Fix request count metric for NGINX Plus receiver (#1096)

Author: dhurley

internal/collector/nginxplusreceiver/scraper.go

@@ -46,6 +46,7 @@ type NginxPlusScraper struct {
 	logger                        *zap.Logger
 	settings                      receiver.Settings
 	init                          sync.Once
+	previousHTTPRequestsTotal     uint64
 }
 
 type ResponseStatuses struct {
@@ -107,6 +108,8 @@ func (nps *NginxPlusScraper) Scrape(ctx context.Context) (pmetric.Metrics, error
 			nps.logger.Error("Failed to get stats from plus API", zap.Error(err))
 			return
 		}
+
+		nps.previousHTTPRequestsTotal = stats.HTTPRequests.Total
 		nps.createPreviousServerZoneResponses(stats)
 		nps.createPreviousLocationZoneResponses(stats)
 	})
@@ -194,7 +197,10 @@ func (nps *NginxPlusScraper) recordMetrics(stats *plusapi.Stats) {
 
 	// HTTP Requests
 	nps.mb.RecordNginxHTTPRequestsDataPoint(now, int64(stats.HTTPRequests.Total), "", 0)
-	nps.mb.RecordNginxHTTPRequestCountDataPoint(now, int64(stats.HTTPRequests.Current))
+
+	requestsDiff := int64(stats.HTTPRequests.Total) - int64(nps.previousHTTPRequestsTotal)
+	nps.mb.RecordNginxHTTPRequestCountDataPoint(now, requestsDiff)
+	nps.previousHTTPRequestsTotal = stats.HTTPRequests.Total
 
 	nps.recordCacheMetrics(stats, now)
 	nps.recordHTTPLimitMetrics(stats, now)

internal/collector/nginxplusreceiver/scraper_test.go

@@ -58,6 +58,8 @@ func TestScraper(t *testing.T) {
 		},
 	}
 
+	scraper.previousHTTPRequestsTotal = 3
+
 	actualMetrics, err := scraper.Scrape(context.Background())
 	require.NoError(t, err)
 

internal/collector/nginxplusreceiver/testdata/expected.yaml

@@ -295,7 +295,7 @@ resourceMetrics:
             gauge:
               aggregationTemporality: 2
               dataPoints:
-                - asInt: "3"
+                - asInt: "44"
                   timeUnixNano: "1000000"
               isMonotonic: true
             unit: requests