Backport PR #2598 to release/v1.7 for Bugfix NGT flush logic

pkg/agent/core/ngt/handler/grpc/index.go

@@ -64,6 +64,9 @@
 					},
 				}, info.Get())...)
 			code = codes.FailedPrecondition
+		case errors.Is(err, errors.ErrFlushingIsInProgress):
+			err = status.WrapWithAborted("CreateIndex API aborted to process create indexes request due to flushing indices is in progress", err, details...)
+			code = codes.Aborted
 		case errors.Is(err, context.Canceled):
 			err = status.WrapWithCanceled(fmt.Sprintf("CreateIndex API canceled to create indexes pool_size = %d, error: %v", c.GetPoolSize(), err), err, details...)
 			code = codes.Canceled
@@ -149,6 +152,9 @@
 					},
 				}, info.Get())...)
 			code = codes.FailedPrecondition
+		case errors.Is(err, errors.ErrFlushingIsInProgress):
+			err = status.WrapWithAborted("CreateAndSaveIndex API aborted to process create indexes request due to flushing indices is in progress", err, details...)
+			code = codes.Aborted
 		case errors.Is(err, context.Canceled):
 			err = status.WrapWithCanceled(fmt.Sprintf("CreateAndSaveIndex API canceled to create indexes pool_size = %d, error: %v", c.GetPoolSize(), err), err, details...)
 			code = codes.Canceled

pkg/agent/core/ngt/service/ngt.go

@@ -260,6 +260,26 @@
 	return n, nil
 }
 
+func (n *ngt) copyNGT(src *ngt) {
+	// instances
+	n.core = src.core
+	n.kvs = src.kvs
+	n.fmap = src.fmap
+	n.vq = src.vq
+
+	// counters
+	n.wfci = src.wfci
+	n.nobic = src.nobic
+	n.nopvq = atomic.Uint64{}
+
+	// paths
+	n.path = src.path
+	n.tmpPath = src.tmpPath
+	n.oldPath = src.oldPath
+	n.basePath = src.basePath
+	n.brokenPath = src.brokenPath
+}
+
 // migrate migrates the index directory from old to new under the input path if necessary.
 // Migration happens when the path is not empty and there is no `path/origin` directory,
 // which indicates that the user has NOT been using CoW mode and the index directory is not migrated yet.
@@ -908,7 +928,7 @@
 				}
 				return ctx.Err()
 			case <-tick.C:
-				if n.vq.IVQLen() >= n.alen {
+				if n.vq != nil && !n.IsFlushing() && n.vq.IVQLen() >= n.alen {
 					err = n.CreateIndex(ctx, n.poolSize)
 				}
 			case <-limit.C:
@@ -1242,14 +1262,12 @@
 	if err != nil {
 		log.Errorf("failed to flushing vector to ngt index in delete kvs. error: %v", err)
 	}
-	n.kvs = nil
-	n.vq = nil
 
 	// gc
 	runtime.GC()
 	atomic.AddUint64(&n.nogce, 1)
 
-	if n.inMem {
+	if !n.inMem {
 		// delete file
 		err = file.DeleteDir(ctx, n.path)
 		if err != nil {
@@ -1265,30 +1283,14 @@
 		}
 	}
 
-	nkvs := kvs.New(kvs.WithConcurrency(n.kvsdbConcurrency))
-
-	nvq, err := vqueue.New()
-	if err != nil {
-		log.Errorf("failed to create new vector vector queue. error: %v", err)
-	}
-
 	// renew instance
 	nn, err := newNGT(n.cfg, n.opts...)
 	if err != nil {
 		return err
 	}
-	nn.kvs = nkvs
-	nn.vq = nvq
-
-	// Regenerate with flags set
-	nn.flushing.Store(true)
-	nn.indexing.Store(true)
-	defer nn.flushing.Store(false)
-	defer nn.indexing.Store(false)
+	n.copyNGT(nn)
 
-	n = nn
-
-	return nil
+	return n.loadStatistics()
 }
 
 func (n *ngt) CreateIndex(ctx context.Context, poolSize uint32) (err error) {
@@ -1299,8 +1301,11 @@
 		}
 	}()
 
-	if n.isReadReplica {
+	switch {
+	case n.isReadReplica:
 		return errors.ErrWriteOperationToReadReplica
+	case n.IsFlushing():
+		return errors.ErrFlushingIsInProgress
 	}
 
 	ic := n.vq.IVQLen() + n.vq.DVQLen()
@@ -1428,6 +1433,10 @@
 			return err
 		}
 	}
+	return n.loadStatistics()
+}
+
+func (n *ngt) loadStatistics() error {
 	if n.IsStatisticsEnabled() {
 		log.Info("loading index statistics to cache")
 		stats, err := n.core.GetGraphStatistics(core.AdditionalStatistics)
@@ -1471,8 +1480,7 @@
 			IndegreeHistogram:                stats.IndegreeHistogram,
 		})
 	}
-
-	return err
+	return nil
 }
 
 func (n *ngt) removeInvalidIndex(ctx context.Context) {
@@ -1941,15 +1949,24 @@
 }
 
 func (n *ngt) Len() uint64 {
-	return n.kvs.Len()
+	if n.kvs != nil && !n.IsFlushing() {
+		return n.kvs.Len()
+	}
+	return 0
 }
 
 func (n *ngt) InsertVQueueBufferLen() uint64 {
-	return uint64(n.vq.IVQLen())
+	if n.vq != nil && !n.IsFlushing() {
+		return uint64(n.vq.IVQLen())
+	}
+	return 0
 }
 
 func (n *ngt) DeleteVQueueBufferLen() uint64 {
-	return uint64(n.vq.DVQLen())
+	if n.vq != nil && !n.IsFlushing() {
+		return uint64(n.vq.DVQLen())
+	}
+	return 0
 }
 
 func (n *ngt) GetDimensionSize() int {