diff --git a/cpp/conf/server_config.yaml b/cpp/conf/server_config.yaml
index 717e9b10cb..40ee6f2efa 100644
--- a/cpp/conf/server_config.yaml
+++ b/cpp/conf/server_config.yaml
@@ -12,7 +12,7 @@ db_config:
   index_building_threshold: 1024          #build index file when raw data file size larger than this value, unit: MB
 
 metric_config:
-  is_startup: true # true is on, false is off
+  is_startup: off # on is activated, otherwise is down. note: case sensitive
   collector: prometheus # prometheus, now we only have prometheus
   prometheus_config:
     collect_type: pull # pull means prometheus pull the message from server, push means server push metric to push gateway
diff --git a/cpp/src/metrics/PrometheusMetrics.cpp b/cpp/src/metrics/PrometheusMetrics.cpp
index 07e1d2ee71..d0d50800ad 100644
--- a/cpp/src/metrics/PrometheusMetrics.cpp
+++ b/cpp/src/metrics/PrometheusMetrics.cpp
@@ -17,7 +17,8 @@ ServerError
 PrometheusMetrics::Init() {
     try {
         ConfigNode &configNode = ServerConfig::GetInstance().GetConfig(CONFIG_METRIC);
-        startup_ = configNode.GetValue(CONFIG_METRIC_IS_STARTUP) == "true" ? true : false;
+        startup_ = configNode.GetValue(CONFIG_METRIC_IS_STARTUP) == "on";
+        if(!startup_) return SERVER_SUCCESS;
         // Following should be read from config file.
         const std::string bind_address = configNode.GetChild(CONFIG_PROMETHEUS).GetValue(CONFIG_METRIC_PROMETHEUS_PORT);
         const std::string uri = std::string("/metrics");
diff --git a/cpp/unittest/metrics/metrics_test.cpp b/cpp/unittest/metrics/metrics_test.cpp
index 00075fbb5f..72596dc79e 100644
--- a/cpp/unittest/metrics/metrics_test.cpp
+++ b/cpp/unittest/metrics/metrics_test.cpp
@@ -102,7 +102,7 @@ TEST_F(DBTest, Metric_Tes) {
         }
     });
 
-    int loop = 10;
+    int loop = 10000;
 
     for (auto i=0; i<loop; ++i) {
         if (i==40) {