add lru cache eviction metric

cmd/reflector.go

@@ -159,7 +159,7 @@ func wrapWithCache(s store.BlobStore) store.BlobStore {
 
 	if reflectorCmdMemCache > 0 {
 		wrapped = store.NewCachingStore(wrapped,
-			store.NewLRUStore(store.NewMemoryStore(), reflectorCmdMemCache))
+			store.NewLRUStore(store.NewMemStore(), reflectorCmdMemCache))
 	}
 
 	return wrapped

cmd/test.go

@@ -29,7 +29,7 @@ func init() {
 func testCmd(cmd *cobra.Command, args []string) {
 	log.Printf("reflector %s", meta.VersionString())
 
-	memStore := store.NewMemoryStore()
+	memStore := store.NewMemStore()
 
 	reflectorServer := reflector.NewServer(memStore)
 	reflectorServer.Timeout = 3 * time.Minute

internal/metrics/metrics.go

@@ -58,6 +58,7 @@ func (s *Server) Shutdown() {
 
 const (
 	ns             = "reflector"
+	subsystemCache = "cache"
 
 	labelDirection = "direction"
 	labelErrorType = "error_type"
@@ -65,7 +66,8 @@ const (
 	DirectionUpload   = "upload"   // to reflector
 	DirectionDownload = "download" // from reflector
 
-	MtrLabelSource = "source"
+	LabelCacheType = "cache_type"
+	LabelSource    = "source"
 
 	errConnReset         = "conn_reset"
 	errReadConnReset     = "read_conn_reset"
@@ -116,25 +118,35 @@ var (
 
 	CacheHitCount = promauto.NewCounter(prometheus.CounterOpts{
 		Namespace: ns,
-		Name:      "cache_hit_total",
+		Subsystem: subsystemCache,
+		Name:      "hit_total",
 		Help:      "Total number of blobs retrieved from the cache storage",
 	})
 	CacheMissCount = promauto.NewCounter(prometheus.CounterOpts{
 		Namespace: ns,
-		Name:      "cache_miss_total",
+		Subsystem: subsystemCache,
+		Name:      "miss_total",
 		Help:      "Total number of blobs retrieved from origin rather than cache storage",
 	})
 	CacheOriginRequestsCount = promauto.NewGauge(prometheus.GaugeOpts{
 		Namespace: ns,
-		Name:      "cache_origin_requests_total",
+		Subsystem: subsystemCache,
+		Name:      "origin_requests_total",
 		Help:      "How many Get requests are in flight from the cache to the origin",
 	})
 	// during thundering-herd situations, the metric below should be a lot smaller than the metric above
 	CacheWaitingRequestsCount = promauto.NewGauge(prometheus.GaugeOpts{
 		Namespace: ns,
-		Name:      "cache_waiting_requests_total",
+		Subsystem: subsystemCache,
+		Name:      "waiting_requests_total",
 		Help:      "How many cache requests are waiting for an in-flight origin request",
 	})
+	CacheLRUEvictCount = promauto.NewCounterVec(prometheus.CounterOpts{
+		Namespace: ns,
+		Subsystem: subsystemCache,
+		Name:      "evict_total",
+		Help:      "Count of blobs evicted from cache",
+	}, []string{LabelCacheType})
 
 	BlobUploadCount = promauto.NewCounter(prometheus.CounterOpts{
 		Namespace: ns,
@@ -151,7 +163,7 @@ var (
 		Namespace: ns,
 		Name:      "speed_mbps",
 		Help:      "Speed of blob retrieval",
-	}, []string{MtrLabelSource})
+	}, []string{LabelSource})
 
 	MtrInBytesTcp = promauto.NewCounter(prometheus.CounterOpts{
 		Namespace: ns,

peer/http3/store.go

@@ -55,6 +55,8 @@ func (p *Store) getClient() (*Client, error) {
 	return c, errors.Prefix("connection error", err)
 }
 
+func (p *Store) Name() string { return "http3" }
+
 // Has asks the peer if they have a hash
 func (p *Store) Has(hash string) (bool, error) {
 	c, err := p.getClient()

peer/server_test.go

@@ -34,7 +34,7 @@ var availabilityRequests = []pair{
 }
 
 func getServer(t *testing.T, withBlobs bool) *Server {
-	st := store.NewMemoryStore()
+	st := store.NewMemStore()
 	if withBlobs {
 		for k, v := range blobs {
 			err := st.Put(k, v)

peer/store.go

@@ -30,6 +30,8 @@ func (p *Store) getClient() (*Client, error) {
 	return c, errors.Prefix("connection error", err)
 }
 
+func (p *Store) Name() string { return "peer" }
+
 // Has asks the peer if they have a hash
 func (p *Store) Has(hash string) (bool, error) {
 	c, err := p.getClient()

reflector/server_test.go

@@ -22,7 +22,7 @@ func startServerOnRandomPort(t *testing.T) (*Server, int) {
 		t.Fatal(err)
 	}
 
-	srv := NewServer(store.NewMemoryStore())
+	srv := NewServer(store.NewMemStore())
 	err = srv.Start("127.0.0.1:" + strconv.Itoa(port))
 	if err != nil {
 		t.Fatal(err)
@@ -119,7 +119,7 @@ func TestServer_Timeout(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	srv := NewServer(store.NewMemoryStore())
+	srv := NewServer(store.NewMemStore())
 	srv.Timeout = testTimeout
 	err = srv.Start("127.0.0.1:" + strconv.Itoa(port))
 	if err != nil {
@@ -161,7 +161,7 @@ func TestServer_Timeout(t *testing.T) {
 //}
 
 type mockPartialStore struct {
-	*store.MemoryStore
+	*store.MemStore
 	missing []string
 }
 
@@ -181,7 +181,7 @@ func TestServer_PartialUpload(t *testing.T) {
 		missing[i] = bits.Rand().String()
 	}
 
-	st := store.BlobStore(&mockPartialStore{MemoryStore: store.NewMemoryStore(), missing: missing})
+	st := store.BlobStore(&mockPartialStore{MemStore: store.NewMemStore(), missing: missing})
 	if _, ok := st.(neededBlobChecker); !ok {
 		t.Fatal("mock does not implement the relevant interface")
 	}

store/caching.go

@@ -25,6 +25,11 @@ func NewCachingStore(origin, cache BlobStore) *CachingStore {
 	return &CachingStore{origin: origin, cache: cache, sf: new(singleflight.Group)}
 }
 
+const nameCaching = "caching"
+
+// Name is the cache type name
+func (c *CachingStore) Name() string { return nameCaching }
+
 // Has checks the cache and then the origin for a hash. It returns true if either store has it.
 func (c *CachingStore) Has(hash string) (bool, error) {
 	has, err := c.cache.Has(hash)
@@ -42,7 +47,7 @@ func (c *CachingStore) Get(hash string) (stream.Blob, error) {
 	if err == nil || !errors.Is(err, ErrBlobNotFound) {
 		metrics.CacheHitCount.Inc()
 		rate := float64(len(blob)) / 1024 / 1024 / time.Since(start).Seconds()
-		metrics.RetrieverSpeed.With(map[string]string{metrics.MtrLabelSource: "cache"}).Set(rate)
+		metrics.RetrieverSpeed.With(map[string]string{metrics.LabelSource: "cache"}).Set(rate)
 		return blob, err
 	}
 
@@ -66,7 +71,7 @@ func (c *CachingStore) getFromOrigin(hash string) (stream.Blob, error) {
 		}
 
 		rate := float64(len(blob)) / 1024 / 1024 / time.Since(start).Seconds()
-		metrics.RetrieverSpeed.With(map[string]string{metrics.MtrLabelSource: "origin"}).Set(rate)
+		metrics.RetrieverSpeed.With(map[string]string{metrics.LabelSource: "origin"}).Set(rate)
 
 		err = c.cache.Put(hash, blob)
 		return blob, err

store/caching_test.go

@@ -9,9 +9,9 @@ import (
 	"github.com/lbryio/lbry.go/v2/stream"
 )
 
-func TestCachingBlobStore_Put(t *testing.T) {
+func TestCachingStore_Put(t *testing.T) {
-	origin := NewMemoryStore()
+	origin := NewMemStore()
-	cache := NewMemoryStore()
+	cache := NewMemStore()
 	s := NewCachingStore(origin, cache)
 
 	b := []byte("this is a blob of stuff")
@@ -39,9 +39,9 @@ func TestCachingBlobStore_Put(t *testing.T) {
 	}
 }
 
-func TestCachingBlobStore_CacheMiss(t *testing.T) {
+func TestCachingStore_CacheMiss(t *testing.T) {
-	origin := NewMemoryStore()
+	origin := NewMemStore()
-	cache := NewMemoryStore()
+	cache := NewMemStore()
 	s := NewCachingStore(origin, cache)
 
 	b := []byte("this is a blob of stuff")
@@ -76,10 +76,10 @@ func TestCachingBlobStore_CacheMiss(t *testing.T) {
 	}
 }
 
-func TestCachingBlobStore_ThunderingHerd(t *testing.T) {
+func TestCachingStore_ThunderingHerd(t *testing.T) {
 	storeDelay := 100 * time.Millisecond
 	origin := NewSlowBlobStore(storeDelay)
-	cache := NewMemoryStore()
+	cache := NewMemStore()
 	s := NewCachingStore(origin, cache)
 
 	b := []byte("this is a blob of stuff")
@@ -129,16 +129,19 @@ func TestCachingBlobStore_ThunderingHerd(t *testing.T) {
 
 // SlowBlobStore adds a delay to each request
 type SlowBlobStore struct {
-	mem   *MemoryStore
+	mem   *MemStore
 	delay time.Duration
 }
 
 func NewSlowBlobStore(delay time.Duration) *SlowBlobStore {
 	return &SlowBlobStore{
-		mem:   NewMemoryStore(),
+		mem:   NewMemStore(),
 		delay: delay,
 	}
 }
+func (s *SlowBlobStore) Name() string {
+	return "slow"
+}
 
 func (s *SlowBlobStore) Has(hash string) (bool, error) {
 	time.Sleep(s.delay)

store/cloudfront.go

@@ -34,6 +34,11 @@ func NewCloudFrontStore(s3 *S3Store, cfEndpoint string) *CloudFrontStore {
 	}
 }
 
+const nameCloudFront = "cloudfront"
+
+// Name is the cache type name
+func (c *CloudFrontStore) Name() string { return nameCloudFront }
+
 // Has checks if the hash is in the store.
 func (c *CloudFrontStore) Has(hash string) (bool, error) {
 	status, body, err := c.cfRequest(http.MethodHead, hash)

store/dbbacked.go

@@ -25,6 +25,11 @@ func NewDBBackedStore(blobs BlobStore, db *db.SQL) *DBBackedStore {
 	return &DBBackedStore{blobs: blobs, db: db}
 }
 
+const nameDBBacked = "db-backed"
+
+// Name is the cache type name
+func (d *DBBackedStore) Name() string { return nameDBBacked }
+
 // Has returns true if the blob is in the store
 func (d *DBBackedStore) Has(hash string) (bool, error) {
 	return d.db.HasBlob(hash)

store/disk.go

@@ -35,34 +35,10 @@ func NewDiskStore(dir string, prefixLength int) *DiskStore {
 	}
 }
 
-func (d *DiskStore) dir(hash string) string {
+const nameDisk = "disk"
-	if d.prefixLength <= 0 || len(hash) < d.prefixLength {
-		return d.blobDir
-	}
-	return path.Join(d.blobDir, hash[:d.prefixLength])
-}
 
-func (d *DiskStore) path(hash string) string {
+// Name is the cache type name
-	return path.Join(d.dir(hash), hash)
+func (d *DiskStore) Name() string { return nameDisk }
-}
-
-func (d *DiskStore) ensureDirExists(dir string) error {
-	return errors.Err(d.fs.MkdirAll(dir, 0755))
-}
-
-func (d *DiskStore) initOnce() error {
-	if d.initialized {
-		return nil
-	}
-
-	err := d.ensureDirExists(d.blobDir)
-	if err != nil {
-		return err
-	}
-
-	d.initialized = true
-	return nil
-}
 
 // Has returns T/F or Error if it the blob stored already. It will error with any IO disk error.
 func (d *DiskStore) Has(hash string) (bool, error) {
@@ -166,3 +142,32 @@ func (d *DiskStore) list() ([]string, error) {
 
 	return existing, nil
 }
+
+func (d *DiskStore) dir(hash string) string {
+	if d.prefixLength <= 0 || len(hash) < d.prefixLength {
+		return d.blobDir
+	}
+	return path.Join(d.blobDir, hash[:d.prefixLength])
+}
+
+func (d *DiskStore) path(hash string) string {
+	return path.Join(d.dir(hash), hash)
+}
+
+func (d *DiskStore) ensureDirExists(dir string) error {
+	return errors.Err(d.fs.MkdirAll(dir, 0755))
+}
+
+func (d *DiskStore) initOnce() error {
+	if d.initialized {
+		return nil
+	}
+
+	err := d.ensureDirExists(d.blobDir)
+	if err != nil {
+		return err
+	}
+
+	d.initialized = true
+	return nil
+}

store/lru.go

@@ -3,6 +3,7 @@ package store
 import (
 	"github.com/lbryio/lbry.go/v2/extras/errors"
 	"github.com/lbryio/lbry.go/v2/stream"
+	"github.com/lbryio/reflector.go/internal/metrics"
 
 	golru "github.com/hashicorp/golang-lru"
 )
@@ -18,6 +19,7 @@ type LRUStore struct {
 // NewLRUStore initialize a new LRUStore
 func NewLRUStore(store BlobStore, maxItems int) *LRUStore {
 	lru, err := golru.NewWithEvict(maxItems, func(key interface{}, value interface{}) {
+		metrics.CacheLRUEvictCount.WithLabelValues(store.Name()).Inc()
 		_ = store.Delete(key.(string)) // TODO: log this error. may happen if underlying entry is gone but cache entry still there
 	})
 	if err != nil {
@@ -39,6 +41,11 @@ func NewLRUStore(store BlobStore, maxItems int) *LRUStore {
 	return l
 }
 
+const nameLRU = "lru"
+
+// Name is the cache type name
+func (l *LRUStore) Name() string { return nameLRU }
+
 // Has returns whether the blob is in the store, without updating the recent-ness.
 func (l *LRUStore) Has(hash string) (bool, error) {
 	return l.lru.Contains(hash), nil

store/lru_test.go

@@ -14,7 +14,7 @@ import (
 
 const cacheMaxBlobs = 3
 
-func testLRUStore() (*LRUStore, *DiskStore) {
+func getTestLRUStore() (*LRUStore, *DiskStore) {
 	d := NewDiskStore("/", 2)
 	d.fs = afero.NewMemMapFs()
 	return NewLRUStore(d, 3), d
@@ -42,7 +42,7 @@ func countOnDisk(t *testing.T, disk *DiskStore) int {
 }
 
 func TestLRUStore_Eviction(t *testing.T) {
-	lru, disk := testLRUStore()
+	lru, disk := getTestLRUStore()
 	b := []byte("x")
 	err := lru.Put("one", b)
 	require.NoError(t, err)
@@ -98,7 +98,7 @@ func TestLRUStore_Eviction(t *testing.T) {
 }
 
 func TestLRUStore_UnderlyingBlobMissing(t *testing.T) {
-	lru, disk := testLRUStore()
+	lru, disk := getTestLRUStore()
 	hash := "hash"
 	b := []byte("this is a blob of stuff")
 	err := lru.Put(hash, b)

store/memory.go

@@ -5,25 +5,30 @@ import (
 	"github.com/lbryio/lbry.go/v2/stream"
 )
 
-// MemoryStore is an in memory only blob store with no persistence.
+// MemStore is an in memory only blob store with no persistence.
-type MemoryStore struct {
+type MemStore struct {
 	blobs map[string]stream.Blob
 }
 
-func NewMemoryStore() *MemoryStore {
+func NewMemStore() *MemStore {
-	return &MemoryStore{
+	return &MemStore{
 		blobs: make(map[string]stream.Blob),
 	}
 }
 
+const nameMem = "mem"
+
+// Name is the cache type name
+func (m *MemStore) Name() string { return nameMem }
+
 // Has returns T/F if the blob is currently stored. It will never error.
-func (m *MemoryStore) Has(hash string) (bool, error) {
+func (m *MemStore) Has(hash string) (bool, error) {
 	_, ok := m.blobs[hash]
 	return ok, nil
 }
 
 // Get returns the blob byte slice if present and errors if the blob is not found.
-func (m *MemoryStore) Get(hash string) (stream.Blob, error) {
+func (m *MemStore) Get(hash string) (stream.Blob, error) {
 	blob, ok := m.blobs[hash]
 	if !ok {
 		return nil, errors.Err(ErrBlobNotFound)
@@ -32,23 +37,23 @@ func (m *MemoryStore) Get(hash string) (stream.Blob, error) {
 }
 
 // Put stores the blob in memory
-func (m *MemoryStore) Put(hash string, blob stream.Blob) error {
+func (m *MemStore) Put(hash string, blob stream.Blob) error {
 	m.blobs[hash] = blob
 	return nil
 }
 
 // PutSD stores the sd blob in memory
-func (m *MemoryStore) PutSD(hash string, blob stream.Blob) error {
+func (m *MemStore) PutSD(hash string, blob stream.Blob) error {
 	return m.Put(hash, blob)
 }
 
 // Delete deletes the blob from the store
-func (m *MemoryStore) Delete(hash string) error {
+func (m *MemStore) Delete(hash string) error {
 	delete(m.blobs, hash)
 	return nil
 }
 
 // Debug returns the blobs in memory. It's useful for testing and debugging.
-func (m *MemoryStore) Debug() map[string]stream.Blob {
+func (m *MemStore) Debug() map[string]stream.Blob {
 	return m.blobs
 }

store/memory_test.go

@@ -7,8 +7,8 @@ import (
 	"github.com/lbryio/lbry.go/v2/extras/errors"
 )
 
-func TestMemoryBlobStore_Put(t *testing.T) {
+func TestMemStore_Put(t *testing.T) {
-	s := NewMemoryStore()
+	s := NewMemStore()
 	blob := []byte("abcdefg")
 	err := s.Put("abc", blob)
 	if err != nil {
@@ -16,8 +16,8 @@ func TestMemoryBlobStore_Put(t *testing.T) {
 	}
 }
 
-func TestMemoryBlobStore_Get(t *testing.T) {
+func TestMemStore_Get(t *testing.T) {
-	s := NewMemoryStore()
+	s := NewMemStore()
 	hash := "abc"
 	blob := []byte("abcdefg")
 	err := s.Put(hash, blob)

store/s3.go

@@ -38,22 +38,10 @@ func NewS3Store(awsID, awsSecret, region, bucket string) *S3Store {
 	}
 }
 
-func (s *S3Store) initOnce() error {
+const nameS3 = "s3"
-	if s.session != nil {
-		return nil
-	}
 
-	sess, err := session.NewSession(&aws.Config{
+// Name is the cache type name
-		Credentials: credentials.NewStaticCredentials(s.awsID, s.awsSecret, ""),
+func (s *S3Store) Name() string { return nameS3 }
-		Region:      aws.String(s.region),
-	})
-	if err != nil {
-		return err
-	}
-
-	s.session = sess
-	return nil
-}
 
 // Has returns T/F or Error ( from S3 ) if the store contains the blob.
 func (s *S3Store) Has(hash string) (bool, error) {
@@ -153,3 +141,20 @@ func (s *S3Store) Delete(hash string) error {
 
 	return err
 }
+
+func (s *S3Store) initOnce() error {
+	if s.session != nil {
+		return nil
+	}
+
+	sess, err := session.NewSession(&aws.Config{
+		Credentials: credentials.NewStaticCredentials(s.awsID, s.awsSecret, ""),
+		Region:      aws.String(s.region),
+	})
+	if err != nil {
+		return err
+	}
+
+	s.session = sess
+	return nil
+}

store/store.go

@@ -7,6 +7,8 @@ import (
 
 // BlobStore is an interface for handling blob storage.
 type BlobStore interface {
+	// Name of blob store (useful for metrics)
+	Name() string
 	// Does blob exist in the store
 	Has(hash string) (bool, error)
 	// Get the blob from the store