enhance: Refine frequent log in datacoord (#33449)

This PR changes:
- Frequent `ListIndexes` success log to debug level
- Aggregate collection missing log after collection dropped in
`meta.GetCollectionIndexFilesSize`

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

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

internal/datacoord/index_service.go

@@ -917,7 +917,7 @@ func (s *Server) ListIndexes(ctx context.Context, req *indexpb.ListIndexesReques
 			UserIndexParams: index.UserIndexParams,
 		}
 	})
-	log.Info("List index success")
+	log.Debug("List index success")
 	return &indexpb.ListIndexesResponse{
 		Status:     merr.Success(),
 		IndexInfos: indexInfos,

internal/datacoord/meta.go

@@ -47,6 +47,7 @@ import (
 	"github.com/milvus-io/milvus/pkg/util/paramtable"
 	"github.com/milvus-io/milvus/pkg/util/timerecord"
 	"github.com/milvus-io/milvus/pkg/util/tsoutil"
+	"github.com/milvus-io/milvus/pkg/util/typeutil"
 )
 
 type meta struct {
@@ -363,16 +364,21 @@ func (m *meta) GetCollectionIndexFilesSize() uint64 {
 	m.RLock()
 	defer m.RUnlock()
 	var total uint64
+
+	missingCollections := make(typeutil.Set[int64])
 	for _, segmentIdx := range m.indexMeta.GetAllSegIndexes() {
 		coll, ok := m.collections[segmentIdx.CollectionID]
 		if ok {
 			metrics.DataCoordStoredIndexFilesSize.WithLabelValues(coll.DatabaseName,
 				fmt.Sprint(segmentIdx.CollectionID), fmt.Sprint(segmentIdx.SegmentID)).Set(float64(segmentIdx.IndexSize))
 			total += segmentIdx.IndexSize
 		} else {
-			log.Warn("not found database name", zap.Int64("collectionID", segmentIdx.CollectionID))
+			missingCollections.Insert(segmentIdx.CollectionID)
 		}
 	}
+	if missingCollections.Len() > 0 {
+		log.Warn("collection info not found when calculating index file sizes", zap.Int64s("collectionIDs", missingCollections.Collect()))
+	}
 	return total
 }