[#1516] traverser: Check for placement vector out of range

Placement vector may contain fewer nodes count than it required by policy
due to the outage of the one of the node.

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

cmd/frostfs-adm/internal/commonflags/flags.go

@@ -20,6 +20,7 @@ const (
 	AlphabetWalletsFlagDesc = "Path to alphabet wallets dir"
 
 	LocalDumpFlag                   = "local-dump"
+	ProtoConfigPath                 = "protocol"
 	ContractsInitFlag               = "contracts"
 	ContractsInitFlagDesc           = "Path to archive with compiled FrostFS contracts (the default is to fetch the latest release from the official repository)"
 	ContractsURLFlag                = "contracts-url"

cmd/frostfs-adm/internal/modules/morph/constants/const.go

@@ -4,7 +4,6 @@ import "time"
 
 const (
 	ConsensusAccountName = "consensus"
-	ProtoConfigPath      = "protocol"
 
 	// MaxAlphabetNodes is the maximum number of candidates allowed, which is currently limited by the size
 	// of the invocation script.

cmd/frostfs-adm/internal/modules/morph/helper/local_client.go

@@ -8,6 +8,7 @@ import (
 	"sort"
 	"time"
 
+	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-adm/internal/commonflags"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-adm/internal/modules/morph/constants"
 	"github.com/google/uuid"
 	"github.com/nspcc-dev/neo-go/pkg/config"
@@ -47,7 +48,7 @@ type LocalClient struct {
 }
 
 func NewLocalClient(cmd *cobra.Command, v *viper.Viper, wallets []*wallet.Wallet, dumpPath string) (*LocalClient, error) {
-	cfg, err := config.LoadFile(v.GetString(constants.ProtoConfigPath))
+	cfg, err := config.LoadFile(v.GetString(commonflags.ProtoConfigPath))
 	if err != nil {
 		return nil, err
 	}

cmd/frostfs-adm/internal/modules/morph/initialize/initialize_test.go

@@ -62,7 +62,7 @@ func testInitialize(t *testing.T, committeeSize int) {
 	v := viper.GetViper()
 
 	require.NoError(t, generateTestData(testdataDir, committeeSize))
-	v.Set(constants.ProtoConfigPath, filepath.Join(testdataDir, protoFileName))
+	v.Set(commonflags.ProtoConfigPath, filepath.Join(testdataDir, protoFileName))
 
 	// Set to the path or remove the next statement to download from the network.
 	require.NoError(t, Cmd.Flags().Set(commonflags.ContractsInitFlag, contractsPath))

cmd/frostfs-adm/internal/modules/morph/initialize/root.go

@@ -2,7 +2,6 @@ package initialize
 
 import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-adm/internal/commonflags"
-	"git.frostfs.info/TrueCloudLab/frostfs-node/cmd/frostfs-adm/internal/modules/morph/constants"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 )
@@ -32,7 +31,7 @@ var Cmd = &cobra.Command{
 		_ = viper.BindPFlag(commonflags.ContainerFeeInitFlag, cmd.Flags().Lookup(containerFeeCLIFlag))
 		_ = viper.BindPFlag(commonflags.ContainerAliasFeeInitFlag, cmd.Flags().Lookup(containerAliasFeeCLIFlag))
 		_ = viper.BindPFlag(commonflags.WithdrawFeeInitFlag, cmd.Flags().Lookup(withdrawFeeCLIFlag))
-		_ = viper.BindPFlag(constants.ProtoConfigPath, cmd.Flags().Lookup(constants.ProtoConfigPath))
+		_ = viper.BindPFlag(commonflags.ProtoConfigPath, cmd.Flags().Lookup(commonflags.ProtoConfigPath))
 	},
 	RunE: initializeSideChainCmd,
 }
@@ -48,7 +47,7 @@ func initInitCmd() {
 	// Defaults are taken from neo-preodolenie.
 	Cmd.Flags().Uint64(containerFeeCLIFlag, 1000, "Container registration fee")
 	Cmd.Flags().Uint64(containerAliasFeeCLIFlag, 500, "Container alias fee")
-	Cmd.Flags().String(constants.ProtoConfigPath, "", "Path to the consensus node configuration")
+	Cmd.Flags().String(commonflags.ProtoConfigPath, "", "Path to the consensus node configuration")
 	Cmd.Flags().String(commonflags.LocalDumpFlag, "", "Path to the blocks dump file")
 	Cmd.MarkFlagsMutuallyExclusive(commonflags.ContractsInitFlag, commonflags.ContractsURLFlag)
 }

pkg/services/object_manager/placement/traverser.go

@@ -111,14 +111,18 @@ func NewTraverser(opts ...Option) (*Traverser, error) {
 	var rem []int
 	if len(cfg.metrics) > 0 && cfg.nodeState != nil {
 		rem = defaultCopiesVector(cfg.policy)
-		var unsortedVector []netmap.NodeInfo
-		var regularVector []netmap.NodeInfo
+		var unsortedVector, regularVector []netmap.NodeInfo
 		for i := range rem {
-			unsortedVector = append(unsortedVector, ns[i][:rem[i]]...)
-			regularVector = append(regularVector, ns[i][rem[i]:]...)
+			if len(ns[i]) < rem[i] {
+				unsortedVector = append(unsortedVector, ns[i]...)
+			} else {
+				unsortedVector = append(unsortedVector, ns[i][:rem[i]]...)
+				if len(ns[i]) > rem[i] {
+					regularVector = append(regularVector, ns[i][rem[i]:]...)
+				}
+			}
 		}
 		rem = []int{-1, -1}
-
 		sortedVector, err := sortVector(cfg, unsortedVector)
 		if err != nil {
 			return nil, err

pkg/services/object_manager/placement/traverser_test.go

@@ -356,6 +356,52 @@ func TestTraverserPriorityMetrics(t *testing.T) {
 		require.Nil(t, next)
 	})
 
+	t.Run("one rep one metric fewer nodes", func(t *testing.T) {
+		selectors := []int{2}
+		replicas := []int{3}
+
+		nodes, cnr := testPlacement(selectors, replicas)
+
+		// Node_0, PK - ip4/0.0.0.0/tcp/0
+		nodes[0][0].SetAttribute("ClusterName", "A")
+		// Node_1, PK - ip4/0.0.0.0/tcp/1
+		nodes[0][1].SetAttribute("ClusterName", "B")
+
+		sdkNode := testNode(5)
+		sdkNode.SetAttribute("ClusterName", "B")
+
+		nodesCopy := copyVectors(nodes)
+
+		m := []Metric{NewAttributeMetric("ClusterName")}
+
+		tr, err := NewTraverser(
+			ForContainer(cnr),
+			UseBuilder(&testBuilder{
+				vectors: nodesCopy,
+			}),
+			WithoutSuccessTracking(),
+			WithPriorityMetrics(m),
+			WithNodeState(&nodeState{
+				node: &sdkNode,
+			}),
+		)
+		require.NoError(t, err)
+
+		// Without priority metric `ClusterName` the order will be:
+		// [ {Node_0 A}, {Node_1 A} ]
+		// With priority metric `ClusterName` and current node in cluster B
+		// the order should be:
+		// [ {Node_1 B}, {Node_0 A} ]
+		next := tr.Next()
+		require.NotNil(t, next)
+		require.Equal(t, 2, len(next))
+		require.Equal(t, "/ip4/0.0.0.0/tcp/1", string(next[0].PublicKey()))
+		require.Equal(t, "/ip4/0.0.0.0/tcp/0", string(next[1].PublicKey()))
+
+		next = tr.Next()
+		require.Nil(t, next)
+	})
+
 	t.Run("two reps two metrics", func(t *testing.T) {
 		selectors := []int{3, 3}
 		replicas := []int{2, 2}