.GetInfo()
-	gi.VarDump()
+	log.Println(gi)
 	info.CPUs = gi.CPUs
 
 	return &info
diff --git a/diagnosis/info.go b/diagnosis/info.go
index f0b2a16..81c50ec 100644
--- a/diagnosis/info.go
+++ b/diagnosis/info.go
@@ -2,7 +2,7 @@ package diagnosis
 
 import (
 	"encoding/json"
-	"fmt"
+	"log"
 )
 
 // Info includes information for diagnosis.
@@ -19,7 +19,7 @@ type Info struct {
 func (info Info) String() string {
 	jsonstr, err := json.Marshal(info)
 	if err != nil {
-		fmt.Printf("to json failed, err %v\n", err)
+		log.Fatalf("to json failed, err %v\n", err)
 		return err.Error()
 	}
 	return string(jsonstr)