From 1242aa554780715f0d4367bda7be75a6bccffa72 Mon Sep 17 00:00:00 2001
From: Ivan Kalita <ivan.kalita@grafana.com>
Date: Mon, 9 Mar 2026 14:19:16 +0100
Subject: [PATCH] feat(loki): allow disabling cache for query_range requests
 (#21112)

Allows disabling results cache via Cache-Control headers for query_range requests (the same way it's done for instant queries).
---
 pkg/querier/queryrange/codec.go      |  5 +++++
 pkg/querier/queryrange/codec_test.go | 29 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/pkg/querier/queryrange/codec.go b/pkg/querier/queryrange/codec.go
index 2ba6f4740b..edf18a20f0 100644
--- a/pkg/querier/queryrange/codec.go
+++ b/pkg/querier/queryrange/codec.go
@@ -342,6 +342,11 @@ func (Codec) DecodeRequest(_ context.Context, r *http.Request, _ []string) (quer
 		if err != nil {
 			return nil, httpgrpc.Errorf(http.StatusBadRequest, "%s", err.Error())
 		}
+
+		req.CachingOptions = queryrangebase.CachingOptions{
+			Disabled: disableCacheReq,
+		}
+
 		return req, nil
 	case InstantQueryOp:
 		req, err := parseInstantQuery(r)
diff --git a/pkg/querier/queryrange/codec_test.go b/pkg/querier/queryrange/codec_test.go
index ee0f5e171b..b4e9c3df08 100644
--- a/pkg/querier/queryrange/codec_test.go
+++ b/pkg/querier/queryrange/codec_test.go
@@ -341,6 +341,35 @@ func Test_codec_DecodeRequest_cacheHeader(t *testing.T) {
 				},
 			},
 		},
+		{
+			"query_range",
+			func() (*http.Request, error) {
+				req, err := http.NewRequest(
+					http.MethodGet,
+					fmt.Sprintf(`/query_range?start=%d&end=%d&query={foo="bar"}&step=10&limit=200&direction=FORWARD`, start.UnixNano(), end.UnixNano()),
+					nil,
+				)
+				if err == nil {
+					req.Header.Set(cacheControlHeader, noCacheVal)
+				}
+				return req, err
+			},
+			&LokiRequest{
+				Query:     `{foo="bar"}`,
+				Limit:     200,
+				Step:      10000, // step is expected in ms
+				Direction: logproto.FORWARD,
+				Path:      "/query_range",
+				StartTs:   start,
+				EndTs:     end,
+				Plan: &plan.QueryPlan{
+					AST: syntax.MustParseExpr(`{foo="bar"}`),
+				},
+				CachingOptions: queryrangebase.CachingOptions{
+					Disabled: true,
+				},
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {