Fix retryKeepAlive assertion panic (#24667)

Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>

internal/util/sessionutil/session_util.go

@@ -794,7 +794,7 @@ func (s *Session) LivenessCheck(ctx context.Context, callback func()) {
 					case mvccpb.PUT:
 						log.Info("register session success", zap.String("role", s.ServerName), zap.String("key", string(event.Kv.Key)))
 					case mvccpb.DELETE:
-						if s.retryKeepAlive.Load().(bool) {
+						if s.isRetryingKeepAlive() {
 							log.Info("session key is deleted during re register, ignore this DELETE event", zap.String("role", s.ServerName), zap.String("key", string(event.Kv.Key)))
 							continue
 						}
@@ -873,6 +873,14 @@ func (s *Session) SetEnableRetryKeepAlive(enable bool) {
 	s.enableRetryKeepAlive = enable
 }
 
+func (s *Session) isRetryingKeepAlive() bool {
+	v, ok := s.retryKeepAlive.Load().(bool)
+	if !ok {
+		return false
+	}
+	return v
+}
+
 func (s *Session) safeCloseLiveCh() {
 	s.liveChOnce.Do(func() {
 		close(s.liveCh)

internal/util/sessionutil/session_util_test.go

@@ -797,6 +797,29 @@ func (s *SessionSuite) TestDisconnected() {
 	}
 }
 
+func (s *SessionSuite) TestRetryKeepAlive() {
+	st := &Session{}
+	st.retryKeepAlive.Store(true)
+	sf := &Session{}
+	sf.retryKeepAlive.Store(false)
+
+	cases := []struct {
+		tag    string
+		input  *Session
+		expect bool
+	}{
+		{"not_set", &Session{}, false},
+		{"set_true", st, true},
+		{"set_false", sf, false},
+	}
+
+	for _, c := range cases {
+		s.Run(c.tag, func() {
+			s.Equal(c.expect, c.input.isRetryingKeepAlive())
+		})
+	}
+}
+
 func (s *SessionSuite) TestGoingStop() {
 	ctx := context.Background()
 	sdisconnect := NewSession(ctx, s.metaRoot, s.client)