Fix remove member failed.

Signed-off-by: Max Neverov <neverov.max@gmail.com>

server/etcdserver/server.go

@@ -86,7 +86,7 @@ const (
 	StoreKeysPrefix    = "/1"
 
 	// HealthInterval is the minimum time the cluster should be healthy
-	// before accepting add member requests.
+	// before accepting add and delete member requests.
 	HealthInterval = 5 * time.Second
 
 	purgeFileInterval = 30 * time.Second
@@ -1592,14 +1592,13 @@ func (s *EtcdServer) mayRemoveMember(id types.ID) error {
 	}
 
 	// protect quorum if some members are down
-	m := s.cluster.VotingMembers()
-	active := numConnectedSince(s.r.transport, time.Now().Add(-HealthInterval), s.MemberID(), m)
-	if (active - 1) < 1+((len(m)-1)/2) {
+	since := time.Now().Add(-HealthInterval)
+	if !isConnectedToQuorumSince(s.r.transport, since, s.MemberID(), s.cluster.Members()) {
 		lg.Warn(
 			"rejecting member remove request; local member has not been connected to all peers, reconfigure breaks active quorum",
 			zap.String("local-member-id", s.MemberID().String()),
 			zap.String("requested-member-remove", id.String()),
-			zap.Int("active-peers", active),
+			zap.Int("active-peers", numConnectedSince(s.r.transport, since, s.MemberID(), s.cluster.Members())),
 			zap.Error(errors.ErrUnhealthy),
 		)
 		return errors.ErrUnhealthy

server/etcdserver/util.go

@@ -33,7 +33,7 @@ func isConnectedToQuorumSince(transport rafthttp.Transporter, since time.Time, s
 // remote member since the given time.
 func isConnectedSince(transport rafthttp.Transporter, since time.Time, remote types.ID) bool {
 	t := transport.ActiveSince(remote)
-	return !t.IsZero() && t.Before(since)
+	return !t.IsZero() && !t.After(since)
 }
 
 // isConnectedFullySince checks whether the local member is connected to all

tests/common/member_test.go

@@ -207,7 +207,8 @@ func TestMemberRemove(t *testing.T) {
 
 				testutils.ExecuteUntil(ctx, t, func() {
 					if quorumTc.waitForQuorum {
-						time.Sleep(etcdserver.HealthInterval)
+						// wait for health interval + leader election
+						time.Sleep(etcdserver.HealthInterval + 2*time.Second)
 					}
 
 					memberID, clusterID := memberToRemove(ctx, t, cc, c.ClusterSize)