From 1eb86d4b5f23f4ea6df666fe2ae92c226a25db2b Mon Sep 17 00:00:00 2001
From: Owen Diehl <ow.diehl@gmail.com>
Date: Wed, 4 Nov 2020 07:47:01 -0500
Subject: [PATCH] Only applies entry limits to non-SampleExprs. (#2850)

* only applies entry limits to non-SampleExprs. updates docs

* fixes some test case formatting
---
 docs/sources/configuration/_index.md |  2 +-
 pkg/logentry/stages/drop_test.go     |  6 +++++-
 pkg/logentry/stages/metrics_test.go  |  2 +-
 pkg/querier/http.go                  | 18 ++++++++++++++----
 4 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/docs/sources/configuration/_index.md b/docs/sources/configuration/_index.md
index 10c175d79e782..2d297b626f2ae 100644
--- a/docs/sources/configuration/_index.md
+++ b/docs/sources/configuration/_index.md
@@ -1598,7 +1598,7 @@ logs in Loki.
 # CLI flag: -distributor.max-line-size
 [max_line_size: <string> | default = none ]
 
-# Maximum number of log entries that will be returned for a query. 0 to disable.
+# Maximum number of log entries that will be returned for a query.
 # CLI flag: -validation.max-entries-limit
 [max_entries_limit_per_query: <int> | default = 5000 ]
 
diff --git a/pkg/logentry/stages/drop_test.go b/pkg/logentry/stages/drop_test.go
index 3d8cabf65f6b0..36c048a94d42a 100644
--- a/pkg/logentry/stages/drop_test.go
+++ b/pkg/logentry/stages/drop_test.go
@@ -342,7 +342,11 @@ func Test_validateDropConfig(t *testing.T) {
 			config: &DropConfig{
 				OlderThan: &dropInvalidDur,
 			},
-			wantErr: fmt.Errorf(ErrDropStageInvalidDuration, dropInvalidDur, "time: unknown unit \"y\" in duration \"10y\""),
+			wantErr: fmt.Errorf(
+				ErrDropStageInvalidDuration,
+				dropInvalidDur,
+				"time: unknown unit y in duration 10y",
+			),
 		},
 		{
 			name: "Invalid Config",
diff --git a/pkg/logentry/stages/metrics_test.go b/pkg/logentry/stages/metrics_test.go
index bf98b917616f8..33319e37272c1 100644
--- a/pkg/logentry/stages/metrics_test.go
+++ b/pkg/logentry/stages/metrics_test.go
@@ -222,7 +222,7 @@ func Test(t *testing.T) {
 					IdleDuration: &metricTestInvalidIdle,
 				},
 			},
-			errors.Errorf(ErrInvalidIdleDur, "time: unknown unit \"f\" in duration \"10f\""),
+			errors.Errorf(ErrInvalidIdleDur, "time: unknown unit f in duration 10f"),
 		},
 		"valid": {
 			MetricsConfig{
diff --git a/pkg/querier/http.go b/pkg/querier/http.go
index d9da166c26086..99e417c8ab62d 100644
--- a/pkg/querier/http.go
+++ b/pkg/querier/http.go
@@ -42,7 +42,7 @@ func (q *Querier) RangeQueryHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if err := q.validateEntriesLimits(ctx, request.Limit); err != nil {
+	if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
 		serverutil.WriteError(err, w)
 		return
 	}
@@ -82,7 +82,7 @@ func (q *Querier) InstantQueryHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if err := q.validateEntriesLimits(ctx, request.Limit); err != nil {
+	if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
 		serverutil.WriteError(err, w)
 		return
 	}
@@ -139,7 +139,7 @@ func (q *Querier) LogQueryHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	if err := q.validateEntriesLimits(ctx, request.Limit); err != nil {
+	if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
 		serverutil.WriteError(err, w)
 		return
 	}
@@ -345,12 +345,22 @@ func parseRegexQuery(httpRequest *http.Request) (string, error) {
 	return query, nil
 }
 
-func (q *Querier) validateEntriesLimits(ctx context.Context, limit uint32) error {
+func (q *Querier) validateEntriesLimits(ctx context.Context, query string, limit uint32) error {
 	userID, err := user.ExtractOrgID(ctx)
 	if err != nil {
 		return httpgrpc.Errorf(http.StatusBadRequest, err.Error())
 	}
 
+	expr, err := logql.ParseExpr(query)
+	if err != nil {
+		return err
+	}
+
+	// entry limit does not apply to metric queries.
+	if _, ok := expr.(logql.SampleExpr); ok {
+		return nil
+	}
+
 	maxEntriesLimit := q.limits.MaxEntriesLimitPerQuery(userID)
 	if int(limit) > maxEntriesLimit && maxEntriesLimit != 0 {
 		return httpgrpc.Errorf(http.StatusBadRequest,