add observe

Signed-off-by: jyz0309 <45495947@qq.com>

domain/infosync/info.go

@@ -343,9 +343,10 @@ func doRequest(ctx context.Context, addrs []string, route, method string, body i
 		if body != nil {
 			req.Header.Set("Content-Type", "application/json")
 		}
-
+		start := time.Now()
 		res, err = doRequestWithFailpoint(req)
 		if err == nil {
+			metrics.PDApiExecutionHistogram.WithLabelValues("placement").Observe(time.Since(start).Seconds())
 			bodyBytes, err := io.ReadAll(res.Body)
 			if err != nil {
 				return nil, err

metrics/server.go

@@ -230,14 +230,14 @@ var (
 			Help:      "Counter of TiFlash queries.",
 		}, []string{LblType, LblResult})
 
-	PDApiExecutionHistogram = prometheus.NewHistogram(
+	PDApiExecutionHistogram = prometheus.NewHistogramVec(
 		prometheus.HistogramOpts{
 			Namespace: "tidb",
 			Subsystem: "server",
 			Name:      "pd_api_execution_duration_seconds",
 			Help:      "Bucketed histogram of all pd api execution time (s)",
 			Buckets:   prometheus.ExponentialBuckets(0.001, 2, 20), // 1ms ~ 524s
-		})
+		}, []string{LblType})
 )
 
 // ExecuteErrorToLabel converts an execute error to label.

store/helper/helper.go

@@ -773,7 +773,7 @@ func (h *Helper) requestPD(method, uri string, body io.Reader, res interface{})
 	if err != nil {
 		return errors.Trace(err)
 	}
-	metrics.PDApiExecutionHistogram.Observe(time.Since(start).Seconds())
+	metrics.PDApiExecutionHistogram.WithLabelValues("common").Observe(time.Since(start).Seconds())
 
 	defer func() {
 		err = resp.Body.Close()