servers: fixed starting/stopping of servers

server/http/server.go

@@ -35,10 +35,9 @@ func constructor(srvcfg *chihaya.ServerConfig, tkr *tracker.Tracker) (server.Ser
 }
 
 type httpServer struct {
-	cfg      *httpConfig
-	tkr      *tracker.Tracker
-	grace    *graceful.Server
-	stopping bool
+	cfg   *httpConfig
+	tkr   *tracker.Tracker
+	grace *graceful.Server
 }
 
 func (s *httpServer) Start() {
@@ -49,9 +48,8 @@ func (s *httpServer) Start() {
 			ReadTimeout:  s.cfg.ReadTimeout,
 			WriteTimeout: s.cfg.WriteTimeout,
 		},
-		Timeout:           s.cfg.RequestTimeout,
-		NoSignalHandling:  true,
-		ShutdownInitiated: func() { s.stopping = true },
+		Timeout:          s.cfg.RequestTimeout,
+		NoSignalHandling: true,
 		ConnState: func(conn net.Conn, state http.ConnState) {
 			switch state {
 			case http.StateNew:
@@ -76,7 +74,7 @@ func (s *httpServer) Start() {
 	if err := s.grace.ListenAndServe(); err != nil {
 		if opErr, ok := err.(*net.OpError); !ok || (ok && opErr.Op != "accept") {
 			log.Printf("Failed to gracefully run HTTP server: %s", err.Error())
-			return
+			panic(err)
 		}
 	}
 
@@ -84,12 +82,8 @@ func (s *httpServer) Start() {
 }
 
 func (s *httpServer) Stop() {
-	if !s.stopping {
-		s.grace.Stop(s.grace.Timeout)
-	}
-
-	s.grace = nil
-	s.stopping = false
+	s.grace.Stop(s.grace.Timeout)
+	<-s.grace.StopChan()
 }
 
 func (s *httpServer) routes() *httprouter.Router {

server/prometheus/prometheus.go

@@ -8,6 +8,8 @@ package prometheus
 
 import (
 	"errors"
+	"log"
+	"net"
 	"net/http"
 	"time"
 
@@ -80,8 +82,18 @@ func (s *Server) Start() {
 		Timeout:          s.cfg.ShutdownTimeout,
 		NoSignalHandling: true,
 	}
+
+	if err := s.grace.ListenAndServe(); err != nil {
+		if opErr, ok := err.(*net.OpError); !ok || (ok && opErr.Op != "accept") {
+			log.Printf("Failed to gracefully run Prometheus server: %s", err.Error())
+			panic(err)
+		}
+	}
+
+	log.Println("Prometheus server shut down cleanly")
 }
 
 func (s *Server) Stop() {
 	s.grace.Stop(s.cfg.ShutdownTimeout)
+	<-s.grace.StopChan()
 }

server/store/store.go

@@ -111,6 +111,9 @@ type Store struct {
 }
 
 func (s *Store) Start() {
+	<-s.shutdown
+	s.wg.Wait()
+	log.Println("Store server shut down cleanly")
 }
 
 func (s *Store) Stop() {