From 2daae9eba80b007720338362506a6faf6f10e167 Mon Sep 17 00:00:00 2001
From: Ivana Huckova <30407135+ivanahuckova@users.noreply.github.com>
Date: Fri, 5 Nov 2021 18:00:48 +0100
Subject: [PATCH] Prometheus: Fix showing of errors (#41356)

* Prometheus: Fix showing of errors

* Refactor and add comment
---
 pkg/tsdb/prometheus/time_series_query.go | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/pkg/tsdb/prometheus/time_series_query.go b/pkg/tsdb/prometheus/time_series_query.go
index b663218f34e..1fbbb47b8d1 100644
--- a/pkg/tsdb/prometheus/time_series_query.go
+++ b/pkg/tsdb/prometheus/time_series_query.go
@@ -71,9 +71,9 @@ func (s *Service) executeTimeSeriesQuery(ctx context.Context, req *backend.Query
 			if err != nil {
 				plog.Error("Range query failed", "query", query.Expr, "err", err)
 				result.Responses[query.RefId] = backend.DataResponse{Error: err}
-			} else {
-				response[RangeQueryType] = rangeResponse
+				continue
 			}
+			response[RangeQueryType] = rangeResponse
 		}
 
 		if query.InstantQuery {
@@ -81,16 +81,17 @@ func (s *Service) executeTimeSeriesQuery(ctx context.Context, req *backend.Query
 			if err != nil {
 				plog.Error("Instant query failed", "query", query.Expr, "err", err)
 				result.Responses[query.RefId] = backend.DataResponse{Error: err}
-			} else {
-				response[InstantQueryType] = instantResponse
+				continue
 			}
+			response[InstantQueryType] = instantResponse
 		}
 
+		// This is a special case
+		// If exemplar query returns error, we want to only log it and continue with other results processing
 		if query.ExemplarQuery {
 			exemplarResponse, err := client.QueryExemplars(ctx, query.Expr, timeRange.Start, timeRange.End)
 			if err != nil {
 				plog.Error("Exemplar query failed", "query", query.Expr, "err", err)
-				result.Responses[query.RefId] = backend.DataResponse{Error: err}
 			} else {
 				response[ExemplarQueryType] = exemplarResponse
 			}