fix_: status backend server websocket IO wait (#6154)

Author: qfrank

cmd/status-backend/server/server.go

@@ -53,10 +53,26 @@ func (s *Server) signalHandler(data []byte) {
 	s.lock.Lock()
 	defer s.lock.Unlock()
 
+	deleteConnection := func(connection *websocket.Conn) {
+		delete(s.connections, connection)
+		err := connection.Close()
+		if err != nil {
+			log.Error("failed to close connection", "error", err)
+		}
+	}
+
 	for connection := range s.connections {
-		err := connection.WriteMessage(websocket.TextMessage, data)
+		err := connection.SetWriteDeadline(time.Now().Add(5 * time.Second))
+		if err != nil {
+			log.Error("failed to set write deadline", "error", err)
+			deleteConnection(connection)
+			continue
+		}
+
+		err = connection.WriteMessage(websocket.TextMessage, data)
 		if err != nil {
-			log.Error("failed to write message: %w", err)
+			log.Error("failed to write signal message", "error", err)
+			deleteConnection(connection)
 		}
 	}
 }
@@ -130,6 +146,7 @@ func (s *Server) signals(w http.ResponseWriter, r *http.Request) {
 		log.Error("failed to upgrade connection: %w", err)
 		return
 	}
+	log.Debug("new websocket connection")
 
 	s.connections[connection] = struct{}{}
 }

cmd/statusd/main.go

@@ -318,7 +318,7 @@ func main() {
 
 		// Check if profiling shall be enabled.
 		if *pprofEnabled {
-			profiling.NewProfiler(*pprofPort).Go()
+			profiling.NewProfiler(fmt.Sprintf(":%d", *pprofPort)).Go()
 		}
 
 		if config.PushNotificationServerConfig.Enabled {

mobile/status.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"runtime"
 	"unsafe"
 
 	"go.uber.org/zap"
@@ -1071,6 +1072,17 @@ func writeHeapProfile(dataDir string) string { //nolint: deadcode
 	return makeJSONResponse(err)
 }
 
+// StartProfiling starts profiling and HTTP server for pprof
+func StartProfiling(address string) string {
+	return callWithResponse(startProfiling, address)
+}
+
+func startProfiling(address string) string {
+	runtime.SetMutexProfileFraction(5)
+	profiling.NewProfiler(address).Go()
+	return makeJSONResponse(nil)
+}
+
 func makeJSONResponse(err error) string {
 	errString := ""
 	if err != nil {

profiling/profiler.go

@@ -1,7 +1,6 @@
 package profiling
 
 import (
-	"fmt"
 	"net/http"
 	hpprof "net/http/pprof"
 	"time"
@@ -19,7 +18,7 @@ type Profiler struct {
 
 // NewProfiler creates an instance of the profiler with
 // the given port.
-func NewProfiler(port int) *Profiler {
+func NewProfiler(address string) *Profiler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/debug/pprof/", hpprof.Index)
 	mux.HandleFunc("/debug/pprof/cmdline", hpprof.Cmdline)
@@ -28,7 +27,7 @@ func NewProfiler(port int) *Profiler {
 	mux.HandleFunc("/debug/pprof/trace", hpprof.Trace)
 	p := Profiler{
 		server: &http.Server{
-			Addr:              fmt.Sprintf(":%d", port),
+			Addr:              address,
 			ReadHeaderTimeout: 5 * time.Second,
 			Handler:           mux,
 		},