chore(remotestorage): Add prometheus metrics for remote storage kind

Signed-off-by: Bartłomiej Święcki <[email protected]>

Author: Bartłomiej Święcki

embedded/appendable/remoteapp/remote_app_test.go

@@ -404,6 +404,10 @@ type remoteStorageMockingWrapper struct {
 	fnListEntries func(ctx context.Context, path string, next func() (entries []remotestorage.EntryInfo, subPaths []string, err error)) (entries []remotestorage.EntryInfo, subPaths []string, err error)
 }
 
+func (r *remoteStorageMockingWrapper) Kind() string {
+	return r.wrapped.Kind()
+}
+
 func (r *remoteStorageMockingWrapper) String() string {
 	return r.wrapped.String()
 }

embedded/remotestorage/memory/memory.go

@@ -49,6 +49,10 @@ func Open() *Storage {
 	}
 }
 
+func (r *Storage) Kind() string {
+	return "memory"
+}
+
 func (r *Storage) String() string {
 	return fmt.Sprintf("memory(%p):", r)
 }

embedded/remotestorage/memory/memory_test.go

@@ -169,6 +169,7 @@ func TestRemoteStorageAPIMemoryPutError(t *testing.T) {
 func TestRemoteStorageName(t *testing.T) {
 	storage := Open()
 	require.Contains(t, storage.String(), "memory")
+	require.Equal(t, "memory", storage.Kind())
 }
 
 func TestRemoteStorageGetInvalidParams(t *testing.T) {

embedded/remotestorage/remote_storage.go

@@ -31,6 +31,9 @@ type EntryInfo struct {
 }
 
 type Storage interface {
+	// Kind returns the kind of remote storage, e.g. `s3`
+	Kind() string
+
 	// String returns a human-readable representation of the storage
 	String() string
 

embedded/remotestorage/s3/s3.go

@@ -120,6 +120,10 @@ func Open(
 	}, nil
 }
 
+func (s *Storage) Kind() string {
+	return "s3"
+}
+
 func (s *Storage) String() string {
 	url, err := s.originalRequestURL("")
 	if err != nil {

embedded/remotestorage/s3/s3_test.go

@@ -41,6 +41,7 @@ func TestOpen(t *testing.T) {
 	)
 	require.NoError(t, err)
 	require.NotNil(t, s)
+	require.Equal(t, "s3", s.Kind())
 	require.Equal(t, "s3:http://localhost:9000/immudb/prefix/", s.String())
 }
 

pkg/server/metrics.go

@@ -55,6 +55,8 @@ type MetricsCollection struct {
 
 	RPCsPerClientCounters        *prometheus.CounterVec
 	LastMessageAtPerClientGauges *prometheus.GaugeVec
+
+	RemoteStorageKind *prometheus.GaugeVec
 }
 
 var metricsNamespace = "immudb"
@@ -141,6 +143,14 @@ var Metrics = MetricsCollection{
 		},
 		[]string{"ip"},
 	),
+	RemoteStorageKind: promauto.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Namespace: metricsNamespace,
+			Name:      "remote_storage_kind",
+			Help:      "Set to 1 for remote storage kind for given database",
+		},
+		[]string{"db", "kind"},
+	),
 }
 
 // StartMetrics listens and servers the HTTP metrics server in a new goroutine.

pkg/server/remote_storage.go

@@ -152,6 +152,13 @@ func (s *ImmuServer) storeOptionsForDB(name string, remoteStorage remotestorage.
 		}).
 			WithFileSize(1 << 20).       // Reduce file size for better cache granularity
 			WithCompactionDisabled(true) // Disable index compaction
+
+		Metrics.RemoteStorageKind.WithLabelValues(name, remoteStorage.Kind()).Set(1)
+
+	} else {
+
+		// No remote storage
+		Metrics.RemoteStorageKind.WithLabelValues(name, "none").Set(1)
 	}
 
 	return stOpts

pkg/server/remote_storage_test.go

@@ -43,6 +43,10 @@ type remoteStorageMockingWrapper struct {
 	fnListEntries func(ctx context.Context, path string, next func() (entries []remotestorage.EntryInfo, subPaths []string, err error)) (entries []remotestorage.EntryInfo, subPaths []string, err error)
 }
 
+func (r *remoteStorageMockingWrapper) Kind() string {
+	return r.wrapped.Kind()
+}
+
 func (r *remoteStorageMockingWrapper) String() string {
 	return r.wrapped.String()
 }