fix: collection meta is not removed after gc in DataCoord (#34883)

issue: #34847

Signed-off-by: jaime <yun.zhang@zilliz.com>

internal/datacoord/server.go

@@ -1077,6 +1077,14 @@ func (s *Server) stopServerLoop() {
 // loadCollectionFromRootCoord communicates with RootCoord and asks for collection information.
 // collection information will be added to server meta info.
 func (s *Server) loadCollectionFromRootCoord(ctx context.Context, collectionID int64) error {
+	has, err := s.broker.HasCollection(ctx, collectionID)
+	if err != nil {
+		return err
+	}
+	if !has {
+		return merr.WrapErrCollectionNotFound(collectionID)
+	}
+
 	resp, err := s.broker.DescribeCollectionInternal(ctx, collectionID)
 	if err != nil {
 		return err

internal/datacoord/server_test.go

@@ -3322,6 +3322,57 @@ func TestDataCoord_EnableActiveStandby(t *testing.T) {
 	}, time.Second*5, time.Millisecond*100)
 }
 
+func TestLoadCollectionFromRootCoord(t *testing.T) {
+	broker := broker.NewMockBroker(t)
+	s := &Server{
+		broker: broker,
+		meta:   &meta{collections: make(map[UniqueID]*collectionInfo)},
+	}
+
+	t.Run("has collection fail with error", func(t *testing.T) {
+		broker.EXPECT().HasCollection(mock.Anything, mock.Anything).
+			Return(false, errors.New("has collection error")).Once()
+		err := s.loadCollectionFromRootCoord(context.TODO(), 0)
+		assert.Error(t, err, "has collection error")
+	})
+
+	t.Run("has collection with not found", func(t *testing.T) {
+		broker.EXPECT().HasCollection(mock.Anything, mock.Anything).Return(false, nil).Once()
+		err := s.loadCollectionFromRootCoord(context.TODO(), 0)
+		assert.Error(t, err)
+		assert.True(t, errors.Is(err, merr.ErrCollectionNotFound))
+	})
+
+	broker.EXPECT().HasCollection(mock.Anything, mock.Anything).Return(true, nil)
+
+	t.Run("describeCollectionInternal fail", func(t *testing.T) {
+		broker.EXPECT().DescribeCollectionInternal(mock.Anything, mock.Anything).
+			Return(nil, errors.New("describeCollectionInternal error")).Once()
+		err := s.loadCollectionFromRootCoord(context.TODO(), 0)
+		assert.Error(t, err, "describeCollectionInternal error")
+	})
+
+	broker.EXPECT().DescribeCollectionInternal(mock.Anything, mock.Anything).Return(&milvuspb.DescribeCollectionResponse{
+		CollectionID: 1,
+	}, nil).Twice()
+
+	t.Run("ShowPartitionsInternal fail", func(t *testing.T) {
+		broker.EXPECT().ShowPartitionsInternal(mock.Anything, mock.Anything).
+			Return(nil, errors.New("ShowPartitionsInternal error")).Once()
+		err := s.loadCollectionFromRootCoord(context.TODO(), 0)
+		assert.Error(t, err, "ShowPartitionsInternal error")
+	})
+
+	broker.EXPECT().ShowPartitionsInternal(mock.Anything, mock.Anything).Return([]int64{2000}, nil).Once()
+	t.Run("ok", func(t *testing.T) {
+		err := s.loadCollectionFromRootCoord(context.TODO(), 0)
+		assert.NoError(t, err)
+		assert.Equal(t, 1, len(s.meta.collections))
+		_, ok := s.meta.collections[1]
+		assert.True(t, ok)
+	})
+}
+
 func TestUpdateAutoBalanceConfigLoop(t *testing.T) {
 	Params.Save(Params.DataCoordCfg.CheckAutoBalanceConfigInterval.Key, "1")
 	defer Params.Reset(Params.DataCoordCfg.CheckAutoBalanceConfigInterval.Key)