Instrument with less labels and more focused metrics

lib/instrument/prometheus.go

@@ -16,8 +16,10 @@ const (
 )
 
 type promInst struct {
-	visits *prometheus.CounterVec
+	visits    *prometheus.CounterVec
-	reqDur *prometheus.HistogramVec
+	reqDur    *prometheus.HistogramVec
+	search    *prometheus.CounterVec
+	searchDur *prometheus.GaugeVec
 }
 
 func Init() Instrument {
@@ -28,7 +30,7 @@ func Init() Instrument {
 			Name: "trantor_visits_total",
 			Help: "Number of visits.",
 		},
-		[]string{"section", "id", "search", "fmt"},
+		[]string{"section"},
 	)
 	reqDur := prometheus.NewHistogramVec(
 		prometheus.HistogramOpts{
@@ -37,13 +39,31 @@ func Init() Instrument {
 		},
 		[]string{"section"},
 	)
+	search := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "trantor_search_total",
+			Help: "Number of searches.",
+		},
+		[]string{"search"},
+	)
+	searchDur := prometheus.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "trantor_search_duration_seconds",
+			Help: "Duration of the search in seconds.",
+		},
+		[]string{"search"},
+	)
 
 	prometheus.MustRegister(visits)
 	prometheus.MustRegister(reqDur)
+	prometheus.MustRegister(search)
+	prometheus.MustRegister(searchDur)
 
 	return &promInst{
-		visits: visits,
+		visits:    visits,
-		reqDur: reqDur,
+		reqDur:    reqDur,
+		search:    search,
+		searchDur: searchDur,
 	}
 }
 
@@ -56,6 +76,8 @@ func promHandle() {
 }
 
 func (in promInst) Request(req RequestData) {
-	in.visits.WithLabelValues(req.Section, req.ID, req.Search, req.Fmt).Inc()
+	in.visits.WithLabelValues(req.Section).Inc()
 	in.reqDur.WithLabelValues(req.Section).Observe(req.Duration.Seconds())
+	in.search.WithLabelValues(req.Search).Inc()
+	in.searchDur.WithLabelValues(req.Search).Set(req.Duration.Seconds())
 }

lib/stats.go

@@ -120,11 +120,11 @@ func (sg StatsGatherer) worker() {
 		}
 
 		sg.instrument.Request(instrument.RequestData{
-			Section: section,
+			Section:  section,
-			ID: id,
+			ID:       id,
-			Search: search,
+			Search:   search,
-			Fmt: fmt,
+			Fmt:      fmt,
-			Duration: req.duration
+			Duration: req.duration,
 		})
 		switch section {
 		case "download":