Revert "server: add version monitoring"

This reverts commit 4f1f003d04.

server/peer_server.go

@@ -6,7 +6,6 @@ import (
 	"math/rand"
 	"net/http"
 	"net/url"
-	"os"
 	"sort"
 	"strings"
 	"sync"
@@ -293,7 +292,6 @@ func (s *PeerServer) Start(snapshot bool, clusterConfig *ClusterConfig) error {
 	s.startRoutine(s.monitorTimeoutThreshold)
 	s.startRoutine(s.monitorActiveSize)
 	s.startRoutine(s.monitorPeerActivity)
-	s.startRoutine(s.monitorVersion)
 
 	// open the snapshot
 	if snapshot {
@@ -897,30 +895,3 @@ func (s *PeerServer) monitorPeerActivity() {
 		}
 	}
 }
-
-func (s *PeerServer) monitorVersion() {
-	for {
-		select {
-		case <-s.closeChan:
-			return
-		case <-time.After(time.Second):
-		}
-
-		resp, err := s.store.Get("/_etcd/next-internal-version", false, false)
-		if err != nil {
-			continue
-		}
-		// only support upgrading to etcd2
-		if *resp.Node.Value == "2" {
-			log.Infof("%s: detected next internal version 2, exit after 10 seconds.", s.config.Name)
-		} else {
-			log.Infof("%s: detected invaild next internal version %s", s.config.Name, *resp.Node.Value)
-			continue
-		}
-		time.Sleep(10 * time.Second)
-		// be nice to raft. try not to corrupt log file.
-		go s.raftServer.Stop()
-		time.Sleep(time.Second)
-		os.Exit(0)
-	}
-}