diff --git a/vendor/go.etcd.io/etcd/raft/raft.go b/vendor/go.etcd.io/etcd/raft/raft.go
index 01e23ec..cdcb43d 100644
--- a/vendor/go.etcd.io/etcd/raft/raft.go
+++ b/vendor/go.etcd.io/etcd/raft/raft.go
@@ -20,6 +20,7 @@
 	"fmt"
 	"math"
 	"math/rand"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -263,7 +264,8 @@
 
 	maxMsgSize         uint64
 	maxUncommittedSize uint64
-	prs                tracker.ProgressTracker
+	// TODO(tbg): rename to trk.
+	prs tracker.ProgressTracker
 
 	state StateType
 
@@ -327,18 +329,18 @@
 	if err != nil {
 		panic(err) // TODO(bdarnell)
 	}
-	peers := c.peers
-	learners := c.learners
-	if len(cs.Nodes) > 0 || len(cs.Learners) > 0 {
-		if len(peers) > 0 || len(learners) > 0 {
+
+	if len(c.peers) > 0 || len(c.learners) > 0 {
+		if len(cs.Voters) > 0 || len(cs.Learners) > 0 {
 			// TODO(bdarnell): the peers argument is always nil except in
 			// tests; the argument should be removed and these tests should be
 			// updated to specify their nodes through a snapshot.
-			panic("cannot specify both newRaft(peers, learners) and ConfState.(Nodes, Learners)")
+			panic("cannot specify both newRaft(peers, learners) and ConfState.(Voters, Learners)")
 		}
-		peers = cs.Nodes
-		learners = cs.Learners
+		cs.Voters = c.peers
+		cs.Learners = c.learners
 	}
+
 	r := &raft{
 		id:                        c.ID,
 		lead:                      None,
@@ -355,16 +357,17 @@
 		readOnly:                  newReadOnly(c.ReadOnlyOption),
 		disableProposalForwarding: c.DisableProposalForwarding,
 	}
-	for _, p := range peers {
-		// Add node to active config.
-		r.applyConfChange(pb.ConfChange{Type: pb.ConfChangeAddNode, NodeID: p})
-	}
-	for _, p := range learners {
-		// Add learner to active config.
-		r.applyConfChange(pb.ConfChange{Type: pb.ConfChangeAddLearnerNode, NodeID: p})
-	}
 
-	if !isHardStateEqual(hs, emptyState) {
+	cfg, prs, err := confchange.Restore(confchange.Changer{
+		Tracker:   r.prs,
+		LastIndex: raftlog.lastIndex(),
+	}, cs)
+	if err != nil {
+		panic(err)
+	}
+	assertConfStatesEquivalent(r.logger, cs, r.switchToConfig(cfg, prs))
+
+	if !IsEmptyHardState(hs) {
 		r.loadState(hs)
 	}
 	if c.Applied > 0 {
@@ -527,7 +530,6 @@
 		if id == r.id {
 			return
 		}
-
 		r.sendAppend(id)
 	})
 }
@@ -551,6 +553,46 @@
 	})
 }
 
+func (r *raft) advance(rd Ready) {
+	// If entries were applied (or a snapshot), update our cursor for
+	// the next Ready. Note that if the current HardState contains a
+	// new Commit index, this does not mean that we're also applying
+	// all of the new entries due to commit pagination by size.
+	if index := rd.appliedCursor(); index > 0 {
+		r.raftLog.appliedTo(index)
+		if r.prs.Config.AutoLeave && index >= r.pendingConfIndex && r.state == StateLeader {
+			// If the current (and most recent, at least for this leader's term)
+			// configuration should be auto-left, initiate that now.
+			ccdata, err := (&pb.ConfChangeV2{}).Marshal()
+			if err != nil {
+				panic(err)
+			}
+			ent := pb.Entry{
+				Type: pb.EntryConfChangeV2,
+				Data: ccdata,
+			}
+			if !r.appendEntry(ent) {
+				// If we could not append the entry, bump the pending conf index
+				// so that we'll try again later.
+				//
+				// TODO(tbg): test this case.
+				r.pendingConfIndex = r.raftLog.lastIndex()
+			} else {
+				r.logger.Infof("initiating automatic transition out of joint configuration %s", r.prs.Config)
+			}
+		}
+	}
+	r.reduceUncommittedSize(rd.CommittedEntries)
+
+	if len(rd.Entries) > 0 {
+		e := rd.Entries[len(rd.Entries)-1]
+		r.raftLog.stableTo(e.Index, e.Term)
+	}
+	if !IsEmptySnap(rd.Snapshot) {
+		r.raftLog.stableSnapTo(rd.Snapshot.Metadata.Index)
+	}
+}
+
 // maybeCommit attempts to advance the commit index. Returns true if
 // the commit index changed (in which case the caller should call
 // r.bcastAppend).
@@ -753,7 +795,16 @@
 		}
 		return
 	}
-	for id := range r.prs.Voters.IDs() {
+	var ids []uint64
+	{
+		idMap := r.prs.Voters.IDs()
+		ids = make([]uint64, 0, len(idMap))
+		for id := range idMap {
+			ids = append(ids, id)
+		}
+		sort.Slice(ids, func(i, j int) bool { return ids[i] < ids[j] })
+	}
+	for _, id := range ids {
 		if id == r.id {
 			continue
 		}
@@ -880,12 +931,6 @@
 		}
 
 	case pb.MsgVote, pb.MsgPreVote:
-		if r.isLearner {
-			// TODO: learner may need to vote, in case of node down when confchange.
-			r.logger.Infof("%x [logterm: %d, index: %d, vote: %x] ignored %s from %x [logterm: %d, index: %d] at term %d: learner can not vote",
-				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.Type, m.From, m.LogTerm, m.Index, r.Term)
-			return nil
-		}
 		// We can vote if this is a repeat of a vote we've already cast...
 		canVote := r.Vote == m.From ||
 			// ...we haven't voted and we don't think there's a leader yet in this term...
@@ -894,6 +939,24 @@
 			(m.Type == pb.MsgPreVote && m.Term > r.Term)
 		// ...and we believe the candidate is up to date.
 		if canVote && r.raftLog.isUpToDate(m.Index, m.LogTerm) {
+			// Note: it turns out that that learners must be allowed to cast votes.
+			// This seems counter- intuitive but is necessary in the situation in which
+			// a learner has been promoted (i.e. is now a voter) but has not learned
+			// about this yet.
+			// For example, consider a group in which id=1 is a learner and id=2 and
+			// id=3 are voters. A configuration change promoting 1 can be committed on
+			// the quorum `{2,3}` without the config change being appended to the
+			// learner's log. If the leader (say 2) fails, there are de facto two
+			// voters remaining. Only 3 can win an election (due to its log containing
+			// all committed entries), but to do so it will need 1 to vote. But 1
+			// considers itself a learner and will continue to do so until 3 has
+			// stepped up as leader, replicates the conf change to 1, and 1 applies it.
+			// Ultimately, by receiving a request to vote, the learner realizes that
+			// the candidate believes it to be a voter, and that it should act
+			// accordingly. The candidate's config may be stale, too; but in that case
+			// it won't win the election, at least in the absence of the bug discussed
+			// in:
+			// https://github.com/etcd-io/etcd/issues/7625#issuecomment-488798263.
 			r.logger.Infof("%x [logterm: %d, index: %d, vote: %x] cast %s for %x [logterm: %d, index: %d] at term %d",
 				r.id, r.raftLog.lastTerm(), r.raftLog.lastIndex(), r.Vote, m.Type, m.From, m.LogTerm, m.Index, r.Term)
 			// When responding to Msg{Pre,}Vote messages we include the term
@@ -973,10 +1036,36 @@
 
 		for i := range m.Entries {
 			e := &m.Entries[i]
+			var cc pb.ConfChangeI
 			if e.Type == pb.EntryConfChange {
-				if r.pendingConfIndex > r.raftLog.applied {
-					r.logger.Infof("propose conf %s ignored since pending unapplied configuration [index %d, applied %d]",
-						e, r.pendingConfIndex, r.raftLog.applied)
+				var ccc pb.ConfChange
+				if err := ccc.Unmarshal(e.Data); err != nil {
+					panic(err)
+				}
+				cc = ccc
+			} else if e.Type == pb.EntryConfChangeV2 {
+				var ccc pb.ConfChangeV2
+				if err := ccc.Unmarshal(e.Data); err != nil {
+					panic(err)
+				}
+				cc = ccc
+			}
+			if cc != nil {
+				alreadyPending := r.pendingConfIndex > r.raftLog.applied
+				alreadyJoint := len(r.prs.Config.Voters[1]) > 0
+				wantsLeaveJoint := len(cc.AsV2().Changes) == 0
+
+				var refused string
+				if alreadyPending {
+					refused = fmt.Sprintf("possible unapplied conf change at index %d (applied to %d)", r.pendingConfIndex, r.raftLog.applied)
+				} else if alreadyJoint && !wantsLeaveJoint {
+					refused = "must transition out of joint config first"
+				} else if !alreadyJoint && wantsLeaveJoint {
+					refused = "not in joint state; refusing empty conf change"
+				}
+
+				if refused != "" {
+					r.logger.Infof("%x ignoring conf change %v at config %s: %s", r.id, cc, r.prs.Config, refused)
 					m.Entries[i] = pb.Entry{Type: pb.EntryNormal}
 				} else {
 					r.pendingConfIndex = r.raftLog.lastIndex() + uint64(i) + 1
@@ -1010,7 +1099,7 @@
 			case ReadOnlyLeaseBased:
 				ri := r.raftLog.committed
 				if m.From == None || m.From == r.id { // from local member
-					r.readStates = append(r.readStates, ReadState{Index: r.raftLog.committed, RequestCtx: m.Entries[0].Data})
+					r.readStates = append(r.readStates, ReadState{Index: ri, RequestCtx: m.Entries[0].Data})
 				} else {
 					r.send(pb.Message{To: m.From, Type: pb.MsgReadIndexResp, Index: ri, Entries: m.Entries})
 				}
@@ -1037,7 +1126,7 @@
 		pr.RecentActive = true
 
 		if m.Reject {
-			r.logger.Debugf("%x received msgApp rejection(lastindex: %d) from %x for index %d",
+			r.logger.Debugf("%x received MsgAppResp(MsgApp was rejected, lastindex: %d) from %x for index %d",
 				r.id, m.RejectHint, m.From, m.Index)
 			if pr.MaybeDecrTo(m.Index, m.RejectHint) {
 				r.logger.Debugf("%x decreased progress of %x to [%s]", r.id, m.From, pr)
@@ -1053,6 +1142,9 @@
 				case pr.State == tracker.StateProbe:
 					pr.BecomeReplicate()
 				case pr.State == tracker.StateSnapshot && pr.Match >= pr.PendingSnapshot:
+					// TODO(tbg): we should also enter this branch if a snapshot is
+					// received that is below pr.PendingSnapshot but which makes it
+					// possible to use the log again.
 					r.logger.Debugf("%x recovered from needing snapshot, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
 					// Transition back to replicating state via probing state
 					// (which takes the snapshot into account). If we didn't
@@ -1134,8 +1226,8 @@
 			pr.BecomeProbe()
 			r.logger.Debugf("%x snapshot failed, resumed sending replication messages to %x [%s]", r.id, m.From, pr)
 		}
-		// If snapshot finish, wait for the msgAppResp from the remote node before sending
-		// out the next msgApp.
+		// If snapshot finish, wait for the MsgAppResp from the remote node before sending
+		// out the next MsgApp.
 		// If snapshot failure, wait for a heartbeat interval before next try
 		pr.ProbeSent = true
 	case pb.MsgUnreachable:
@@ -1294,7 +1386,7 @@
 	if mlastIndex, ok := r.raftLog.maybeAppend(m.Index, m.LogTerm, m.Commit, m.Entries...); ok {
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: mlastIndex})
 	} else {
-		r.logger.Debugf("%x [logterm: %d, index: %d] rejected msgApp [logterm: %d, index: %d] from %x",
+		r.logger.Debugf("%x [logterm: %d, index: %d] rejected MsgApp [logterm: %d, index: %d] from %x",
 			r.id, r.raftLog.zeroTermOnErrCompacted(r.raftLog.term(m.Index)), m.Index, m.LogTerm, m.Index, m.From)
 		r.send(pb.Message{To: m.From, Type: pb.MsgAppResp, Index: m.Index, Reject: true, RejectHint: r.raftLog.lastIndex()})
 	}
@@ -1339,12 +1431,12 @@
 	}
 
 	// More defense-in-depth: throw away snapshot if recipient is not in the
-	// config. This shouuldn't ever happen (at the time of writing) but lots of
+	// config. This shouldn't ever happen (at the time of writing) but lots of
 	// code here and there assumes that r.id is in the progress tracker.
 	found := false
 	cs := s.Metadata.ConfState
 	for _, set := range [][]uint64{
-		cs.Nodes,
+		cs.Voters,
 		cs.Learners,
 	} {
 		for _, id := range set {
@@ -1375,12 +1467,18 @@
 
 	// Reset the configuration and add the (potentially updated) peers in anew.
 	r.prs = tracker.MakeProgressTracker(r.prs.MaxInflight)
-	for _, id := range s.Metadata.ConfState.Nodes {
-		r.applyConfChange(pb.ConfChange{NodeID: id, Type: pb.ConfChangeAddNode})
+	cfg, prs, err := confchange.Restore(confchange.Changer{
+		Tracker:   r.prs,
+		LastIndex: r.raftLog.lastIndex(),
+	}, cs)
+
+	if err != nil {
+		// This should never happen. Either there's a bug in our config change
+		// handling or the client corrupted the conf change.
+		panic(fmt.Sprintf("unable to restore config %+v: %s", cs, err))
 	}
-	for _, id := range s.Metadata.ConfState.Learners {
-		r.applyConfChange(pb.ConfChange{NodeID: id, Type: pb.ConfChangeAddLearnerNode})
-	}
+
+	assertConfStatesEquivalent(r.logger, cs, r.switchToConfig(cfg, prs))
 
 	pr := r.prs.Progress[r.id]
 	pr.MaybeUpdate(pr.Next - 1) // TODO(tbg): this is untested and likely unneeded
@@ -1397,21 +1495,40 @@
 	return pr != nil && !pr.IsLearner
 }
 
-func (r *raft) applyConfChange(cc pb.ConfChange) pb.ConfState {
-	cfg, prs, err := confchange.Changer{
-		Tracker:   r.prs,
-		LastIndex: r.raftLog.lastIndex(),
-	}.Simple(cc)
+func (r *raft) applyConfChange(cc pb.ConfChangeV2) pb.ConfState {
+	cfg, prs, err := func() (tracker.Config, tracker.ProgressMap, error) {
+		changer := confchange.Changer{
+			Tracker:   r.prs,
+			LastIndex: r.raftLog.lastIndex(),
+		}
+		if cc.LeaveJoint() {
+			return changer.LeaveJoint()
+		} else if autoLeave, ok := cc.EnterJoint(); ok {
+			return changer.EnterJoint(autoLeave, cc.Changes...)
+		}
+		return changer.Simple(cc.Changes...)
+	}()
+
 	if err != nil {
+		// TODO(tbg): return the error to the caller.
 		panic(err)
 	}
+
+	return r.switchToConfig(cfg, prs)
+}
+
+// switchToConfig reconfigures this node to use the provided configuration. It
+// updates the in-memory state and, when necessary, carries out additional
+// actions such as reacting to the removal of nodes or changed quorum
+// requirements.
+//
+// The inputs usually result from restoring a ConfState or applying a ConfChange.
+func (r *raft) switchToConfig(cfg tracker.Config, prs tracker.ProgressMap) pb.ConfState {
 	r.prs.Config = cfg
 	r.prs.Progress = prs
 
 	r.logger.Infof("%x switched to configuration %s", r.id, r.prs.Config)
-	// Now that the configuration is updated, handle any side effects.
-
-	cs := pb.ConfState{Nodes: r.prs.VoterNodes(), Learners: r.prs.LearnerNodes()}
+	cs := r.prs.ConfState()
 	pr, ok := r.prs.Progress[r.id]
 
 	// Update whether the node itself is a learner, resetting to false when the
@@ -1433,13 +1550,21 @@
 
 	// The remaining steps only make sense if this node is the leader and there
 	// are other nodes.
-	if r.state != StateLeader || len(cs.Nodes) == 0 {
+	if r.state != StateLeader || len(cs.Voters) == 0 {
 		return cs
 	}
+
 	if r.maybeCommit() {
-		// The quorum size may have been reduced (but not to zero), so see if
-		// any pending entries can be committed.
+		// If the configuration change means that more entries are committed now,
+		// broadcast/append to everyone in the updated config.
 		r.bcastAppend()
+	} else {
+		// Otherwise, still probe the newly added replicas; there's no reason to
+		// let them wait out a heartbeat interval (or the next incoming
+		// proposal).
+		r.prs.Visit(func(id uint64, pr *tracker.Progress) {
+			r.maybeSendAppend(id, false /* sendIfEmpty */)
+		})
 	}
 	// If the the leadTransferee was removed, abort the leadership transfer.
 	if _, tOK := r.prs.Progress[r.leadTransferee]; !tOK && r.leadTransferee != 0 {