From 61c7f6beaefbb1a13fc39f3e8785b0bcd023eaaa Mon Sep 17 00:00:00 2001
From: Aliaksandr Valialkin <valyala@victoriametrics.com>
Date: Mon, 11 Apr 2022 12:25:30 +0300
Subject: [PATCH] app/vmselect/promql: allow calling
 InitRollupResultCache+StopRollupResultCache multiple times during tests

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2406
---
 app/vmselect/promql/rollup_result_cache.go    | 16 ++++++++++----
 .../promql/rollup_result_cache_test.go        | 21 +++++++++++++++++++
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/app/vmselect/promql/rollup_result_cache.go b/app/vmselect/promql/rollup_result_cache.go
index 9ffd38a92..87f36fee8 100644
--- a/app/vmselect/promql/rollup_result_cache.go
+++ b/app/vmselect/promql/rollup_result_cache.go
@@ -97,6 +97,11 @@ var (
 )
 
 // InitRollupResultCache initializes the rollupResult cache
+//
+// if cachePath is empty, then the cache isn't stored to persistent disk.
+//
+// ResetRollupResultCache must be called when the cache must be reset.
+// StopRollupResultCache must be called when the cache isn't needed anymore.
 func InitRollupResultCache(cachePath string) {
 	rollupResultCachePath = cachePath
 	startTime := time.Now()
@@ -133,16 +138,19 @@ func InitRollupResultCache(cachePath string) {
 			rollupResultCachePath, time.Since(startTime).Seconds(), fcs().EntriesCount, fcs().BytesSize)
 	}
 
-	metrics.NewGauge(`vm_cache_entries{type="promql/rollupResult"}`, func() float64 {
+	// Use metrics.GetOrCreateGauge instead of metrics.NewGauge,
+	// so InitRollupResultCache+StopRollupResultCache could be called multiple times in tests.
+	// See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2406
+	metrics.GetOrCreateGauge(`vm_cache_entries{type="promql/rollupResult"}`, func() float64 {
 		return float64(fcs().EntriesCount)
 	})
-	metrics.NewGauge(`vm_cache_size_bytes{type="promql/rollupResult"}`, func() float64 {
+	metrics.GetOrCreateGauge(`vm_cache_size_bytes{type="promql/rollupResult"}`, func() float64 {
 		return float64(fcs().BytesSize)
 	})
-	metrics.NewGauge(`vm_cache_requests_total{type="promql/rollupResult"}`, func() float64 {
+	metrics.GetOrCreateGauge(`vm_cache_requests_total{type="promql/rollupResult"}`, func() float64 {
 		return float64(fcs().GetCalls)
 	})
-	metrics.NewGauge(`vm_cache_misses_total{type="promql/rollupResult"}`, func() float64 {
+	metrics.GetOrCreateGauge(`vm_cache_misses_total{type="promql/rollupResult"}`, func() float64 {
 		return float64(fcs().Misses)
 	})
 
diff --git a/app/vmselect/promql/rollup_result_cache_test.go b/app/vmselect/promql/rollup_result_cache_test.go
index de9a25e71..eac9224bb 100644
--- a/app/vmselect/promql/rollup_result_cache_test.go
+++ b/app/vmselect/promql/rollup_result_cache_test.go
@@ -3,11 +3,32 @@ package promql
 import (
 	"testing"
 
+	"github.com/VictoriaMetrics/VictoriaMetrics/lib/fs"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/storage"
 	"github.com/VictoriaMetrics/metricsql"
 )
 
+func TestRollupResultCacheInitStop(t *testing.T) {
+	t.Run("inmemory", func(t *testing.T) {
+		for i := 0; i < 5; i++ {
+			InitRollupResultCache("")
+			StopRollupResultCache()
+		}
+	})
+	t.Run("file-based", func(t *testing.T) {
+		cacheFilePath := "test-rollup-result-cache"
+		for i := 0; i < 3; i++ {
+			InitRollupResultCache(cacheFilePath)
+			StopRollupResultCache()
+		}
+		fs.MustRemoveAll(cacheFilePath)
+	})
+}
+
 func TestRollupResultCache(t *testing.T) {
+	InitRollupResultCache("")
+	defer StopRollupResultCache()
+
 	ResetRollupResultCache()
 	window := int64(456)
 	ec := &EvalConfig{