enhance: add debug log on collection load

internal/querycoordv2/balance/score_based_balancer.go

@@ -524,6 +524,7 @@ func (b *ScoreBasedBalancer) balanceSegments(ctx context.Context, br *balanceRep
 		}
 
 		log.Info("Handle stopping nodes",
+			zap.Any("replica", replica.GetID()),
 			zap.Any("stopping nodes", roNodes),
 			zap.Any("available nodes", rwNodes),
 		)

internal/querycoordv2/job/job_load.go

@@ -88,6 +88,11 @@ func (job *LoadCollectionJob) Execute() error {
 
 	log := log.Ctx(job.ctx).With(zap.Int64("collectionID", req.GetCollectionId()))
 	meta.GlobalFailedLoadCache.Remove(req.GetCollectionId())
+	log.Info("start load collection job",
+		zap.Int("replicaConfigs", len(req.GetReplicas())),
+		zap.Int("channelNum", len(vchannels)),
+		zap.Int("partitionNum", len(req.GetPartitionIds())),
+	)
 
 	// 1. create replica if not exist
 	if _, err := utils.SpawnReplicasWithReplicaConfig(job.ctx, job.meta, meta.SpawnWithReplicaConfigParams{
@@ -151,6 +156,7 @@ func (job *LoadCollectionJob) Execute() error {
 		}
 	}
 	if len(toReleasePartitions) > 0 {
+		log.Info("release stale partitions", zap.Int64s("toReleasePartitions", toReleasePartitions))
 		job.targetObserver.ReleasePartition(req.GetCollectionId(), toReleasePartitions...)
 		if err := job.meta.CollectionManager.RemovePartition(job.ctx, req.GetCollectionId(), toReleasePartitions...); err != nil {
 			return errors.Wrap(err, "failed to remove partitions")
@@ -177,7 +183,9 @@ func (job *LoadCollectionJob) Execute() error {
 	}
 
 	// 6. register load task into collection observer
-	job.collectionObserver.LoadPartitions(ctx, req.GetCollectionId(), incomingPartitions.Collect())
+	incomingPartitionIDs := incomingPartitions.Collect()
+	log.Info("trigger collection observer load", zap.Int64s("incomingPartitions", incomingPartitionIDs))
+	job.collectionObserver.LoadPartitions(ctx, req.GetCollectionId(), incomingPartitionIDs)
 
 	// 7. wait for partition released if any partition is released
 	if len(toReleasePartitions) > 0 {
@@ -193,5 +201,6 @@ func (job *LoadCollectionJob) Execute() error {
 		}
 		log.Info("wait for partition released done", zap.Int64s("toReleasePartitions", toReleasePartitions))
 	}
+	log.Info("load collection job finished successfully")
 	return nil
 }

internal/querycoordv2/server.go

@@ -678,6 +678,7 @@ func (s *Server) watchNodes(revision int64) {
 
 			switch event.EventType {
 			case sessionutil.SessionAddEvent:
+				log.Info("adding a node")
 				s.nodeMgr.Add(session.NewNodeInfo(session.ImmutableNodeInfo{
 					NodeID:   nodeID,
 					Address:  addr,

internal/querynodev2/services.go

@@ -234,9 +234,25 @@
 		return merr.Status(err), nil
 	}
 
-	_, exist := node.delegators.Get(channel.GetChannelName())
+	current, exist := node.delegators.Get(channel.GetChannelName())
 	if exist {
-		log.Info("channel already subscribed")
+		var (
+			loadedRatio      float64
+			queryViewVersion int64
+			serviceable      bool
+		)
+		if view := current.GetChannelQueryView(); view != nil {
+			loadedRatio = view.GetLoadedRatio()
+			queryViewVersion = view.GetVersion()
+			serviceable = view.Serviceable()
+		}
+		log.Info("channel already subscribed",
+			zap.Int64("delegatorVersion", delegator.Version()),
+			zap.Float64("loadedRatio", loadedRatio),
+			zap.Bool("serviceable", serviceable),
+			zap.Int64("queryViewVersion", queryViewVersion),
+			zap.Time("tSafe", tsoutil.PhysicalTime(delegator.GetTSafe())),
+		)
 		return merr.Success(), nil
 	}