fix: start telemetry independently from the API server

CHANGELOG.md

@@ -125,6 +125,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (client) [\#737](https://github.com/line/lbm-sdk/pull/737) check multisig key list to prevent unexpected key deletion
 * (simapp) [\#752](https://github.com/line/lbm-sdk/pull/752) add x/distribution's module account into blockedAddr
 * (x/auth) [\#754](https://github.com/line/lbm-sdk/pull/754) Fix wrong sequences in `sign-batch`
+* (server) [\#763](https://github.com/line/lbm-sdk/pull/763) start telemetry independently from the API server
 
 ### Breaking Changes
 * (proto) [\#564](https://github.com/line/lbm-sdk/pull/564) change gRPC path to original cosmos path

server/api/server.go

@@ -90,16 +90,6 @@ func New(clientCtx client.Context, logger log.Logger) *Server {
 // non-blocking, so an external signal handler must be used.
 func (s *Server) Start(cfg config.Config) error {
 	s.mtx.Lock()
-	if cfg.Telemetry.Enabled {
-		m, err := telemetry.New(cfg.Telemetry)
-		if err != nil {
-			s.mtx.Unlock()
-			return err
-		}
-
-		s.metrics = m
-		s.registerMetrics()
-	}
 
 	ostCfg := ostrpcserver.DefaultConfig()
 	ostCfg.MaxOpenConnections = int(cfg.API.MaxOpenConnections)
@@ -115,18 +105,17 @@ func (s *Server) Start(cfg config.Config) error {
 	}
 
 	s.registerGRPCGatewayRoutes()
-
 	s.listener = listener
 	var h http.Handler = s.Router
 
+	s.mtx.Unlock()
+
 	if cfg.API.EnableUnsafeCORS {
 		allowAllCORS := handlers.CORS(handlers.AllowedHeaders([]string{"Content-Type"}))
-		s.mtx.Unlock()
 		return ostrpcserver.Serve(s.listener, allowAllCORS(h), s.logger, ostCfg)
 	}
 
 	s.logger.Info("starting API server...")
-	s.mtx.Unlock()
 	return ostrpcserver.Serve(s.listener, s.Router, s.logger, ostCfg)
 }
 
@@ -141,6 +130,13 @@ func (s *Server) registerGRPCGatewayRoutes() {
 	s.Router.PathPrefix("/").Handler(s.GRPCGatewayRouter)
 }
 
+func (s *Server) SetTelemetry(m *telemetry.Metrics) {
+	s.mtx.Lock()
+	s.metrics = m
+	s.registerMetrics()
+	s.mtx.Unlock()
+}
+
 func (s *Server) registerMetrics() {
 	metricsHandler := func(w http.ResponseWriter, r *http.Request) {
 		format := strings.TrimSpace(r.FormValue("format"))

server/start.go

@@ -33,6 +33,7 @@ import (
 	"github.com/line/lbm-sdk/store/cache"
 	"github.com/line/lbm-sdk/store/iavl"
 	storetypes "github.com/line/lbm-sdk/store/types"
+	"github.com/line/lbm-sdk/telemetry"
 )
 
 // Ostracon full-node start flags
@@ -200,6 +201,10 @@ func startStandAlone(ctx *Context, appCreator types.AppCreator) error {
 	}
 
 	app := appCreator(ctx.Logger, db, traceWriter, ctx.Viper)
+	_, err = startTelemetry(config.GetConfig(ctx.Viper))
+	if err != nil {
+		return err
+	}
 
 	svr, err := server.NewServer(addr, transport, app)
 	if err != nil {
@@ -319,6 +324,11 @@ func startInProcess(ctx *Context, clientCtx client.Context, appCreator types.App
 		app.RegisterTendermintService(clientCtx)
 	}
 
+	metrics, err := startTelemetry(config)
+	if err != nil {
+		return err
+	}
+
 	var apiSrv *api.Server
 	if config.API.Enable {
 		genDoc, err := genDocProvider()
@@ -330,6 +340,9 @@ func startInProcess(ctx *Context, clientCtx client.Context, appCreator types.App
 
 		apiSrv = api.New(clientCtx, ctx.Logger.With("module", "api-server"))
 		app.RegisterAPIRoutes(apiSrv, config.API)
+		if config.Telemetry.Enabled {
+			apiSrv.SetTelemetry(metrics)
+		}
 		errCh := make(chan error)
 
 		go func() {
@@ -441,3 +454,10 @@ func startInProcess(ctx *Context, clientCtx client.Context, appCreator types.App
 	// wait for signal capture and gracefully return
 	return WaitForQuitSignals()
 }
+
+func startTelemetry(cfg config.Config) (*telemetry.Metrics, error) {
+	if !cfg.Telemetry.Enabled {
+		return nil, nil
+	}
+	return telemetry.New(cfg.Telemetry)
+}