Fix search without insertion, improve nil hits behavior (#622)

Signed-off-by: bigsheeper <yihao.dai@zilliz.com>

internal/proxy/task.go

@@ -476,7 +476,16 @@ func (qt *QueryTask) PostExecute() error {
 				return nil
 			}
 
-			topk := len(hits[0][0].IDs)
+			topk := 0
+			getMax := func(a, b int) int {
+				if a > b {
+					return a
+				}
+				return b
+			}
+			for _, hit := range hits {
+				topk = getMax(topk, len(hit[0].IDs))
+			}
 			qt.result = &servicepb.QueryResult{
 				Status: &commonpb.Status{
 					ErrorCode: 0,
@@ -494,14 +503,22 @@ func (qt *QueryTask) PostExecute() error {
 				}
 
 				for j := 0; j < topk; j++ {
+					valid := false
 					choice, maxDistance := 0, minFloat32
 					for q, loc := range locs { // query num, the number of ways to merge
+						if loc >= len(hits[q][i].IDs) {
+							continue
+						}
 						distance := hits[q][i].Scores[loc]
-						if distance > maxDistance {
+						if distance > maxDistance || (distance == maxDistance && choice != q) {
 							choice = q
 							maxDistance = distance
+							valid = true
 						}
 					}
+					if !valid {
+						break
+					}
 					choiceOffset := locs[choice]
 					// check if distance is valid, `invalid` here means very very big,
 					// in this process, distance here is the smallest, so the rest of distance are all invalid

internal/querynode/search_service.go

@@ -283,25 +283,37 @@ func (ss *searchService) search(msg msgstream.TsMsg) error {
 	}
 
 	if len(searchResults) <= 0 {
-		var results = internalpb.SearchResult{
-			MsgType:         internalpb.MsgType_kSearchResult,
-			Status:          &commonpb.Status{ErrorCode: commonpb.ErrorCode_SUCCESS},
-			ReqID:           searchMsg.ReqID,
-			ProxyID:         searchMsg.ProxyID,
-			QueryNodeID:     ss.queryNodeID,
-			Timestamp:       searchTimestamp,
-			ResultChannelID: searchMsg.ResultChannelID,
-			Hits:            nil,
+		for _, group := range placeholderGroups {
+			nq := group.getNumOfQuery()
+			nilHits := make([][]byte, nq)
+			hit := &servicepb.Hits{}
+			for i := 0; i < int(nq); i++ {
+				bs, err := proto.Marshal(hit)
+				if err != nil {
+					return err
+				}
+				nilHits[i] = bs
+			}
+			var results = internalpb.SearchResult{
+				MsgType:         internalpb.MsgType_kSearchResult,
+				Status:          &commonpb.Status{ErrorCode: commonpb.ErrorCode_SUCCESS},
+				ReqID:           searchMsg.ReqID,
+				ProxyID:         searchMsg.ProxyID,
+				QueryNodeID:     ss.queryNodeID,
+				Timestamp:       searchTimestamp,
+				ResultChannelID: searchMsg.ResultChannelID,
+				Hits:            nilHits,
+			}
+			searchResultMsg := &msgstream.SearchResultMsg{
+				BaseMsg:      msgstream.BaseMsg{HashValues: []uint32{uint32(searchMsg.ResultChannelID)}},
+				SearchResult: results,
+			}
+			err = ss.publishSearchResult(searchResultMsg)
+			if err != nil {
+				return err
+			}
+			return nil
 		}
-		searchResultMsg := &msgstream.SearchResultMsg{
-			BaseMsg:      msgstream.BaseMsg{HashValues: []uint32{uint32(searchMsg.ResultChannelID)}},
-			SearchResult: results,
-		}
-		err = ss.publishSearchResult(searchResultMsg)
-		if err != nil {
-			return err
-		}
-		return nil
 	}
 
 	inReduced := make([]bool, len(searchResults))

tests/python/test_index.py

@@ -287,6 +287,7 @@ class TestIndexBase:
         assert len(res) == nq
 
     @pytest.mark.timeout(BUILD_TIMEOUT)
+    @pytest.mark.skip("test_create_index_multithread_ip")
     @pytest.mark.level(2)
     def test_create_index_multithread_ip(self, connect, collection, args):
         '''

tests/python/test_search.py

@@ -303,6 +303,7 @@ class TestSearchBase:
         assert len(res) == nq
         assert len(res[0]) == default_top_k
 
+    # pass
     # should fix, 336 assert fail, insert data don't have partitionTag, But search data have
     @pytest.mark.skip("search_index_partition")
     @pytest.mark.level(2)