diff --git a/vendor/github.com/hashicorp/yamux/session.go b/vendor/github.com/hashicorp/yamux/session.go
index e17981839..d8446fa65 100644
--- a/vendor/github.com/hashicorp/yamux/session.go
+++ b/vendor/github.com/hashicorp/yamux/session.go
@@ -123,6 +123,12 @@ func (s *Session) IsClosed() bool {
 	}
 }
 
+// CloseChan returns a read-only channel which is closed as
+// soon as the session is closed.
+func (s *Session) CloseChan() <-chan struct{} {
+	return s.shutdownCh
+}
+
 // NumStreams returns the number of currently open streams
 func (s *Session) NumStreams() int {
 	s.streamLock.Lock()
@@ -323,8 +329,17 @@ func (s *Session) waitForSend(hdr header, body io.Reader) error {
 // potential shutdown. Since there's the expectation that sends can happen
 // in a timely manner, we enforce the connection write timeout here.
 func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
+	t := timerPool.Get()
+	timer := t.(*time.Timer)
+	timer.Reset(s.config.ConnectionWriteTimeout)
+	defer func() {
+		timer.Stop()
+		select {
+		case <-timer.C:
+		default:
+		}
+		timerPool.Put(t)
+	}()
 
 	ready := sendReady{Hdr: hdr, Body: body, Err: errCh}
 	select {
@@ -349,8 +364,17 @@ func (s *Session) waitForSendErr(hdr header, body io.Reader, errCh chan error) e
 // the send happens right here, we enforce the connection write timeout if we
 // can't queue the header to be sent.
 func (s *Session) sendNoWait(hdr header) error {
-	timer := time.NewTimer(s.config.ConnectionWriteTimeout)
-	defer timer.Stop()
+	t := timerPool.Get()
+	timer := t.(*time.Timer)
+	timer.Reset(s.config.ConnectionWriteTimeout)
+	defer func() {
+		timer.Stop()
+		select {
+		case <-timer.C:
+		default:
+		}
+		timerPool.Put(t)
+	}()
 
 	select {
 	case s.sendCh <- sendReady{Hdr: hdr}:
@@ -408,11 +432,20 @@ func (s *Session) recv() {
 	}
 }
 
+// Ensure that the index of the handler (typeData/typeWindowUpdate/etc) matches the message type
+var (
+	handlers = []func(*Session, header) error{
+		typeData:         (*Session).handleStreamMessage,
+		typeWindowUpdate: (*Session).handleStreamMessage,
+		typePing:         (*Session).handlePing,
+		typeGoAway:       (*Session).handleGoAway,
+	}
+)
+
 // recvLoop continues to receive data until a fatal error is encountered
 func (s *Session) recvLoop() error {
 	defer close(s.recvDoneCh)
 	hdr := header(make([]byte, headerSize))
-	var handler func(header) error
 	for {
 		// Read the header
 		if _, err := io.ReadFull(s.bufRead, hdr); err != nil {
@@ -428,22 +461,12 @@ func (s *Session) recvLoop() error {
 			return ErrInvalidVersion
 		}
 
-		// Switch on the type
-		switch hdr.MsgType() {
-		case typeData:
-			handler = s.handleStreamMessage
-		case typeWindowUpdate:
-			handler = s.handleStreamMessage
-		case typeGoAway:
-			handler = s.handleGoAway
-		case typePing:
-			handler = s.handlePing
-		default:
+		mt := hdr.MsgType()
+		if mt < typeData || mt > typeGoAway {
 			return ErrInvalidMsgType
 		}
 
-		// Invoke the handler
-		if err := handler(hdr); err != nil {
+		if err := handlers[mt](s, hdr); err != nil {
 			return err
 		}
 	}
diff --git a/vendor/github.com/hashicorp/yamux/stream.go b/vendor/github.com/hashicorp/yamux/stream.go
index d216e281c..aa2391973 100644
--- a/vendor/github.com/hashicorp/yamux/stream.go
+++ b/vendor/github.com/hashicorp/yamux/stream.go
@@ -47,8 +47,8 @@ type Stream struct {
 	recvNotifyCh chan struct{}
 	sendNotifyCh chan struct{}
 
-	readDeadline  time.Time
-	writeDeadline time.Time
+	readDeadline  atomic.Value // time.Time
+	writeDeadline atomic.Value // time.Time
 }
 
 // newStream is used to construct a new stream within
@@ -67,6 +67,8 @@ func newStream(session *Session, id uint32, state streamState) *Stream {
 		recvNotifyCh: make(chan struct{}, 1),
 		sendNotifyCh: make(chan struct{}, 1),
 	}
+	s.readDeadline.Store(time.Time{})
+	s.writeDeadline.Store(time.Time{})
 	return s
 }
 
@@ -122,8 +124,9 @@ START:
 WAIT:
 	var timeout <-chan time.Time
 	var timer *time.Timer
-	if !s.readDeadline.IsZero() {
-		delay := s.readDeadline.Sub(time.Now())
+	readDeadline := s.readDeadline.Load().(time.Time)
+	if !readDeadline.IsZero() {
+		delay := readDeadline.Sub(time.Now())
 		timer = time.NewTimer(delay)
 		timeout = timer.C
 	}
@@ -188,7 +191,7 @@ START:
 
 	// Send the header
 	s.sendHdr.encode(typeData, flags, s.id, max)
-	if err := s.session.waitForSendErr(s.sendHdr, body, s.sendErr); err != nil {
+	if err = s.session.waitForSendErr(s.sendHdr, body, s.sendErr); err != nil {
 		return 0, err
 	}
 
@@ -200,8 +203,9 @@ START:
 
 WAIT:
 	var timeout <-chan time.Time
-	if !s.writeDeadline.IsZero() {
-		delay := s.writeDeadline.Sub(time.Now())
+	writeDeadline := s.writeDeadline.Load().(time.Time)
+	if !writeDeadline.IsZero() {
+		delay := writeDeadline.Sub(time.Now())
 		timeout = time.After(delay)
 	}
 	select {
@@ -238,18 +242,25 @@ func (s *Stream) sendWindowUpdate() error {
 
 	// Determine the delta update
 	max := s.session.config.MaxStreamWindowSize
-	delta := max - atomic.LoadUint32(&s.recvWindow)
+	var bufLen uint32
+	s.recvLock.Lock()
+	if s.recvBuf != nil {
+		bufLen = uint32(s.recvBuf.Len())
+	}
+	delta := (max - bufLen) - s.recvWindow
 
 	// Determine the flags if any
 	flags := s.sendFlags()
 
 	// Check if we can omit the update
 	if delta < (max/2) && flags == 0 {
+		s.recvLock.Unlock()
 		return nil
 	}
 
 	// Update our window
-	atomic.AddUint32(&s.recvWindow, delta)
+	s.recvWindow += delta
+	s.recvLock.Unlock()
 
 	// Send the header
 	s.controlHdr.encode(typeWindowUpdate, flags, s.id, delta)
@@ -392,16 +403,18 @@ func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
 	if length == 0 {
 		return nil
 	}
-	if remain := atomic.LoadUint32(&s.recvWindow); length > remain {
-		s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, remain, length)
-		return ErrRecvWindowExceeded
-	}
 
 	// Wrap in a limited reader
 	conn = &io.LimitedReader{R: conn, N: int64(length)}
 
 	// Copy into buffer
 	s.recvLock.Lock()
+
+	if length > s.recvWindow {
+		s.session.logger.Printf("[ERR] yamux: receive window exceeded (stream: %d, remain: %d, recv: %d)", s.id, s.recvWindow, length)
+		return ErrRecvWindowExceeded
+	}
+
 	if s.recvBuf == nil {
 		// Allocate the receive buffer just-in-time to fit the full data frame.
 		// This way we can read in the whole packet without further allocations.
@@ -414,7 +427,7 @@ func (s *Stream) readData(hdr header, flags uint16, conn io.Reader) error {
 	}
 
 	// Decrement the receive window
-	atomic.AddUint32(&s.recvWindow, ^uint32(length-1))
+	s.recvWindow -= length
 	s.recvLock.Unlock()
 
 	// Unblock any readers
@@ -435,13 +448,13 @@ func (s *Stream) SetDeadline(t time.Time) error {
 
 // SetReadDeadline sets the deadline for future Read calls.
 func (s *Stream) SetReadDeadline(t time.Time) error {
-	s.readDeadline = t
+	s.readDeadline.Store(t)
 	return nil
 }
 
 // SetWriteDeadline sets the deadline for future Write calls
 func (s *Stream) SetWriteDeadline(t time.Time) error {
-	s.writeDeadline = t
+	s.writeDeadline.Store(t)
 	return nil
 }
 
diff --git a/vendor/github.com/hashicorp/yamux/util.go b/vendor/github.com/hashicorp/yamux/util.go
index 5fe45afcd..8a73e9249 100644
--- a/vendor/github.com/hashicorp/yamux/util.go
+++ b/vendor/github.com/hashicorp/yamux/util.go
@@ -1,5 +1,20 @@
 package yamux
 
+import (
+	"sync"
+	"time"
+)
+
+var (
+	timerPool = &sync.Pool{
+		New: func() interface{} {
+			timer := time.NewTimer(time.Hour * 1e6)
+			timer.Stop()
+			return timer
+		},
+	}
+)
+
 // asyncSendErr is used to try an async send of an error
 func asyncSendErr(ch chan error, err error) {
 	if ch == nil {
diff --git a/vendor/vendor.json b/vendor/vendor.json
index 42e31687b..f4cf94085 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -72,7 +72,7 @@
 		{"path":"github.com/hashicorp/raft-boltdb","checksumSHA1":"QAxukkv54/iIvLfsUP6IK4R0m/A=","revision":"d1e82c1ec3f15ee991f7cc7ffd5b67ff6f5bbaee","revisionTime":"2015-02-01T20:08:39Z"},
 		{"path":"github.com/hashicorp/serf/coordinate","checksumSHA1":"0PeWsO2aI+2PgVYlYlDPKfzCLEQ=","comment":"v0.7.0-66-g6c4672d","revision":"b6017ae61f4420ed0c02d5eeeb9ff3fc02953f14","revisionTime":"2018-01-19T22:43:00Z"},
 		{"path":"github.com/hashicorp/serf/serf","checksumSHA1":"QGImnWfhk0ILLZszcf3vRs/Ft7g=","comment":"v0.7.0-66-g6c4672d","revision":"b6017ae61f4420ed0c02d5eeeb9ff3fc02953f14","revisionTime":"2018-01-19T22:43:00Z"},
-		{"path":"github.com/hashicorp/yamux","checksumSHA1":"ZhK6IO2XN81Y+3RAjTcVm1Ic7oU=","revision":"d1caa6c97c9fc1cc9e83bbe34d0603f9ff0ce8bd","revisionTime":"2016-07-20T23:31:40Z"},
+		{"path":"github.com/hashicorp/yamux","checksumSHA1":"NnWv17i1tpvBNJtpdRRWpE6j4LY=","revision":"2658be15c5f05e76244154714161f17e3e77de2e","revisionTime":"2018-03-14T20:07:45Z"},
 		{"path":"github.com/mattn/go-isatty","checksumSHA1":"xZuhljnmBysJPta/lMyYmJdujCg=","revision":"66b8e73f3f5cda9f96b69efd03dd3d7fc4a5cdb8","revisionTime":"2016-08-06T12:27:52Z"},
 		{"path":"github.com/miekg/dns","checksumSHA1":"Jo+pItYOocIRdoFL0fc4nHhUEJY=","revision":"bbca4873b326f5dc54bfe31148446d4ed79a5a02","revisionTime":"2017-08-08T22:19:10Z"},
 		{"path":"github.com/mitchellh/cli","checksumSHA1":"GzfpPGtV2UJH9hFsKwzGjKrhp/A=","revision":"dff723fff508858a44c1f4bd0911f00d73b0202f","revisionTime":"2017-09-05T22:10:09Z"},