consul: Write the byte to set the RPC mode

consul/pool.go

@@ -14,7 +14,9 @@ type Conn struct {
 
 // ConnPool is used to maintain a connection pool to other
 // Consul servers. This is used to reduce the latency of
-// RPC requests between servers
+// RPC requests between servers. It is only used to pool
+// connections in the rpcConsul mode. Raft connections
+// are pooled seperately.
 type ConnPool struct {
 	sync.Mutex
 
@@ -99,6 +101,9 @@ func (p *ConnPool) getNewConn(addr net.Addr) (*Conn, error) {
 	conn.SetKeepAlive(true)
 	conn.SetNoDelay(true)
 
+	// Write the Consul RPC byte to set the mode
+	conn.Write([]byte{byte(rpcConsul)})
+
 	// Wrap the connection
 	c := &Conn{
 		addr: addr,

consul/raft_rpc.go

@@ -74,5 +74,12 @@ func (l *RaftLayer) Addr() net.Addr {
 
 // Dial is used to create a new outgoing connection
 func (l *RaftLayer) Dial(address string, timeout time.Duration) (net.Conn, error) {
-	return net.DialTimeout("tcp", address, timeout)
+	conn, err := net.DialTimeout("tcp", address, timeout)
+	if err != nil {
+		return nil, err
+	}
+
+	// Write the Raft byte to set the mode
+	conn.Write([]byte{byte(rpcRaft)})
+	return conn, err
 }