From 205233d9a769bec6bcf8a381d40b01c3ef051a6b Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@gmail.com>
Date: Mon, 25 Nov 2019 18:55:12 +0200
Subject: [PATCH] app/vmselect/promql: remove zero timeseries from
 `prometheus_buckets` output

---
 app/vmselect/promql/transform.go | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/app/vmselect/promql/transform.go b/app/vmselect/promql/transform.go
index aacfa2bfbe..e89c0ddbb3 100644
--- a/app/vmselect/promql/transform.go
+++ b/app/vmselect/promql/transform.go
@@ -343,12 +343,24 @@ func vmrangeBucketsToLE(tss []*timeseries) []*timeseries {
 		ts.MetricName.AddTag("le", leStr)
 		return &ts
 	}
+	isZeroTS := func(ts *timeseries) bool {
+		for _, v := range ts.Values {
+			if v > 0 {
+				return false
+			}
+		}
+		return true
+	}
 	for _, xss := range m {
 		sort.Slice(xss, func(i, j int) bool { return xss[i].end < xss[j].end })
 		xssNew := make([]x, 0, len(xss)+2)
 		var xsPrev x
 		for _, xs := range xss {
 			ts := xs.ts
+			if isZeroTS(ts) {
+				// Skip time series with zeros. They are substituted by xssNew below.
+				continue
+			}
 			if xs.start != xsPrev.end {
 				xssNew = append(xssNew, x{
 					endStr: xs.startStr,