diff --git a/vendor/go.etcd.io/etcd/etcdserver/apply.go b/vendor/go.etcd.io/etcd/etcdserver/apply.go
new file mode 100644
index 0000000..1f06ad0
--- /dev/null
+++ b/vendor/go.etcd.io/etcd/etcdserver/apply.go
@@ -0,0 +1,1019 @@
+// Copyright 2016 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package etcdserver
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"sort"
+	"time"
+
+	"go.etcd.io/etcd/auth"
+	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
+	"go.etcd.io/etcd/lease"
+	"go.etcd.io/etcd/mvcc"
+	"go.etcd.io/etcd/mvcc/mvccpb"
+	"go.etcd.io/etcd/pkg/types"
+
+	"github.com/gogo/protobuf/proto"
+	"go.uber.org/zap"
+)
+
+const (
+	warnApplyDuration = 100 * time.Millisecond
+)
+
+type applyResult struct {
+	resp proto.Message
+	err  error
+	// physc signals the physical effect of the request has completed in addition
+	// to being logically reflected by the node. Currently only used for
+	// Compaction requests.
+	physc <-chan struct{}
+}
+
+// applierV3 is the interface for processing V3 raft messages
+type applierV3 interface {
+	Apply(r *pb.InternalRaftRequest) *applyResult
+
+	Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error)
+	Range(txn mvcc.TxnRead, r *pb.RangeRequest) (*pb.RangeResponse, error)
+	DeleteRange(txn mvcc.TxnWrite, dr *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error)
+	Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error)
+	Compaction(compaction *pb.CompactionRequest) (*pb.CompactionResponse, <-chan struct{}, error)
+
+	LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error)
+	LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error)
+
+	LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error)
+
+	Alarm(*pb.AlarmRequest) (*pb.AlarmResponse, error)
+
+	Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error)
+
+	AuthEnable() (*pb.AuthEnableResponse, error)
+	AuthDisable() (*pb.AuthDisableResponse, error)
+
+	UserAdd(ua *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error)
+	UserDelete(ua *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error)
+	UserChangePassword(ua *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error)
+	UserGrantRole(ua *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error)
+	UserGet(ua *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error)
+	UserRevokeRole(ua *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error)
+	RoleAdd(ua *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error)
+	RoleGrantPermission(ua *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error)
+	RoleGet(ua *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error)
+	RoleRevokePermission(ua *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error)
+	RoleDelete(ua *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error)
+	UserList(ua *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error)
+	RoleList(ua *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error)
+}
+
+type checkReqFunc func(mvcc.ReadView, *pb.RequestOp) error
+
+type applierV3backend struct {
+	s *EtcdServer
+
+	checkPut   checkReqFunc
+	checkRange checkReqFunc
+}
+
+func (s *EtcdServer) newApplierV3Backend() applierV3 {
+	base := &applierV3backend{s: s}
+	base.checkPut = func(rv mvcc.ReadView, req *pb.RequestOp) error {
+		return base.checkRequestPut(rv, req)
+	}
+	base.checkRange = func(rv mvcc.ReadView, req *pb.RequestOp) error {
+		return base.checkRequestRange(rv, req)
+	}
+	return base
+}
+
+func (s *EtcdServer) newApplierV3() applierV3 {
+	return newAuthApplierV3(
+		s.AuthStore(),
+		newQuotaApplierV3(s, s.newApplierV3Backend()),
+		s.lessor,
+	)
+}
+
+func (a *applierV3backend) Apply(r *pb.InternalRaftRequest) *applyResult {
+	ar := &applyResult{}
+	defer func(start time.Time) {
+		warnOfExpensiveRequest(a.s.getLogger(), start, &pb.InternalRaftStringer{Request: r}, ar.resp, ar.err)
+	}(time.Now())
+
+	// call into a.s.applyV3.F instead of a.F so upper appliers can check individual calls
+	switch {
+	case r.Range != nil:
+		ar.resp, ar.err = a.s.applyV3.Range(nil, r.Range)
+	case r.Put != nil:
+		ar.resp, ar.err = a.s.applyV3.Put(nil, r.Put)
+	case r.DeleteRange != nil:
+		ar.resp, ar.err = a.s.applyV3.DeleteRange(nil, r.DeleteRange)
+	case r.Txn != nil:
+		ar.resp, ar.err = a.s.applyV3.Txn(r.Txn)
+	case r.Compaction != nil:
+		ar.resp, ar.physc, ar.err = a.s.applyV3.Compaction(r.Compaction)
+	case r.LeaseGrant != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseGrant(r.LeaseGrant)
+	case r.LeaseRevoke != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseRevoke(r.LeaseRevoke)
+	case r.LeaseCheckpoint != nil:
+		ar.resp, ar.err = a.s.applyV3.LeaseCheckpoint(r.LeaseCheckpoint)
+	case r.Alarm != nil:
+		ar.resp, ar.err = a.s.applyV3.Alarm(r.Alarm)
+	case r.Authenticate != nil:
+		ar.resp, ar.err = a.s.applyV3.Authenticate(r.Authenticate)
+	case r.AuthEnable != nil:
+		ar.resp, ar.err = a.s.applyV3.AuthEnable()
+	case r.AuthDisable != nil:
+		ar.resp, ar.err = a.s.applyV3.AuthDisable()
+	case r.AuthUserAdd != nil:
+		ar.resp, ar.err = a.s.applyV3.UserAdd(r.AuthUserAdd)
+	case r.AuthUserDelete != nil:
+		ar.resp, ar.err = a.s.applyV3.UserDelete(r.AuthUserDelete)
+	case r.AuthUserChangePassword != nil:
+		ar.resp, ar.err = a.s.applyV3.UserChangePassword(r.AuthUserChangePassword)
+	case r.AuthUserGrantRole != nil:
+		ar.resp, ar.err = a.s.applyV3.UserGrantRole(r.AuthUserGrantRole)
+	case r.AuthUserGet != nil:
+		ar.resp, ar.err = a.s.applyV3.UserGet(r.AuthUserGet)
+	case r.AuthUserRevokeRole != nil:
+		ar.resp, ar.err = a.s.applyV3.UserRevokeRole(r.AuthUserRevokeRole)
+	case r.AuthRoleAdd != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleAdd(r.AuthRoleAdd)
+	case r.AuthRoleGrantPermission != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleGrantPermission(r.AuthRoleGrantPermission)
+	case r.AuthRoleGet != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleGet(r.AuthRoleGet)
+	case r.AuthRoleRevokePermission != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleRevokePermission(r.AuthRoleRevokePermission)
+	case r.AuthRoleDelete != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleDelete(r.AuthRoleDelete)
+	case r.AuthUserList != nil:
+		ar.resp, ar.err = a.s.applyV3.UserList(r.AuthUserList)
+	case r.AuthRoleList != nil:
+		ar.resp, ar.err = a.s.applyV3.RoleList(r.AuthRoleList)
+	default:
+		panic("not implemented")
+	}
+	return ar
+}
+
+func (a *applierV3backend) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (resp *pb.PutResponse, err error) {
+	resp = &pb.PutResponse{}
+	resp.Header = &pb.ResponseHeader{}
+
+	val, leaseID := p.Value, lease.LeaseID(p.Lease)
+	if txn == nil {
+		if leaseID != lease.NoLease {
+			if l := a.s.lessor.Lookup(leaseID); l == nil {
+				return nil, lease.ErrLeaseNotFound
+			}
+		}
+		txn = a.s.KV().Write()
+		defer txn.End()
+	}
+
+	var rr *mvcc.RangeResult
+	if p.IgnoreValue || p.IgnoreLease || p.PrevKv {
+		rr, err = txn.Range(p.Key, nil, mvcc.RangeOptions{})
+		if err != nil {
+			return nil, err
+		}
+	}
+	if p.IgnoreValue || p.IgnoreLease {
+		if rr == nil || len(rr.KVs) == 0 {
+			// ignore_{lease,value} flag expects previous key-value pair
+			return nil, ErrKeyNotFound
+		}
+	}
+	if p.IgnoreValue {
+		val = rr.KVs[0].Value
+	}
+	if p.IgnoreLease {
+		leaseID = lease.LeaseID(rr.KVs[0].Lease)
+	}
+	if p.PrevKv {
+		if rr != nil && len(rr.KVs) != 0 {
+			resp.PrevKv = &rr.KVs[0]
+		}
+	}
+
+	resp.Header.Revision = txn.Put(p.Key, val, leaseID)
+	return resp, nil
+}
+
+func (a *applierV3backend) DeleteRange(txn mvcc.TxnWrite, dr *pb.DeleteRangeRequest) (*pb.DeleteRangeResponse, error) {
+	resp := &pb.DeleteRangeResponse{}
+	resp.Header = &pb.ResponseHeader{}
+	end := mkGteRange(dr.RangeEnd)
+
+	if txn == nil {
+		txn = a.s.kv.Write()
+		defer txn.End()
+	}
+
+	if dr.PrevKv {
+		rr, err := txn.Range(dr.Key, end, mvcc.RangeOptions{})
+		if err != nil {
+			return nil, err
+		}
+		if rr != nil {
+			resp.PrevKvs = make([]*mvccpb.KeyValue, len(rr.KVs))
+			for i := range rr.KVs {
+				resp.PrevKvs[i] = &rr.KVs[i]
+			}
+		}
+	}
+
+	resp.Deleted, resp.Header.Revision = txn.DeleteRange(dr.Key, end)
+	return resp, nil
+}
+
+func (a *applierV3backend) Range(txn mvcc.TxnRead, r *pb.RangeRequest) (*pb.RangeResponse, error) {
+	resp := &pb.RangeResponse{}
+	resp.Header = &pb.ResponseHeader{}
+
+	if txn == nil {
+		txn = a.s.kv.Read()
+		defer txn.End()
+	}
+
+	limit := r.Limit
+	if r.SortOrder != pb.RangeRequest_NONE ||
+		r.MinModRevision != 0 || r.MaxModRevision != 0 ||
+		r.MinCreateRevision != 0 || r.MaxCreateRevision != 0 {
+		// fetch everything; sort and truncate afterwards
+		limit = 0
+	}
+	if limit > 0 {
+		// fetch one extra for 'more' flag
+		limit = limit + 1
+	}
+
+	ro := mvcc.RangeOptions{
+		Limit: limit,
+		Rev:   r.Revision,
+		Count: r.CountOnly,
+	}
+
+	rr, err := txn.Range(r.Key, mkGteRange(r.RangeEnd), ro)
+	if err != nil {
+		return nil, err
+	}
+
+	if r.MaxModRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.ModRevision > r.MaxModRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MinModRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.ModRevision < r.MinModRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MaxCreateRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.CreateRevision > r.MaxCreateRevision }
+		pruneKVs(rr, f)
+	}
+	if r.MinCreateRevision != 0 {
+		f := func(kv *mvccpb.KeyValue) bool { return kv.CreateRevision < r.MinCreateRevision }
+		pruneKVs(rr, f)
+	}
+
+	sortOrder := r.SortOrder
+	if r.SortTarget != pb.RangeRequest_KEY && sortOrder == pb.RangeRequest_NONE {
+		// Since current mvcc.Range implementation returns results
+		// sorted by keys in lexiographically ascending order,
+		// sort ASCEND by default only when target is not 'KEY'
+		sortOrder = pb.RangeRequest_ASCEND
+	}
+	if sortOrder != pb.RangeRequest_NONE {
+		var sorter sort.Interface
+		switch {
+		case r.SortTarget == pb.RangeRequest_KEY:
+			sorter = &kvSortByKey{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_VERSION:
+			sorter = &kvSortByVersion{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_CREATE:
+			sorter = &kvSortByCreate{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_MOD:
+			sorter = &kvSortByMod{&kvSort{rr.KVs}}
+		case r.SortTarget == pb.RangeRequest_VALUE:
+			sorter = &kvSortByValue{&kvSort{rr.KVs}}
+		}
+		switch {
+		case sortOrder == pb.RangeRequest_ASCEND:
+			sort.Sort(sorter)
+		case sortOrder == pb.RangeRequest_DESCEND:
+			sort.Sort(sort.Reverse(sorter))
+		}
+	}
+
+	if r.Limit > 0 && len(rr.KVs) > int(r.Limit) {
+		rr.KVs = rr.KVs[:r.Limit]
+		resp.More = true
+	}
+
+	resp.Header.Revision = rr.Rev
+	resp.Count = int64(rr.Count)
+	resp.Kvs = make([]*mvccpb.KeyValue, len(rr.KVs))
+	for i := range rr.KVs {
+		if r.KeysOnly {
+			rr.KVs[i].Value = nil
+		}
+		resp.Kvs[i] = &rr.KVs[i]
+	}
+	return resp, nil
+}
+
+func (a *applierV3backend) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	isWrite := !isTxnReadonly(rt)
+	txn := mvcc.NewReadOnlyTxnWrite(a.s.KV().Read())
+
+	txnPath := compareToPath(txn, rt)
+	if isWrite {
+		if _, err := checkRequests(txn, rt, txnPath, a.checkPut); err != nil {
+			txn.End()
+			return nil, err
+		}
+	}
+	if _, err := checkRequests(txn, rt, txnPath, a.checkRange); err != nil {
+		txn.End()
+		return nil, err
+	}
+
+	txnResp, _ := newTxnResp(rt, txnPath)
+
+	// When executing mutable txn ops, etcd must hold the txn lock so
+	// readers do not see any intermediate results. Since writes are
+	// serialized on the raft loop, the revision in the read view will
+	// be the revision of the write txn.
+	if isWrite {
+		txn.End()
+		txn = a.s.KV().Write()
+	}
+	a.applyTxn(txn, rt, txnPath, txnResp)
+	rev := txn.Rev()
+	if len(txn.Changes()) != 0 {
+		rev++
+	}
+	txn.End()
+
+	txnResp.Header.Revision = rev
+	return txnResp, nil
+}
+
+// newTxnResp allocates a txn response for a txn request given a path.
+func newTxnResp(rt *pb.TxnRequest, txnPath []bool) (txnResp *pb.TxnResponse, txnCount int) {
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+	resps := make([]*pb.ResponseOp, len(reqs))
+	txnResp = &pb.TxnResponse{
+		Responses: resps,
+		Succeeded: txnPath[0],
+		Header:    &pb.ResponseHeader{},
+	}
+	for i, req := range reqs {
+		switch tv := req.Request.(type) {
+		case *pb.RequestOp_RequestRange:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseRange{}}
+		case *pb.RequestOp_RequestPut:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponsePut{}}
+		case *pb.RequestOp_RequestDeleteRange:
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseDeleteRange{}}
+		case *pb.RequestOp_RequestTxn:
+			resp, txns := newTxnResp(tv.RequestTxn, txnPath[1:])
+			resps[i] = &pb.ResponseOp{Response: &pb.ResponseOp_ResponseTxn{ResponseTxn: resp}}
+			txnPath = txnPath[1+txns:]
+			txnCount += txns + 1
+		default:
+		}
+	}
+	return txnResp, txnCount
+}
+
+func compareToPath(rv mvcc.ReadView, rt *pb.TxnRequest) []bool {
+	txnPath := make([]bool, 1)
+	ops := rt.Success
+	if txnPath[0] = applyCompares(rv, rt.Compare); !txnPath[0] {
+		ops = rt.Failure
+	}
+	for _, op := range ops {
+		tv, ok := op.Request.(*pb.RequestOp_RequestTxn)
+		if !ok || tv.RequestTxn == nil {
+			continue
+		}
+		txnPath = append(txnPath, compareToPath(rv, tv.RequestTxn)...)
+	}
+	return txnPath
+}
+
+func applyCompares(rv mvcc.ReadView, cmps []*pb.Compare) bool {
+	for _, c := range cmps {
+		if !applyCompare(rv, c) {
+			return false
+		}
+	}
+	return true
+}
+
+// applyCompare applies the compare request.
+// If the comparison succeeds, it returns true. Otherwise, returns false.
+func applyCompare(rv mvcc.ReadView, c *pb.Compare) bool {
+	// TODO: possible optimizations
+	// * chunk reads for large ranges to conserve memory
+	// * rewrite rules for common patterns:
+	//	ex. "[a, b) createrev > 0" => "limit 1 /\ kvs > 0"
+	// * caching
+	rr, err := rv.Range(c.Key, mkGteRange(c.RangeEnd), mvcc.RangeOptions{})
+	if err != nil {
+		return false
+	}
+	if len(rr.KVs) == 0 {
+		if c.Target == pb.Compare_VALUE {
+			// Always fail if comparing a value on a key/keys that doesn't exist;
+			// nil == empty string in grpc; no way to represent missing value
+			return false
+		}
+		return compareKV(c, mvccpb.KeyValue{})
+	}
+	for _, kv := range rr.KVs {
+		if !compareKV(c, kv) {
+			return false
+		}
+	}
+	return true
+}
+
+func compareKV(c *pb.Compare, ckv mvccpb.KeyValue) bool {
+	var result int
+	rev := int64(0)
+	switch c.Target {
+	case pb.Compare_VALUE:
+		v := []byte{}
+		if tv, _ := c.TargetUnion.(*pb.Compare_Value); tv != nil {
+			v = tv.Value
+		}
+		result = bytes.Compare(ckv.Value, v)
+	case pb.Compare_CREATE:
+		if tv, _ := c.TargetUnion.(*pb.Compare_CreateRevision); tv != nil {
+			rev = tv.CreateRevision
+		}
+		result = compareInt64(ckv.CreateRevision, rev)
+	case pb.Compare_MOD:
+		if tv, _ := c.TargetUnion.(*pb.Compare_ModRevision); tv != nil {
+			rev = tv.ModRevision
+		}
+		result = compareInt64(ckv.ModRevision, rev)
+	case pb.Compare_VERSION:
+		if tv, _ := c.TargetUnion.(*pb.Compare_Version); tv != nil {
+			rev = tv.Version
+		}
+		result = compareInt64(ckv.Version, rev)
+	case pb.Compare_LEASE:
+		if tv, _ := c.TargetUnion.(*pb.Compare_Lease); tv != nil {
+			rev = tv.Lease
+		}
+		result = compareInt64(ckv.Lease, rev)
+	}
+	switch c.Result {
+	case pb.Compare_EQUAL:
+		return result == 0
+	case pb.Compare_NOT_EQUAL:
+		return result != 0
+	case pb.Compare_GREATER:
+		return result > 0
+	case pb.Compare_LESS:
+		return result < 0
+	}
+	return true
+}
+
+func (a *applierV3backend) applyTxn(txn mvcc.TxnWrite, rt *pb.TxnRequest, txnPath []bool, tresp *pb.TxnResponse) (txns int) {
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+
+	lg := a.s.getLogger()
+	for i, req := range reqs {
+		respi := tresp.Responses[i].Response
+		switch tv := req.Request.(type) {
+		case *pb.RequestOp_RequestRange:
+			resp, err := a.Range(txn, tv.RequestRange)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponseRange).ResponseRange = resp
+		case *pb.RequestOp_RequestPut:
+			resp, err := a.Put(txn, tv.RequestPut)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponsePut).ResponsePut = resp
+		case *pb.RequestOp_RequestDeleteRange:
+			resp, err := a.DeleteRange(txn, tv.RequestDeleteRange)
+			if err != nil {
+				if lg != nil {
+					lg.Panic("unexpected error during txn", zap.Error(err))
+				} else {
+					plog.Panicf("unexpected error during txn: %v", err)
+				}
+			}
+			respi.(*pb.ResponseOp_ResponseDeleteRange).ResponseDeleteRange = resp
+		case *pb.RequestOp_RequestTxn:
+			resp := respi.(*pb.ResponseOp_ResponseTxn).ResponseTxn
+			applyTxns := a.applyTxn(txn, tv.RequestTxn, txnPath[1:], resp)
+			txns += applyTxns + 1
+			txnPath = txnPath[applyTxns+1:]
+		default:
+			// empty union
+		}
+	}
+	return txns
+}
+
+func (a *applierV3backend) Compaction(compaction *pb.CompactionRequest) (*pb.CompactionResponse, <-chan struct{}, error) {
+	resp := &pb.CompactionResponse{}
+	resp.Header = &pb.ResponseHeader{}
+	ch, err := a.s.KV().Compact(compaction.Revision)
+	if err != nil {
+		return nil, ch, err
+	}
+	// get the current revision. which key to get is not important.
+	rr, _ := a.s.KV().Range([]byte("compaction"), nil, mvcc.RangeOptions{})
+	resp.Header.Revision = rr.Rev
+	return resp, ch, err
+}
+
+func (a *applierV3backend) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	l, err := a.s.lessor.Grant(lease.LeaseID(lc.ID), lc.TTL)
+	resp := &pb.LeaseGrantResponse{}
+	if err == nil {
+		resp.ID = int64(l.ID)
+		resp.TTL = l.TTL()
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) LeaseRevoke(lc *pb.LeaseRevokeRequest) (*pb.LeaseRevokeResponse, error) {
+	err := a.s.lessor.Revoke(lease.LeaseID(lc.ID))
+	return &pb.LeaseRevokeResponse{Header: newHeader(a.s)}, err
+}
+
+func (a *applierV3backend) LeaseCheckpoint(lc *pb.LeaseCheckpointRequest) (*pb.LeaseCheckpointResponse, error) {
+	for _, c := range lc.Checkpoints {
+		err := a.s.lessor.Checkpoint(lease.LeaseID(c.ID), c.Remaining_TTL)
+		if err != nil {
+			return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, err
+		}
+	}
+	return &pb.LeaseCheckpointResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) Alarm(ar *pb.AlarmRequest) (*pb.AlarmResponse, error) {
+	resp := &pb.AlarmResponse{}
+	oldCount := len(a.s.alarmStore.Get(ar.Alarm))
+
+	lg := a.s.getLogger()
+	switch ar.Action {
+	case pb.AlarmRequest_GET:
+		resp.Alarms = a.s.alarmStore.Get(ar.Alarm)
+	case pb.AlarmRequest_ACTIVATE:
+		m := a.s.alarmStore.Activate(types.ID(ar.MemberID), ar.Alarm)
+		if m == nil {
+			break
+		}
+		resp.Alarms = append(resp.Alarms, m)
+		activated := oldCount == 0 && len(a.s.alarmStore.Get(m.Alarm)) == 1
+		if !activated {
+			break
+		}
+
+		if lg != nil {
+			lg.Warn("alarm raised", zap.String("alarm", m.Alarm.String()), zap.String("from", types.ID(m.MemberID).String()))
+		} else {
+			plog.Warningf("alarm %v raised by peer %s", m.Alarm, types.ID(m.MemberID))
+		}
+		switch m.Alarm {
+		case pb.AlarmType_CORRUPT:
+			a.s.applyV3 = newApplierV3Corrupt(a)
+		case pb.AlarmType_NOSPACE:
+			a.s.applyV3 = newApplierV3Capped(a)
+		default:
+			if lg != nil {
+				lg.Warn("unimplemented alarm activation", zap.String("alarm", fmt.Sprintf("%+v", m)))
+			} else {
+				plog.Errorf("unimplemented alarm activation (%+v)", m)
+			}
+		}
+	case pb.AlarmRequest_DEACTIVATE:
+		m := a.s.alarmStore.Deactivate(types.ID(ar.MemberID), ar.Alarm)
+		if m == nil {
+			break
+		}
+		resp.Alarms = append(resp.Alarms, m)
+		deactivated := oldCount > 0 && len(a.s.alarmStore.Get(ar.Alarm)) == 0
+		if !deactivated {
+			break
+		}
+
+		switch m.Alarm {
+		case pb.AlarmType_NOSPACE, pb.AlarmType_CORRUPT:
+			// TODO: check kv hash before deactivating CORRUPT?
+			if lg != nil {
+				lg.Warn("alarm disarmed", zap.String("alarm", m.Alarm.String()), zap.String("from", types.ID(m.MemberID).String()))
+			} else {
+				plog.Infof("alarm disarmed %+v", ar)
+			}
+			a.s.applyV3 = a.s.newApplierV3()
+		default:
+			if lg != nil {
+				lg.Warn("unimplemented alarm deactivation", zap.String("alarm", fmt.Sprintf("%+v", m)))
+			} else {
+				plog.Errorf("unimplemented alarm deactivation (%+v)", m)
+			}
+		}
+	default:
+		return nil, nil
+	}
+	return resp, nil
+}
+
+type applierV3Capped struct {
+	applierV3
+	q backendQuota
+}
+
+// newApplierV3Capped creates an applyV3 that will reject Puts and transactions
+// with Puts so that the number of keys in the store is capped.
+func newApplierV3Capped(base applierV3) applierV3 { return &applierV3Capped{applierV3: base} }
+
+func (a *applierV3Capped) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error) {
+	return nil, ErrNoSpace
+}
+
+func (a *applierV3Capped) Txn(r *pb.TxnRequest) (*pb.TxnResponse, error) {
+	if a.q.Cost(r) > 0 {
+		return nil, ErrNoSpace
+	}
+	return a.applierV3.Txn(r)
+}
+
+func (a *applierV3Capped) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	return nil, ErrNoSpace
+}
+
+func (a *applierV3backend) AuthEnable() (*pb.AuthEnableResponse, error) {
+	err := a.s.AuthStore().AuthEnable()
+	if err != nil {
+		return nil, err
+	}
+	return &pb.AuthEnableResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) AuthDisable() (*pb.AuthDisableResponse, error) {
+	a.s.AuthStore().AuthDisable()
+	return &pb.AuthDisableResponse{Header: newHeader(a.s)}, nil
+}
+
+func (a *applierV3backend) Authenticate(r *pb.InternalAuthenticateRequest) (*pb.AuthenticateResponse, error) {
+	ctx := context.WithValue(context.WithValue(a.s.ctx, auth.AuthenticateParamIndex{}, a.s.consistIndex.ConsistentIndex()), auth.AuthenticateParamSimpleTokenPrefix{}, r.SimpleToken)
+	resp, err := a.s.AuthStore().Authenticate(ctx, r.Name, r.Password)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserAdd(r *pb.AuthUserAddRequest) (*pb.AuthUserAddResponse, error) {
+	resp, err := a.s.AuthStore().UserAdd(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserDelete(r *pb.AuthUserDeleteRequest) (*pb.AuthUserDeleteResponse, error) {
+	resp, err := a.s.AuthStore().UserDelete(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserChangePassword(r *pb.AuthUserChangePasswordRequest) (*pb.AuthUserChangePasswordResponse, error) {
+	resp, err := a.s.AuthStore().UserChangePassword(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserGrantRole(r *pb.AuthUserGrantRoleRequest) (*pb.AuthUserGrantRoleResponse, error) {
+	resp, err := a.s.AuthStore().UserGrantRole(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserGet(r *pb.AuthUserGetRequest) (*pb.AuthUserGetResponse, error) {
+	resp, err := a.s.AuthStore().UserGet(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserRevokeRole(r *pb.AuthUserRevokeRoleRequest) (*pb.AuthUserRevokeRoleResponse, error) {
+	resp, err := a.s.AuthStore().UserRevokeRole(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleAdd(r *pb.AuthRoleAddRequest) (*pb.AuthRoleAddResponse, error) {
+	resp, err := a.s.AuthStore().RoleAdd(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleGrantPermission(r *pb.AuthRoleGrantPermissionRequest) (*pb.AuthRoleGrantPermissionResponse, error) {
+	resp, err := a.s.AuthStore().RoleGrantPermission(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleGet(r *pb.AuthRoleGetRequest) (*pb.AuthRoleGetResponse, error) {
+	resp, err := a.s.AuthStore().RoleGet(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleRevokePermission(r *pb.AuthRoleRevokePermissionRequest) (*pb.AuthRoleRevokePermissionResponse, error) {
+	resp, err := a.s.AuthStore().RoleRevokePermission(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleDelete(r *pb.AuthRoleDeleteRequest) (*pb.AuthRoleDeleteResponse, error) {
+	resp, err := a.s.AuthStore().RoleDelete(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) UserList(r *pb.AuthUserListRequest) (*pb.AuthUserListResponse, error) {
+	resp, err := a.s.AuthStore().UserList(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+func (a *applierV3backend) RoleList(r *pb.AuthRoleListRequest) (*pb.AuthRoleListResponse, error) {
+	resp, err := a.s.AuthStore().RoleList(r)
+	if resp != nil {
+		resp.Header = newHeader(a.s)
+	}
+	return resp, err
+}
+
+type quotaApplierV3 struct {
+	applierV3
+	q Quota
+}
+
+func newQuotaApplierV3(s *EtcdServer, app applierV3) applierV3 {
+	return &quotaApplierV3{app, NewBackendQuota(s, "v3-applier")}
+}
+
+func (a *quotaApplierV3) Put(txn mvcc.TxnWrite, p *pb.PutRequest) (*pb.PutResponse, error) {
+	ok := a.q.Available(p)
+	resp, err := a.applierV3.Put(txn, p)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+func (a *quotaApplierV3) Txn(rt *pb.TxnRequest) (*pb.TxnResponse, error) {
+	ok := a.q.Available(rt)
+	resp, err := a.applierV3.Txn(rt)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+func (a *quotaApplierV3) LeaseGrant(lc *pb.LeaseGrantRequest) (*pb.LeaseGrantResponse, error) {
+	ok := a.q.Available(lc)
+	resp, err := a.applierV3.LeaseGrant(lc)
+	if err == nil && !ok {
+		err = ErrNoSpace
+	}
+	return resp, err
+}
+
+type kvSort struct{ kvs []mvccpb.KeyValue }
+
+func (s *kvSort) Swap(i, j int) {
+	t := s.kvs[i]
+	s.kvs[i] = s.kvs[j]
+	s.kvs[j] = t
+}
+func (s *kvSort) Len() int { return len(s.kvs) }
+
+type kvSortByKey struct{ *kvSort }
+
+func (s *kvSortByKey) Less(i, j int) bool {
+	return bytes.Compare(s.kvs[i].Key, s.kvs[j].Key) < 0
+}
+
+type kvSortByVersion struct{ *kvSort }
+
+func (s *kvSortByVersion) Less(i, j int) bool {
+	return (s.kvs[i].Version - s.kvs[j].Version) < 0
+}
+
+type kvSortByCreate struct{ *kvSort }
+
+func (s *kvSortByCreate) Less(i, j int) bool {
+	return (s.kvs[i].CreateRevision - s.kvs[j].CreateRevision) < 0
+}
+
+type kvSortByMod struct{ *kvSort }
+
+func (s *kvSortByMod) Less(i, j int) bool {
+	return (s.kvs[i].ModRevision - s.kvs[j].ModRevision) < 0
+}
+
+type kvSortByValue struct{ *kvSort }
+
+func (s *kvSortByValue) Less(i, j int) bool {
+	return bytes.Compare(s.kvs[i].Value, s.kvs[j].Value) < 0
+}
+
+func checkRequests(rv mvcc.ReadView, rt *pb.TxnRequest, txnPath []bool, f checkReqFunc) (int, error) {
+	txnCount := 0
+	reqs := rt.Success
+	if !txnPath[0] {
+		reqs = rt.Failure
+	}
+	for _, req := range reqs {
+		if tv, ok := req.Request.(*pb.RequestOp_RequestTxn); ok && tv.RequestTxn != nil {
+			txns, err := checkRequests(rv, tv.RequestTxn, txnPath[1:], f)
+			if err != nil {
+				return 0, err
+			}
+			txnCount += txns + 1
+			txnPath = txnPath[txns+1:]
+			continue
+		}
+		if err := f(rv, req); err != nil {
+			return 0, err
+		}
+	}
+	return txnCount, nil
+}
+
+func (a *applierV3backend) checkRequestPut(rv mvcc.ReadView, reqOp *pb.RequestOp) error {
+	tv, ok := reqOp.Request.(*pb.RequestOp_RequestPut)
+	if !ok || tv.RequestPut == nil {
+		return nil
+	}
+	req := tv.RequestPut
+	if req.IgnoreValue || req.IgnoreLease {
+		// expects previous key-value, error if not exist
+		rr, err := rv.Range(req.Key, nil, mvcc.RangeOptions{})
+		if err != nil {
+			return err
+		}
+		if rr == nil || len(rr.KVs) == 0 {
+			return ErrKeyNotFound
+		}
+	}
+	if lease.LeaseID(req.Lease) != lease.NoLease {
+		if l := a.s.lessor.Lookup(lease.LeaseID(req.Lease)); l == nil {
+			return lease.ErrLeaseNotFound
+		}
+	}
+	return nil
+}
+
+func (a *applierV3backend) checkRequestRange(rv mvcc.ReadView, reqOp *pb.RequestOp) error {
+	tv, ok := reqOp.Request.(*pb.RequestOp_RequestRange)
+	if !ok || tv.RequestRange == nil {
+		return nil
+	}
+	req := tv.RequestRange
+	switch {
+	case req.Revision == 0:
+		return nil
+	case req.Revision > rv.Rev():
+		return mvcc.ErrFutureRev
+	case req.Revision < rv.FirstRev():
+		return mvcc.ErrCompacted
+	}
+	return nil
+}
+
+func compareInt64(a, b int64) int {
+	switch {
+	case a < b:
+		return -1
+	case a > b:
+		return 1
+	default:
+		return 0
+	}
+}
+
+// mkGteRange determines if the range end is a >= range. This works around grpc
+// sending empty byte strings as nil; >= is encoded in the range end as '\0'.
+// If it is a GTE range, then []byte{} is returned to indicate the empty byte
+// string (vs nil being no byte string).
+func mkGteRange(rangeEnd []byte) []byte {
+	if len(rangeEnd) == 1 && rangeEnd[0] == 0 {
+		return []byte{}
+	}
+	return rangeEnd
+}
+
+func noSideEffect(r *pb.InternalRaftRequest) bool {
+	return r.Range != nil || r.AuthUserGet != nil || r.AuthRoleGet != nil
+}
+
+func removeNeedlessRangeReqs(txn *pb.TxnRequest) {
+	f := func(ops []*pb.RequestOp) []*pb.RequestOp {
+		j := 0
+		for i := 0; i < len(ops); i++ {
+			if _, ok := ops[i].Request.(*pb.RequestOp_RequestRange); ok {
+				continue
+			}
+			ops[j] = ops[i]
+			j++
+		}
+
+		return ops[:j]
+	}
+
+	txn.Success = f(txn.Success)
+	txn.Failure = f(txn.Failure)
+}
+
+func pruneKVs(rr *mvcc.RangeResult, isPrunable func(*mvccpb.KeyValue) bool) {
+	j := 0
+	for i := range rr.KVs {
+		rr.KVs[j] = rr.KVs[i]
+		if !isPrunable(&rr.KVs[i]) {
+			j++
+		}
+	}
+	rr.KVs = rr.KVs[:j]
+}
+
+func newHeader(s *EtcdServer) *pb.ResponseHeader {
+	return &pb.ResponseHeader{
+		ClusterId: uint64(s.Cluster().ID()),
+		MemberId:  uint64(s.ID()),
+		Revision:  s.KV().Rev(),
+		RaftTerm:  s.Term(),
+	}
+}