Add TruncatedAt field to meta.ShardGroupInfo

services/meta/data.go

@@ -870,10 +870,12 @@ func NewRetentionPolicyInfo(name string) *RetentionPolicyInfo {
 // ShardGroupByTimestamp returns the shard group in the policy that contains the timestamp.
 func (rpi *RetentionPolicyInfo) ShardGroupByTimestamp(timestamp time.Time) *ShardGroupInfo {
 	for i := range rpi.ShardGroups {
-		if rpi.ShardGroups[i].Contains(timestamp) && !rpi.ShardGroups[i].Deleted() {
+		sgi := &rpi.ShardGroups[i]
+		if sgi.Contains(timestamp) && !sgi.Deleted() && (!sgi.Truncated() || timestamp.Before(sgi.TruncatedAt)) {
 			return &rpi.ShardGroups[i]
 		}
 	}
+
 	return nil
 }
 
@@ -997,11 +999,12 @@ func normalisedShardDuration(sgd, d time.Duration) time.Duration {
 // to be sure that a ShardGroup is not simply missing. If the DeletedAt is set, the system can
 // safely delete any associated shards.
 type ShardGroupInfo struct {
-	ID        uint64
+	ID          uint64
-	StartTime time.Time
+	StartTime   time.Time
-	EndTime   time.Time
+	EndTime     time.Time
-	DeletedAt time.Time
+	DeletedAt   time.Time
-	Shards    []ShardInfo
+	Shards      []ShardInfo
+	TruncatedAt time.Time
 }
 
 // ShardGroupInfos implements sort.Interface on []ShardGroupInfo, based
@@ -1027,6 +1030,11 @@ func (sgi *ShardGroupInfo) Deleted() bool {
 	return !sgi.DeletedAt.IsZero()
 }
 
+// Truncated returns true if this ShardGroup has been truncated (no new writes)
+func (sgi *ShardGroupInfo) Truncated() bool {
+	return !sgi.TruncatedAt.IsZero()
+}
+
 // clone returns a deep copy of sgi.
 func (sgi ShardGroupInfo) clone() ShardGroupInfo {
 	other := sgi
@@ -1055,6 +1063,10 @@ func (sgi *ShardGroupInfo) marshal() *internal.ShardGroupInfo {
 		DeletedAt: proto.Int64(MarshalTime(sgi.DeletedAt)),
 	}
 
+	if !sgi.TruncatedAt.IsZero() {
+		pb.TruncatedAt = proto.Int64(MarshalTime(sgi.TruncatedAt))
+	}
+
 	pb.Shards = make([]*internal.ShardInfo, len(sgi.Shards))
 	for i := range sgi.Shards {
 		pb.Shards[i] = sgi.Shards[i].marshal()
@@ -1070,6 +1082,10 @@ func (sgi *ShardGroupInfo) unmarshal(pb *internal.ShardGroupInfo) {
 	sgi.EndTime = UnmarshalTime(pb.GetEndTime())
 	sgi.DeletedAt = UnmarshalTime(pb.GetDeletedAt())
 
+	if pb != nil && pb.TruncatedAt != nil {
+		sgi.TruncatedAt = UnmarshalTime(pb.GetTruncatedAt())
+	}
+
 	if len(pb.GetShards()) > 0 {
 		sgi.Shards = make([]ShardInfo, len(pb.GetShards()))
 		for i, x := range pb.GetShards() {

services/meta/internal/meta.pb.go

@@ -408,6 +408,7 @@ type ShardGroupInfo struct {
 	EndTime          *int64       `protobuf:"varint,3,req,name=EndTime" json:"EndTime,omitempty"`
 	DeletedAt        *int64       `protobuf:"varint,4,req,name=DeletedAt" json:"DeletedAt,omitempty"`
 	Shards           []*ShardInfo `protobuf:"bytes,5,rep,name=Shards" json:"Shards,omitempty"`
+	TruncatedAt      *int64       `protobuf:"varint,6,opt,name=TruncatedAt" json:"TruncatedAt,omitempty"`
 	XXX_unrecognized []byte       `json:"-"`
 }
 
@@ -450,6 +451,13 @@ func (m *ShardGroupInfo) GetShards() []*ShardInfo {
 	return nil
 }
 
+func (m *ShardGroupInfo) GetTruncatedAt() int64 {
+	if m != nil && m.TruncatedAt != nil {
+		return *m.TruncatedAt
+	}
+	return 0
+}
+
 type ShardInfo struct {
 	ID               *uint64       `protobuf:"varint,1,req,name=ID" json:"ID,omitempty"`
 	OwnerIDs         []uint64      `protobuf:"varint,2,rep,name=OwnerIDs" json:"OwnerIDs,omitempty"`

services/meta/internal/meta.proto

@@ -52,6 +52,7 @@ message ShardGroupInfo {
 	required int64 EndTime = 3;
 	required int64 DeletedAt = 4;
 	repeated ShardInfo Shards = 5;
+	optional int64 TruncatedAt = 6;
 }
 
 message ShardInfo {