Ignore time range in /series request for the blocks storage (#2617)

* Ignore time range in /series request for the blocks storage

Signed-off-by: Marco Pracucci <[email protected]>

* Updated CHANGELOG

Signed-off-by: Marco Pracucci <[email protected]>

* Update CHANGELOG.md

Signed-off-by: Marco Pracucci <[email protected]>

Co-authored-by: Peter Štibraný <[email protected]>

* Update pkg/ingester/ingester_v2.go

Signed-off-by: Marco Pracucci <[email protected]>

Co-authored-by: Peter Štibraný <[email protected]>

Co-authored-by: Peter Štibraný <[email protected]>

Author: pracucci

CHANGELOG.md

@@ -38,6 +38,7 @@
 * [BUGFIX] QueryFrontend: fixed a situation where HTTP error is ignored and an incorrect status code is set. #2590
 * [BUGFIX] Ingester: Fix an ingester starting up in the JOINING state and staying there forever. #2565
 * [BUGFIX] QueryFrontend: fixed a panic (`integer divide by zero`) in the query-frontend. The query-frontend now requires the `-querier.default-evaluation-interval` config to be set to the same value of the querier. #2603
+* [BUGFIX] Experimental TSDB: when the querier receives a `/series` request with a time range older than the data stored in the ingester, it now ignores the requested time range and returns known series anyway instead of returning an empty response. This aligns the behaviour with the chunks storage. #2617
 
 ## 1.1.0 / 2020-05-21
 

pkg/ingester/ingester_v2.go

@@ -527,13 +527,16 @@ func (i *Ingester) v2MetricsForLabelMatchers(ctx context.Context, req *client.Me
 	}
 
 	// Parse the request
-	from, to, matchersSet, err := client.FromMetricsForLabelMatchersRequest(req)
+	_, _, matchersSet, err := client.FromMetricsForLabelMatchersRequest(req)
 	if err != nil {
 		return nil, err
 	}
 
-	// Create a new instance of the TSDB querier
-	q, err := db.Querier(int64(from), int64(to))
+	// Since ingester runs with a very limited TSDB retention, we can (and should) query
+	// metrics without any time range bound, otherwise when we receive a request with a time
+	// range older then the ingester's data we return an empty response instead of returning
+	// the currently known series.
+	q, err := db.Querier(0, math.MaxInt64)
 	if err != nil {
 		return nil, err
 	}

pkg/ingester/ingester_v2_test.go

@@ -883,16 +883,17 @@ func Test_Ingester_v2MetricsForLabelMatchers(t *testing.T) {
 				{Labels: client.FromLabelsToLabelAdapters(fixtures[2].lbls)},
 			},
 		},
-		"should filter metrics by time range": {
-			from: 100000,
-			to:   100000,
+		"should NOT filter metrics by time range to always return known metrics even when queried for older time ranges": {
+			from: 100,
+			to:   1000,
 			matchers: []*client.LabelMatchers{{
 				Matchers: []*client.LabelMatcher{
 					{Type: client.EQUAL, Name: model.MetricNameLabel, Value: "test_1"},
 				},
 			}},
 			expected: []*client.Metric{
 				{Labels: client.FromLabelsToLabelAdapters(fixtures[0].lbls)},
+				{Labels: client.FromLabelsToLabelAdapters(fixtures[1].lbls)},
 			},
 		},
 		"should not return duplicated metrics on overlapping matchers": {