diff --git a/config/config.production.yml b/config/config.production.yml
index 9cbdf1a..0f63a0f 100644
--- a/config/config.production.yml
+++ b/config/config.production.yml
@@ -19,10 +19,9 @@ features:
 
   metrics:
     target: gcp
-    endpoint: ":9213"
+    endpoint: ":9213" # using Custom Exporter port as default from: https://github.com/prometheus/prometheus/wiki/Default-port-allocations
     sampling_fraction: 0.0001
 
   tracing:
     target: gcp
-    endpoint: ":9213"
     sampling_fraction: 0.0001
diff --git a/config/config.yml b/config/config.yml
index 0d8d3ae..8cdcfab 100644
--- a/config/config.yml
+++ b/config/config.yml
@@ -79,6 +79,7 @@ features:
     endpoint: ":0"
     sampling_fraction: 1.0
     collect_period: 10s
+    # histogram_distribution: [.005, .01, .025, .05, .1, .25, .5, 1, 2.5, 5, 10]
   tracing:
     enabled: false
     backend: stdout
diff --git a/go.mod b/go.mod
index d521954..cf38366 100644
--- a/go.mod
+++ b/go.mod
@@ -10,6 +10,8 @@ replace github.com/xmlking/grpc-starter-kit => ./
 
 //replace github.com/xmlking/toolkit/logger => ../toolkit/logger
 
+//replace github.com/xmlking/toolkit/telemetry => ../toolkit/telemetry
+
 //replace github.com/xmlking/toolkit => github.com/xmlking/toolkit v0.1.2-0.20210125025404-51fc2d71fb2d
 
 require (
@@ -35,7 +37,7 @@ require (
 	github.com/xmlking/toolkit/broker/cloudevents v0.2.1
 	github.com/xmlking/toolkit/confy v0.2.1
 	github.com/xmlking/toolkit/logger v0.2.1
-	github.com/xmlking/toolkit/telemetry v0.2.1
+	github.com/xmlking/toolkit/telemetry v0.2.2-0.20210807070629-098bbac6595c
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.22.0
 	go.opentelemetry.io/otel v1.0.0-RC2
 	go.opentelemetry.io/otel/metric v0.22.0
diff --git a/go.sum b/go.sum
index 7a305cb..a2151ea 100644
--- a/go.sum
+++ b/go.sum
@@ -627,8 +627,8 @@ github.com/xmlking/toolkit/confy v0.2.1 h1:ibgDZRsWGSxoLBqNfGkooUszoew1QsnETuMBy
 github.com/xmlking/toolkit/confy v0.2.1/go.mod h1:+kiAzggAehxbARiXxzD0zIzYDnZW4WmI3u1mxhq5QM0=
 github.com/xmlking/toolkit/logger v0.2.1 h1:6szYX1oQEOdms6zfWe8WPKOLbZtm7Ma9pJpeBxUANIE=
 github.com/xmlking/toolkit/logger v0.2.1/go.mod h1:9I+copkbirFrYQBDsXVZ3OnrDzPHp+HWk6Y2FxfkGrA=
-github.com/xmlking/toolkit/telemetry v0.2.1 h1:oQQUk+hLPn9ewGcxM7ffJFmjwrMTKfLe4o1DTVbKzJw=
-github.com/xmlking/toolkit/telemetry v0.2.1/go.mod h1:PYbKit3k+UjvA3Qffh+KhE/0ByNS6X2dTRUU+cncNp8=
+github.com/xmlking/toolkit/telemetry v0.2.2-0.20210807070629-098bbac6595c h1:BXXtTJ1zayPbRQCasFzr+rrVZqsBw0yrjQjDtzQDOtk=
+github.com/xmlking/toolkit/telemetry v0.2.2-0.20210807070629-098bbac6595c/go.mod h1:AGWKP5cgDpEC4M/WqJDzA7IYSpAScb9PECY8bkFRj40=
 github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 github.com/yalp/jsonpath v0.0.0-20180802001716-5cc68e5049a0/go.mod h1:/LWChgwKmvncFJFHJ7Gvn9wZArjbV5/FppcK2fKk/tI=
 github.com/yudai/gojsondiff v1.0.0/go.mod h1:AY32+k2cwILAkW1fbgxQ5mUmMiZFgLIV+FBNExI05xg=
diff --git a/internal/config/schema.go b/internal/config/schema.go
index dc1545d..32a2ef1 100644
--- a/internal/config/schema.go
+++ b/internal/config/schema.go
@@ -74,25 +74,6 @@ type Features struct {
 	Translog  *Features_Translog       `yaml:"translog,omitempty"`
 }
 
-// Features_Metrics struct
-type Features_Metrics struct {
-	Enabled  bool   `yaml:",omitempty" default:"false"`
-	Backend  string `yaml:",omitempty" validate:"oneof=gcp prometheus stdout" default:"stdout"`
-	Endpoint string `yaml:"endpoint,omitempty"`
-	// SamplingFraction >= 1 will always sample. SamplingFraction < 0 are treated as zero.
-	SamplingFraction float64       `yaml:"sampling_fraction,omitempty" default:"1.0"`
-	CollectPeriod    time.Duration `yaml:"collect_period,omitempty" default:"10s"`
-}
-
-// Features_Tracing struct
-type Features_Tracing struct {
-	Enabled  bool   `yaml:",omitempty" default:"false"`
-	Backend  string `yaml:",omitempty" validate:"oneof=gcp stdout" default:"stdout"`
-	Endpoint string `yaml:"endpoint,omitempty"`
-	// SamplingFraction >= 1 will always sample. SamplingFraction < 0 are treated as zero.
-	SamplingFraction float64 `yaml:"sampling_fraction,omitempty" default:"1.0"`
-}
-
 // Features_TLS struct
 type Features_TLS struct {
 	Enabled    bool   `yaml:",omitempty" default:"false"`
diff --git a/service/play/README.md b/service/play/README.md
index d5c52f9..5dacbdf 100644
--- a/service/play/README.md
+++ b/service/play/README.md
@@ -18,6 +18,8 @@ export CONFY_FEATURES_TRACING_ENABLED=true
 # enable metrics target: `prometheus` and tracing target: `stdout`
 export CONFY_FEATURES_METRICS_TARGET=prometheus
 export CONFY_FEATURES_TRACING_TARGET=stdout
+# lock  `prometheus` exporter port
+export CONFY_FEATURES_METRICS_ENDPOINT=":9213"
 # when using with target: `gcp`
 export GOOGLE_CLOUD_PROJECT=xyz
 export GOOGLE_APPLICATION_CREDENTIALS=../../../Apps/micro-starter-kit.json