Fix create meta table fails for compatibility issue (#10703)

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

internal/rootcoord/meta_table.go

@@ -12,6 +12,7 @@
 package rootcoord
 
 import (
+	"bytes"
 	"fmt"
 	"path"
 	"strconv"
@@ -137,6 +138,10 @@ func (mt *MetaTable) reloadFromKV() error {
 	}
 
 	for _, value := range values {
+		if bytes.Equal([]byte(value), suffixSnapshotTombstone) {
+			// backward compatibility, IndexMeta used to be in SnapshotKV
+			continue
+		}
 		proxyMeta := pb.ProxyMeta{}
 		err = proto.Unmarshal([]byte(value), &proxyMeta)
 		if err != nil {
@@ -165,6 +170,10 @@ func (mt *MetaTable) reloadFromKV() error {
 		return err
 	}
 	for _, value := range values {
+		if bytes.Equal([]byte(value), suffixSnapshotTombstone) {
+			// backward compatibility, IndexMeta used to be in SnapshotKV
+			continue
+		}
 		segmentIndexInfo := pb.SegmentIndexInfo{}
 		err = proto.Unmarshal([]byte(value), &segmentIndexInfo)
 		if err != nil {
@@ -197,6 +206,10 @@ func (mt *MetaTable) reloadFromKV() error {
 		return err
 	}
 	for _, value := range values {
+		if bytes.Equal([]byte(value), suffixSnapshotTombstone) {
+			// backward compatibility, IndexMeta used to be in SnapshotKV
+			continue
+		}
 		meta := pb.IndexInfo{}
 		err = proto.Unmarshal([]byte(value), &meta)
 		if err != nil {

internal/rootcoord/meta_table_test.go

@@ -14,12 +14,14 @@ import (
 	"errors"
 	"fmt"
 	"math/rand"
+	"path"
 	"testing"
 	"time"
 
 	"github.com/golang/protobuf/proto"
 	"github.com/milvus-io/milvus/internal/kv"
 	etcdkv "github.com/milvus-io/milvus/internal/kv/etcd"
+	memkv "github.com/milvus-io/milvus/internal/kv/mem"
 	"github.com/milvus-io/milvus/internal/proto/commonpb"
 	pb "github.com/milvus-io/milvus/internal/proto/etcdpb"
 	"github.com/milvus-io/milvus/internal/proto/schemapb"
@@ -1231,3 +1233,27 @@ func TestMetaWithTimestamp(t *testing.T) {
 	_, err = mt.GetPartitionByName(2, partName2, tsoStart)
 	assert.NotNil(t, err)
 }
+
+func TestFixIssue10540(t *testing.T) {
+	rand.Seed(time.Now().UnixNano())
+	randVal := rand.Int()
+	Params.Init()
+	rootPath := fmt.Sprintf("/test/meta/%d", randVal)
+
+	etcdCli, err := clientv3.New(clientv3.Config{Endpoints: Params.EtcdEndpoints})
+	assert.Nil(t, err)
+	defer etcdCli.Close()
+
+	skv, err := newMetaSnapshot(etcdCli, rootPath, TimestampPrefix, 7)
+	assert.Nil(t, err)
+	assert.NotNil(t, skv)
+	//txnKV := etcdkv.NewEtcdKVWithClient(etcdCli, rootPath)
+	txnKV := memkv.NewMemoryKV()
+	// compose rc7 legace tombstone cases
+	txnKV.Save(path.Join(ProxyMetaPrefix, "1"), string(suffixSnapshotTombstone))
+	txnKV.Save(path.Join(SegmentIndexMetaPrefix, "2"), string(suffixSnapshotTombstone))
+	txnKV.Save(path.Join(IndexMetaPrefix, "3"), string(suffixSnapshotTombstone))
+
+	_, err = NewMetaTable(txnKV, skv)
+	assert.Nil(t, err)
+}