Remove v2 store apply logic

server/etcdserver/server.go

@@ -141,7 +141,6 @@ type ServerV2 interface {
 	Leader() types.ID
 
 	// Do takes a V2 request and attempts to fulfill it, returning a Response.
-	Do(ctx context.Context, r pb.Request) (Response, error)
 	ClientCertAuthEnabled() bool
 }
 
@@ -247,8 +246,6 @@ type EtcdServer struct {
 	v2store     v2store.Store
 	snapshotter *snap.Snapshotter
 
-	applyV2 ApplierV2
-
 	uberApply apply.UberApplier
 
 	applyWait wait.WaitTime
@@ -338,7 +335,6 @@ func NewServer(cfg config.ServerConfig) (srv *EtcdServer, err error) {
 	}
 	serverID.With(prometheus.Labels{"server_id": b.cluster.nodeID.String()}).Set(1)
 	srv.cluster.SetVersionChangedNotifier(srv.clusterVersionChanged)
-	srv.applyV2 = NewApplierV2(cfg.Logger, srv.v2store, srv.cluster)
 
 	srv.be = b.storage.backend.be
 	srv.beHooks = b.storage.backend.beHooks
@@ -1897,22 +1893,12 @@ func (s *EtcdServer) applyEntryNormal(e *raftpb.Entry) {
 	}
 
 	var raftReq pb.InternalRaftRequest
-	if !pbutil.MaybeUnmarshal(&raftReq, e.Data) { // backward compatible
-		var r pb.Request
-		rp := &r
-		pbutil.MustUnmarshal(rp, e.Data)
-		s.lg.Debug("applyEntryNormal", zap.Stringer("V2request", rp))
-		s.w.Trigger(r.ID, s.applyV2Request((*RequestV2)(rp), shouldApplyV3))
+	if !pbutil.MaybeUnmarshal(&raftReq, e.Data) || raftReq.V2 != nil {
+		s.lg.Error("Unsupported v2 entry encountered. Skipping...")
 		return
 	}
 	s.lg.Debug("applyEntryNormal", zap.Stringer("raftReq", &raftReq))
 
-	if raftReq.V2 != nil {
-		req := (*RequestV2)(raftReq.V2)
-		s.w.Trigger(req.ID, s.applyV2Request(req, shouldApplyV3))
-		return
-	}
-
 	id := raftReq.ID
 	if id == 0 {
 		if raftReq.Header == nil {
@@ -2267,46 +2253,6 @@ func (s *EtcdServer) monitorCompactHash() {
 	}
 }
 
-func (s *EtcdServer) updateClusterVersionV2(ver string) {
-	lg := s.Logger()
-
-	if s.cluster.Version() == nil {
-		lg.Info(
-			"setting up initial cluster version using v2 API",
-			zap.String("cluster-version", version.Cluster(ver)),
-		)
-	} else {
-		lg.Info(
-			"updating cluster version using v2 API",
-			zap.String("from", version.Cluster(s.cluster.Version().String())),
-			zap.String("to", version.Cluster(ver)),
-		)
-	}
-
-	req := pb.Request{
-		Method: "PUT",
-		Path:   membership.StoreClusterVersionKey(),
-		Val:    ver,
-	}
-
-	ctx, cancel := context.WithTimeout(s.ctx, s.Cfg.ReqTimeout())
-	_, err := s.Do(ctx, req)
-	cancel()
-
-	switch err {
-	case nil:
-		lg.Info("cluster version is updated", zap.String("cluster-version", version.Cluster(ver)))
-		return
-
-	case errors.ErrStopped:
-		lg.Warn("aborting cluster version update; server is stopped", zap.Error(err))
-		return
-
-	default:
-		lg.Warn("failed to update cluster version", zap.Error(err))
-	}
-}
-
 func (s *EtcdServer) updateClusterVersionV3(ver string) {
 	lg := s.Logger()