Merge pull request #1898 from robszumski/improve-logging

Improve logging for etcdserver and rafthttp

Documentation/0.5/clustering.md

@@ -199,7 +199,7 @@ ignored on this machine.
 ```
 $ etcd -name infra0 -initial-advertise-peer-urls http://10.0.1.10:2380 \
   -discovery https://discovery.etcd.io/3e86b59982e49066c5d813af1c2e2579cbf573de
-etcdserver: warn: ignoring discovery: etcd has already been initialized and has a valid log in /var/lib/etcd
+etcdserver: discovery token ignored since a cluster has already been initialized. Valid log found at /var/lib/etcd
 ```
 
 # 0.4 to 0.5+ Migration Guide

etcdserver/server.go

@@ -264,7 +264,7 @@ func NewServer(cfg *ServerConfig) (*EtcdServer, error) {
 		id, n, s, w = startNode(cfg, cfg.Cluster.MemberIDs())
 	case haveWAL:
 		if cfg.ShouldDiscover() {
-			log.Printf("etcdserver: warn: ignoring discovery: etcd has already been initialized and has a valid log in %q", cfg.WALDir())
+			log.Printf("etcdserver: discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir())
 		}
 		var index uint64
 		snapshot, err := ss.Load()

rafthttp/streamer.go

@@ -59,7 +59,7 @@ func startStreamServer(w WriteFlusher, to types.ID, term uint64, fs *stats.Follo
 		done: make(chan struct{}),
 	}
 	go s.handle(w)
-	log.Printf("rafthttp: stream server to %s at term %d starts", to, term)
+	log.Printf("rafthttp: starting server stream to %s at term %d", to, term)
 	return s
 }
 
@@ -73,8 +73,8 @@ func (s *streamServer) send(ents []raftpb.Entry) error {
 	case s.q <- ents:
 		return nil
 	default:
-		log.Printf("rafthttp: streamer reaches maximal serving to %s", s.to)
-		return fmt.Errorf("reach maximal serving")
+		log.Printf("rafthttp: maximum number of stream buffer entries to %d has been reached", s.to)
+		return fmt.Errorf("maximum number of stream buffer entries has been reached")
 	}
 }
 
@@ -88,14 +88,14 @@ func (s *streamServer) stopNotify() <-chan struct{} { return s.done }
 func (s *streamServer) handle(w WriteFlusher) {
 	defer func() {
 		close(s.done)
-		log.Printf("rafthttp: stream server to %s at term %d is closed", s.to, s.term)
+		log.Printf("rafthttp: server streaming to %s at term %d has been stopped", s.to, s.term)
 	}()
 
 	ew := &entryWriter{w: w}
 	for ents := range s.q {
 		start := time.Now()
 		if err := ew.writeEntries(ents); err != nil {
-			log.Printf("rafthttp: write ents error: %v", err)
+			log.Printf("rafthttp: encountered error writing to server log stream: %v", err)
 			return
 		}
 		w.Flush()
@@ -149,7 +149,7 @@ func (s *streamClient) start(tr http.RoundTripper, u string, cid types.ID) error
 	}
 	s.closer = resp.Body
 	go s.handle(resp.Body)
-	log.Printf("rafthttp: stream client to %s at term %d starts", s.to, s.term)
+	log.Printf("rafthttp: starting client stream to %s at term %d", s.to, s.term)
 	return nil
 }
 
@@ -170,7 +170,7 @@ func (s *streamClient) isStopped() bool {
 func (s *streamClient) handle(r io.Reader) {
 	defer func() {
 		close(s.done)
-		log.Printf("rafthttp: stream client to %s at term %d is closed", s.to, s.term)
+		log.Printf("rafthttp: client streaming to %s at term %d has been stopped", s.to, s.term)
 	}()
 
 	er := &entryReader{r: r}
@@ -178,7 +178,7 @@ func (s *streamClient) handle(r io.Reader) {
 		ents, err := er.readEntries()
 		if err != nil {
 			if err != io.EOF {
-				log.Printf("rafthttp: read ents error: %v", err)
+				log.Printf("rafthttp: encountered error reading the client log stream: %v", err)
 			}
 			return
 		}