review

pkg/protect/protect.go

@@ -0,0 +1,71 @@
+package protect
+
+import (
+	"fmt"
+	"github.com/apache/servicecomb-service-center/pkg/util"
+	"net/http"
+	"time"
+
+	"github.com/apache/servicecomb-service-center/server/config"
+
+	"github.com/apache/servicecomb-service-center/pkg/log"
+)
+
+/**
+for restart service center, set a restartProtectInterval time window to return RestartProtectHttpCode on discovery apis,
+indicating that sdk not need to clear cache
+*/
+
+var (
+	isWithinProtection        bool
+	startupTimestamp          int64
+	enableInstanceNullProtect bool
+	restartProtectInterval    time.Duration
+	RestartProtectHttpCode    int
+	validProtectCode          = []int{http.StatusNotModified, http.StatusUnprocessableEntity, http.StatusInternalServerError}
+)
+
+const (
+	maxInterval                   = 120 * time.Second
+	minInterval                   = 0 * time.Second
+	defaultRestartProtectInterval = 120 * time.Second
+)
+
+func Init() {
+	enableInstanceNullProtect = config.GetBool("instance_null_protect.enable", false)
+	restartProtectInterval = time.Duration(config.GetInt("instance_null_protect.restart_protect_interval", 120)) * time.Second
+	if restartProtectInterval > maxInterval || restartProtectInterval < minInterval {
+		log.Warn(fmt.Sprintf("invalid instance_null_protect.restart_protect_interval: %d,"+
+			" must between %d-%ds inclusively", restartProtectInterval, minInterval, maxInterval))
+		restartProtectInterval = defaultRestartProtectInterval
+	}
+	RestartProtectHttpCode = config.GetInt("instance_null_protect.http_status", http.StatusNotModified)
+	if !util.Contains(validProtectCode, RestartProtectHttpCode) {
+		log.Warn(fmt.Sprintf("invalid instance_null_protect.http_status: %d, must be %v", RestartProtectHttpCode, validProtectCode))
+		RestartProtectHttpCode = http.StatusNotModified
+	}
+
+	log.Info(fmt.Sprintf("instance_null_protect.enable: %t", enableInstanceNullProtect))
+	log.Info(fmt.Sprintf("instance_null_protect.restart_protect_interval: %d", restartProtectInterval))
+	log.Info(fmt.Sprintf("instance_null_protect.http_status: %d", RestartProtectHttpCode))
+	startupTimestamp = time.Now().UnixNano()
+	isWithinProtection = true
+}
+
+func IsWithinRestartProtection() bool {
+	if !enableInstanceNullProtect {
+		return false
+	}
+
+	if !isWithinProtection {
+		return false
+	}
+
+	if time.Now().Add(-restartProtectInterval).UnixNano() > startupTimestamp {
+		log.Info("restart protection stop")
+		isWithinProtection = false
+		return false
+	}
+	log.Info("within restart protection")
+	return true
+}

pkg/rest/first_launch_test.go → pkg/protect/protect_test.go

@@ -1,4 +1,4 @@
-package rest
+package protect
 
 import (
 	"testing"

pkg/util/util.go

@@ -194,3 +194,19 @@ func GeneratePassword() (string, error) {
 	}
 	return pass, nil
 }
+
+// Contains reports whether v is present in s.
+func Contains[S ~[]E, E comparable](s S, v E) bool {
+	return Index(s, v) >= 0
+}
+
+// Index returns the index of the first occurrence of v in s,
+// or -1 if not present.
+func Index[S ~[]E, E comparable](s S, v E) int {
+	for i := range s {
+		if v == s[i] {
+			return i
+		}
+	}
+	return -1
+}

pkg/util/util_test.go

@@ -17,6 +17,7 @@
 package util
 
 import (
+	"net/http"
 	"os"
 	"testing"
 
@@ -184,3 +185,9 @@ func TestGeneratePassword(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, 8, len(password), password)
 }
+
+func TestContains(t *testing.T) {
+	slc := []int{http.StatusNotModified, http.StatusUnprocessableEntity, http.StatusInternalServerError}
+	assert.True(t, Contains(slc, 304))
+	assert.False(t, Contains(slc, 100))
+}

server/resource/disco/instance_resource.go

@@ -19,6 +19,7 @@ package disco
 
 import (
 	"fmt"
+	"github.com/apache/servicecomb-service-center/pkg/protect"
 	"io"
 	"net/http"
 	"strings"
@@ -168,8 +169,8 @@ func (s *InstanceResource) FindInstances(w http.ResponseWriter, r *http.Request)
 		w.WriteHeader(http.StatusNotModified)
 		return
 	}
-	if len(resp.Instances) == 0 && rest.IsWithinRestartProtection() {
-		w.WriteHeader(rest.RestartProtectHttpCode)
+	if len(resp.Instances) == 0 && protect.IsWithinRestartProtection() {
+		w.WriteHeader(protect.RestartProtectHttpCode)
 		return
 	}
 	rest.WriteResponse(w, r, nil, resp)
@@ -271,8 +272,8 @@ func (s *InstanceResource) ListInstance(w http.ResponseWriter, r *http.Request)
 		w.WriteHeader(http.StatusNotModified)
 		return
 	}
-	if len(resp.Instances) == 0 && rest.IsWithinRestartProtection() {
-		w.WriteHeader(rest.RestartProtectHttpCode)
+	if len(resp.Instances) == 0 && protect.IsWithinRestartProtection() {
+		w.WriteHeader(protect.RestartProtectHttpCode)
 		return
 	}
 	rest.WriteResponse(w, r, nil, resp)

server/server.go

@@ -20,11 +20,11 @@ package server
 import (
 	"context"
 	"crypto/tls"
+	"github.com/apache/servicecomb-service-center/pkg/protect"
 	"os"
 
 	"github.com/gofiber/fiber/v2"
 
-	"github.com/apache/servicecomb-service-center/pkg/rest"
 	"github.com/apache/servicecomb-service-center/server/middleware"
 	"github.com/apache/servicecomb-service-center/server/resource/disco"
 
@@ -214,7 +214,7 @@ func (s *ServiceCenterServer) startServices() {
 
 func (s *ServiceCenterServer) startAPIService() {
 	s.APIServer.SetHostPort(s.Endpoint.Host, s.Endpoint.Port)
-	rest.Init()
+	protect.Init()
 	s.APIServer.Start()
 }