QueryFronted should send request to queriers when query_range has start==end (#4877)

* Cortex should still send the request to upstream when Start == end

Signed-off-by: Alan Protasio <[email protected]>

* Changelog

Signed-off-by: Alan Protasio <[email protected]>

* Fix test

Signed-off-by: Alan Protasio <[email protected]>

Signed-off-by: Alan Protasio <[email protected]>

Author: alanprot

CHANGELOG.md

@@ -59,6 +59,7 @@
 * [BUGFIX] Memberlist: Add join with no retrying when starting service. #4804
 * [BUGFIX] Ruler: Fix /ruler/rule_groups returns YAML with extra fields. #4767
 * [BUGFIX] Respecting `-tracing.otel.sample-ratio` configuration when enabling OpenTelemetry tracing with X-ray. #4862
+* [BUGFIX] QueryFrontend: fixed query_range requests when query has `start` equals to `end`. #4877
 
 ## 1.13.0 2022-07-14
 

pkg/querier/tripperware/queryrange/split_by_interval.go

@@ -69,6 +69,11 @@ func (s splitByInterval) Do(ctx context.Context, r tripperware.Request) (tripper
 }
 
 func splitQuery(r tripperware.Request, interval time.Duration) ([]tripperware.Request, error) {
+	// If Start == end we should just run the original request
+	if r.GetStart() == r.GetEnd() {
+		return []tripperware.Request{r}, nil
+	}
+
 	// Replace @ modifier function to their respective constant values in the query.
 	// This way subqueries will be evaluated at the same time as the parent query.
 	query, err := evaluateAtModifierFunction(r.GetQuery(), r.GetStart(), r.GetEnd())

pkg/querier/tripperware/queryrange/split_by_interval_test.go

@@ -84,6 +84,23 @@ func TestSplitQuery(t *testing.T) {
 			},
 			interval: day,
 		},
+		{
+			input: &PrometheusRequest{
+				Start: 60 * 60 * seconds,
+				End:   60 * 60 * seconds,
+				Step:  15 * seconds,
+				Query: "foo",
+			},
+			expected: []tripperware.Request{
+				&PrometheusRequest{
+					Start: 60 * 60 * seconds,
+					End:   60 * 60 * seconds,
+					Step:  15 * seconds,
+					Query: "foo",
+				},
+			},
+			interval: day,
+		},
 		{
 			input: &PrometheusRequest{
 				Start: 0,