From 5274b4a2d8ed4f33ab3dd48e3e9c9b7135e835a3 Mon Sep 17 00:00:00 2001
From: Justin Jung <jungjust@amazon.com>
Date: Mon, 13 Mar 2023 21:33:26 -0700
Subject: [PATCH] Disable scalar for vertical sharding

Signed-off-by: Justin Jung <jungjust@amazon.com>
---
 CHANGELOG.md                       | 1 +
 pkg/querysharding/analyzer.go      | 2 +-
 pkg/querysharding/analyzer_test.go | 4 ++++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 964a3fd328f..da7a7384cfc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,7 @@ We use *breaking :warning:* to mark changes that are not backward compatible (re
 ### Changed
 - [#6168](https://github.com/thanos-io/thanos/pull/6168) Receiver: Make ketama hashring fail early when configured with number of nodes lower than the replication factor.
 - [#6201](https://github.com/thanos-io/thanos/pull/6201) Query-Frontend: Disable absent and absent_over_time for vertical sharding.
+- [#6212](https://github.com/thanos-io/thanos/pull/6212) Query-Frontend: Disable scalar for vertical sharding.
 
 ### Removed
 
diff --git a/pkg/querysharding/analyzer.go b/pkg/querysharding/analyzer.go
index 37a0d30296e..12cb1b9a1a0 100644
--- a/pkg/querysharding/analyzer.go
+++ b/pkg/querysharding/analyzer.go
@@ -105,7 +105,7 @@ func (a *QueryAnalyzer) Analyze(query string) (QueryAnalysis, error) {
 				if n.Func.Name == "label_join" || n.Func.Name == "label_replace" {
 					dstLabel := stringFromArg(n.Args[1])
 					dynamicLabels = append(dynamicLabels, dstLabel)
-				} else if n.Func.Name == "absent_over_time" || n.Func.Name == "absent" {
+				} else if n.Func.Name == "absent_over_time" || n.Func.Name == "absent" || n.Func.Name == "scalar" {
 					isShardable = false
 					return notShardableErr
 				}
diff --git a/pkg/querysharding/analyzer_test.go b/pkg/querysharding/analyzer_test.go
index 6faa6e839fb..b86721706cf 100644
--- a/pkg/querysharding/analyzer_test.go
+++ b/pkg/querysharding/analyzer_test.go
@@ -75,6 +75,10 @@ http_requests_total`,
 			name:       "absent is not shardable",
 			expression: `sum by (url) (absent(http_requests_total{code="400"}))`,
 		},
+		{
+			name:       "scalar is not shardable",
+			expression: `scalar(sum by (url) (http_requests_total{code="400"}))`,
+		},
 	}
 
 	shardableByLabels := []testCase{