Add metrics for cached queries + cache hit/miss

Dockerfile

@@ -2,6 +2,7 @@ FROM gcr.io/distroless/base-debian12:nonroot
 WORKDIR /go/src/app
 ARG TARGETARCH
 ARG TARGETOS
+# silly workaround for distroless image as no chmod is available
+COPY --chmod=777 --chown=nonroot:nonroot static/app /go/src/app
 ADD dist/bot-$TARGETOS-$TARGETARCH /go/src/app/graphql-proxy
-ADD static/default-ratelimit.json /app/ratelimit.json
 ENTRYPOINT ["/go/src/app/graphql-proxy"]

README.md

@@ -23,6 +23,7 @@ This project is in active use by [telegram-bot.app](https://telegram-bot.app), a
     - [Blocking introspection](#blocking-introspection)
   - [API endpoints](#api-endpoints)
     - [Ban or unban the user](#ban-or-unban-the-user)
+    - [Cache operations](#cache-operations)
   - [General](#general)
     - [Metrics which matter](#metrics-which-matter)
     - [Healthcheck](#healthcheck)
@@ -236,6 +237,11 @@ To do so - you need to enable the api by setting env variable `ENABLE_API=true`
 * `POST /api/user-ban` - ban the user from accessing the application
 * `POST /api/user-unban` - unban the user from accessing the application
 
+#### Cache operations
+
+* `POST /api/cache-clear` - clear the cache
+* `GET /api/cache-stats` - get the cache statistics ( hits, misses, size )
+
 Both endpoints require the `user_id` parameter to be present in the request body and allow you to provide the reason for the ban.
 
 Example request:

api.go

@@ -23,6 +23,8 @@ func enableApi() {
 		api := apiserver.Group("/api")
 		api.Post("/user-ban", apiBanUser)
 		api.Post("/user-unban", apiUnbanUser)
+		api.Post("/cache-clear", apiClearCache)
+		api.Get("/cache-stats", apiCacheStats)
 
 		go periodicallyReloadBannedUsers()
 		err := apiserver.Listen(fmt.Sprintf(":%d", cfg.Server.ApiPort))
@@ -50,6 +52,21 @@ func checkIfUserIsBanned(c *fiber.Ctx, userID string) bool {
 	return found
 }
 
+func apiClearCache(c *fiber.Ctx) error {
+	cfg.Logger.Debug("Clearing cache via API", nil)
+	cfg.Cache.CacheClient.ClearCache()
+	cfg.Logger.Info("Cache cleared via API", nil)
+	c.Status(200).SendString("OK: cache cleared")
+	return nil
+}
+
+func apiCacheStats(c *fiber.Ctx) error {
+	stats := cfg.Cache.CacheClient.ShowStats()
+	cfg.Logger.Debug("Getting cache stats via API", map[string]interface{}{"stats": stats})
+	c.JSON(stats)
+	return nil
+}
+
 type apiBanUserRequest struct {
 	UserID string `json:"user_id"`
 	Reason string `json:"reason"`

cache/cache.go

@@ -18,6 +18,8 @@ type Cache struct {
 	globalTTL      time.Duration
 	compressPool   sync.Pool
 	decompressPool sync.Pool
+	cacheHits      int
+	cacheMisses    int
 	sync.RWMutex   // Reintroduced to provide lock methods
 }
 
@@ -75,14 +77,16 @@ func (c *Cache) Get(key string) ([]byte, bool) {
 
 	entry, ok := c.entries.Load(key)
 	if !ok || entry.(CacheEntry).ExpiresAt.Before(time.Now()) {
+		c.cacheMisses++
 		return nil, false
 	}
 	compressedValue := entry.(CacheEntry).Value
 	value, err := c.decompress(compressedValue)
 	if err != nil {
+		c.cacheMisses++
 		return nil, false
 	}
-
+	c.cacheHits++
 	return value, true
 }
 
@@ -109,6 +113,34 @@ func (c *Cache) CleanExpiredEntries() {
 	})
 }
 
+type CacheStats struct {
+	CachedQueries int `json:"cached_queries"`
+	CacheHits     int `json:"cache_hits"`
+	CacheMisses   int `json:"cache_misses"`
+}
+
+func (c *Cache) ShowStats() CacheStats {
+	c.RLock()
+	defer c.RUnlock()
+	var count int
+	c.entries.Range(func(_, _ interface{}) bool {
+		count++
+		return true
+	})
+	cs := CacheStats{
+		CachedQueries: count,
+		CacheHits:     c.cacheHits,
+		CacheMisses:   c.cacheMisses,
+	}
+	return cs
+}
+
+func (c *Cache) ClearCache() {
+	c.cacheHits = 0
+	c.cacheMisses = 0
+	c.entries = sync.Map{}
+}
+
 func (c *Cache) compress(data []byte) ([]byte, error) {
 	w := c.compressPool.Get().(*gzip.Writer)
 	defer c.compressPool.Put(w)

cache/cache_bench_test.go

@@ -0,0 +1,54 @@
+package libpack_cache
+
+import (
+	"testing"
+	"time"
+)
+
+// Assume that New function initializes the cache and it is defined somewhere in the libpack_cache package.
+
+func BenchmarkCacheSet(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache with a TTL of 30 seconds
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+
+	b.ResetTimer() // Reset the timer to exclude the setup time from the benchmark
+
+	for i := 0; i < b.N; i++ {
+		cache.Set(key, value, 5*time.Second)
+	}
+}
+
+func BenchmarkCacheGet(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+	cache.Set(key, value, 5*time.Second) // Pre-set a value to retrieve
+
+	b.ResetTimer() // Start timing
+
+	for i := 0; i < b.N; i++ {
+		_, _ = cache.Get(key)
+	}
+}
+
+func BenchmarkCacheExpire(b *testing.B) {
+	key := "benchmark-expire-key"
+	value := []byte("benchmark-value")
+	ttl := 5 * time.Millisecond // Setting a short TTL for quick expiration
+
+	for i := 0; i < b.N; i++ {
+		cache := New(30 * time.Second)
+		cache.Set(key, value, ttl)
+		time.Sleep(ttl) // Wait for the key to expire
+		_, _ = cache.Get(key)
+	}
+}
+
+func BenchmarkCacheStats(b *testing.B) {
+	cache := New(30 * time.Second) // Initializing the cache
+	key := "benchmark-key"
+	value := []byte("benchmark-value")
+	cache.Set(key, value, 5*time.Second) // Pre-set a value to retrieve
+	cache.Get(key)
+}

cache/cache_test.go

@@ -110,3 +110,36 @@ func (suite *CacheTestSuite) Test_CacheExpire() {
 		})
 	}
 }
+
+func (suite *CacheTestSuite) Test_CacheStats() {
+	cache := New(30 * time.Second)
+	tests := []struct {
+		name        string
+		cache_value string
+		ttl         time.Duration
+	}{
+		{
+			name:        "test1",
+			cache_value: "test1-123",
+			ttl:         2 * time.Second,
+		},
+		{
+			name:        "test2",
+			cache_value: "test2-123",
+			ttl:         5 * time.Second,
+		},
+	}
+	for _, tt := range tests {
+		suite.T().Run(tt.name, func(t *testing.T) {
+			cache.Set(tt.name, []byte(tt.name), tt.ttl)
+			c, ok := cache.Get(tt.name)
+			suite.Equal(true, ok)
+			suite.Equal(tt.name, string(c))
+		})
+	}
+	cache.Get("non-existent-non-cached-key")
+	stats := cache.ShowStats()
+	suite.Equal(2, stats.CacheHits, "CacheHits")
+	suite.Equal(1, stats.CacheMisses, "CacheMisses")
+	suite.Equal(2, stats.CachedQueries, "CachedQueries")
+}

go.mod

@@ -5,7 +5,7 @@ go 1.21
 require (
 	github.com/VictoriaMetrics/metrics v1.33.1
 	github.com/avast/retry-go/v4 v4.6.0
-	github.com/goccy/go-json v0.10.2
+	github.com/goccy/go-json v0.10.3
 	github.com/gofiber/fiber/v2 v2.52.4
 	github.com/gofrs/flock v0.8.1
 	github.com/google/uuid v1.6.0
@@ -14,9 +14,9 @@ require (
 	github.com/lukaszraczylo/ask v0.0.0-20230927103145-2ff1123b4415
 	github.com/lukaszraczylo/go-ratecounter v0.1.8
 	github.com/lukaszraczylo/go-simple-graphql v1.2.14
-	github.com/rs/zerolog v1.32.0
+	github.com/rs/zerolog v1.33.0
 	github.com/stretchr/testify v1.9.0
-	github.com/valyala/fasthttp v1.53.0
+	github.com/valyala/fasthttp v1.54.0
 )
 
 require (
@@ -37,11 +37,11 @@ require (
 	github.com/valyala/tcplisten v1.0.0 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	golang.org/x/exp v0.0.0-20231006140011-7918f672742d // indirect
-	golang.org/x/net v0.25.0 // indirect
+	golang.org/x/net v0.26.0 // indirect
 	golang.org/x/sync v0.7.0 // indirect
-	golang.org/x/sys v0.20.0 // indirect
-	golang.org/x/term v0.20.0 // indirect
-	golang.org/x/text v0.15.0 // indirect
+	golang.org/x/sys v0.21.0 // indirect
+	golang.org/x/term v0.21.0 // indirect
+	golang.org/x/text v0.16.0 // indirect
 	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -8,8 +8,8 @@ github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSV
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/goccy/go-json v0.10.2 h1:CrxCmQqYDkv1z7lO7Wbh2HN93uovUHgrECaO5ZrCXAU=
-github.com/goccy/go-json v0.10.2/go.mod h1:6MelG93GURQebXPDq3khkgXZkazVtN9CRI+MGFi0w8I=
+github.com/goccy/go-json v0.10.3 h1:KZ5WoDbxAIgm2HNbYckL0se1fHD6rz5j4ywS6ebzDqA=
+github.com/goccy/go-json v0.10.3/go.mod h1:oq7eo15ShAhp70Anwd5lgX2pLfOS3QCiwU/PULtXL6M=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/gofiber/fiber/v2 v2.52.4 h1:P+T+4iK7VaqUsq2PALYEfBBo6bJZ4q3FP8cZ84EggTM=
 github.com/gofiber/fiber/v2 v2.52.4/go.mod h1:KEOE+cXMhXG0zHc9d8+E38hoX+ZN7bhOtgeF2oT6jrQ=
@@ -57,14 +57,14 @@ github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/f
 github.com/rogpeppe/go-internal v1.11.0 h1:cWPaGQEPrBb5/AsnsZesgZZ9yb1OQ+GOISoDNXVBh4M=
 github.com/rogpeppe/go-internal v1.11.0/go.mod h1:ddIwULY96R17DhadqLgMfk9H9tvdUzkipdSkR5nkCZA=
 github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
-github.com/rs/zerolog v1.32.0 h1:keLypqrlIjaFsbmJOBdB/qvyF8KEtCWHwobLp5l/mQ0=
-github.com/rs/zerolog v1.32.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
+github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
+github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
 github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
-github.com/valyala/fasthttp v1.53.0 h1:lW/+SUkOxCx2vlIu0iaImv4JLrVRnbbkpCoaawvA4zc=
-github.com/valyala/fasthttp v1.53.0/go.mod h1:6dt4/8olwq9QARP/TDuPmWyWcl4byhpvTJ4AAtcz+QM=
+github.com/valyala/fasthttp v1.54.0 h1:cCL+ZZR3z3HPLMVfEYVUMtJqVaui0+gu7Lx63unHwS0=
+github.com/valyala/fasthttp v1.54.0/go.mod h1:6dt4/8olwq9QARP/TDuPmWyWcl4byhpvTJ4AAtcz+QM=
 github.com/valyala/fastrand v1.1.0 h1:f+5HkLW4rsgzdNoleUOB69hyT9IlD2ZQh9GyDMfb5G8=
 github.com/valyala/fastrand v1.1.0/go.mod h1:HWqCzkrkg6QXT8V2EXWvXCoow7vLwOFN002oeRzjapQ=
 github.com/valyala/histogram v1.2.0 h1:wyYGAZZt3CpwUiIb9AU/Zbllg1llXyrtApRS815OLoQ=
@@ -75,19 +75,19 @@ github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavM
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d h1:jtJma62tbqLibJ5sFQz8bKtEM8rJBtfilJ2qTU199MI=
 golang.org/x/exp v0.0.0-20231006140011-7918f672742d/go.mod h1:ldy0pHrwJyGW56pPQzzkH36rKxoZW1tw7ZJpeKx+hdo=
-golang.org/x/net v0.25.0 h1:d/OCCoBEUq33pjydKrGQhw7IlUPI2Oylr+8qLx49kac=
-golang.org/x/net v0.25.0/go.mod h1:JkAGAh7GEvH74S6FOH42FLoXpXbE/aqXSrIQjXgsiwM=
+golang.org/x/net v0.26.0 h1:soB7SVo0PWrY4vPW/+ay0jKDNScG2X9wFeYlXIvJsOQ=
+golang.org/x/net v0.26.0/go.mod h1:5YKkiSynbBIh3p6iOc/vibscux0x38BZDkn8sCUPxHE=
 golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
 golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
-golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
-golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
-golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
-golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.21.0 h1:WVXCp+/EBEHOj53Rvu+7KiT/iElMrO8ACK16SMZ3jaA=
+golang.org/x/term v0.21.0/go.mod h1:ooXLefLobQVslOqselCNF4SxFAaoS6KujMbsGzSDmX0=
+golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
+golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"os"
 	"strings"
+	"sync"
 
 	"github.com/gofiber/fiber/v2/middleware/proxy"
 	"github.com/gookit/goutil/envutil"
@@ -13,6 +14,7 @@ import (
 )
 
 var cfg *config
+var once sync.Once
 
 // function get value from the env where the value can be anything
 func getDetailsFromEnv[T any](key string, defaultValue T) T {
@@ -79,7 +81,9 @@ func parseConfig() {
 
 	enableCache() // takes close to no resources, but can be used with dynamic query cache
 	loadRatelimitConfig()
-	enableApi()
+	once.Do(func() {
+		go enableApi()
+	})
 	prepareQueriesAndExemptions()
 }
 

main_test.go

@@ -33,6 +33,7 @@ func (suite *Tests) SetupTest() {
 		},
 	)
 	parseConfig()
+	enableApi()
 	StartMonitoringServer()
 	cfg.Logger = libpack_logging.NewLogger()
 	// Setup environment variables here if needed

monitoring/defaults.go

@@ -5,6 +5,9 @@ func (ms *MetricsSetup) RegisterDefaultMetrics() {
 	ms.RegisterMetricsCounter(MetricsFailed, nil)
 	ms.RegisterMetricsCounter(MetricsSkipped, nil)
 	ms.RegisterMetricsHistogram(MetricsDuration, nil)
+	ms.RegisterMetricsCounter(MetricsCacheHit, nil)
+	ms.RegisterMetricsCounter(MetricsCacheMiss, nil)
+	ms.RegisterMetricsCounter(MetricsQueriesCached, nil)
 }
 
 func (ms *MetricsSetup) RegisterGoMetrics() {

monitoring/structs.go

@@ -7,4 +7,8 @@ const (
 	MetricsSkipped       = "requests_skipped"
 	MetricsExecutedQuery = "executed_query"
 	MetricsTimedQuery    = "timed_query"
+
+	MetricsCacheHit      = "cache_hit"
+	MetricsCacheMiss     = "cache_miss"
+	MetricsQueriesCached = "cached_queries"
 )

ratelimit.go

@@ -27,7 +27,7 @@ var ratelimit_intervals = map[string]time.Duration{
 }
 
 func loadRatelimitConfig() error {
-	paths := []string{"/app/ratelimit.json", "./ratelimit.json", "./static/default-ratelimit.json"}
+	paths := []string{"/go/src/app/ratelimit.json", "./ratelimit.json", "./static/app/default-ratelimit.json"}
 
 	for _, path := range paths {
 		err := loadConfigFromPath(path)

server.go

@@ -16,6 +16,7 @@ import (
 
 // StartHTTPProxy starts the HTTP and points it to the GraphQL server.
 func StartHTTPProxy() {
+	cfg.Logger.Debug("Starting the HTTP proxy", nil)
 	server := fiber.New(fiber.Config{
 		DisableStartupMessage: true,
 		AppName:               fmt.Sprintf("GraphQL Monitoring Proxy - %s v%s", libpack_config.PKG_NAME, libpack_config.PKG_VERSION),
@@ -151,11 +152,13 @@ func processGraphQLRequest(c *fiber.Ctx) error {
 		queryCacheHash = calculateHash(c)
 
 		if cachedResponse := cacheLookup(queryCacheHash); cachedResponse != nil {
+			cfg.Monitoring.Increment(libpack_monitoring.MetricsCacheHit, nil)
 			cfg.Logger.Debug("Cache hit", map[string]interface{}{"hash": queryCacheHash, "user_id": extractedUserID, "request_uuid": c.Locals("request_uuid")})
 			c.Request().Header.Add("X-Cache-Hit", "true")
 			c.Send(cachedResponse)
 			wasCached = true
 		} else {
+			cfg.Monitoring.Increment(libpack_monitoring.MetricsCacheMiss, nil)
 			cfg.Logger.Debug("Cache miss", map[string]interface{}{"hash": queryCacheHash, "user_id": extractedUserID, "request_uuid": c.Locals("request_uuid")})
 			proxyAndCacheTheRequest(c, queryCacheHash, parsedResult.cacheTime, parsedResult.activeEndpoint)
 		}
@@ -181,6 +184,7 @@ func proxyAndCacheTheRequest(c *fiber.Ctx, queryCacheHash string, cacheTime int,
 		return
 	}
 	cfg.Cache.CacheClient.Set(queryCacheHash, c.Response().Body(), time.Duration(cacheTime)*time.Second)
+	cfg.Monitoring.Increment(libpack_monitoring.MetricsQueriesCached, nil)
 	c.Send(c.Response().Body())
 }
 

static/app/banned_users.json

@@ -0,0 +1 @@
+{}