Fix cortex query seconds total

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## master / unreleased
 
+* [BUGFIX] Query-Frontend: `cortex_query_seconds_total` now return seconds not nanoseconds. #3589
 * [ENHANCEMENT] Memberlist: add status page (/memberlist) with available details about memberlist-based KV store and memberlist cluster. It's also possible to view KV values in Go struct or JSON format, or download for inspection. #3575
 * [ENHANCEMENT] Memberlist: client can now keep a size-bounded buffer with sent and received messages and display them in the admin UI (/memberlist) for troubleshooting. #3581
 

pkg/frontend/transport/handler.go

@@ -152,7 +152,7 @@ func (f *Handler) reportQueryStats(r *http.Request, queryString url.Values, quer
 	}
 
 	// Track stats.
-	f.querySeconds.WithLabelValues(userID).Add(float64(stats.LoadWallTime()))
+	f.querySeconds.WithLabelValues(userID).Add(stats.LoadWallTime().Seconds())
 
 	// Log stats.
 	logMessage := append([]interface{}{