From 9eca875ae09a991a04ba7e7aadbed9c69d1da622 Mon Sep 17 00:00:00 2001
From: Bartek Nowotarski <bartek@nowotarski.info>
Date: Wed, 19 Sep 2018 16:47:36 +0200
Subject: [PATCH] Feature flag to disable asset stats (#668)

---
 services/horizon/db.go                        | 12 +++---
 .../horizon/internal/actions_assets_test.go   | 20 ++++++++-
 services/horizon/internal/config.go           |  7 ++-
 .../horizon/internal/ingest/ingestion_test.go | 43 +++++++++++++++++--
 services/horizon/internal/ingest/main.go      | 28 ++++++------
 services/horizon/internal/ingest/main_test.go | 13 +++---
 services/horizon/internal/ingest/session.go   |  5 ++-
 .../horizon/internal/ingest/session_test.go   |  8 ++--
 .../horizon/internal/ingest/system_test.go    |  6 +--
 services/horizon/internal/init_ingester.go    |  3 ++
 services/horizon/internal/init_web.go         |  7 ++-
 services/horizon/main.go                      |  2 +
 12 files changed, 113 insertions(+), 41 deletions(-)

diff --git a/services/horizon/db.go b/services/horizon/db.go
index 6f2f726b9d..8cfb265a29 100644
--- a/services/horizon/db.go
+++ b/services/horizon/db.go
@@ -28,7 +28,7 @@ var dbBackfillCmd = &cobra.Command{
 		initConfig()
 		hlog.DefaultLogger.Logger.Level = config.LogLevel
 
-		i := ingestSystem()
+		i := ingestSystem(ingest.Config{})
 		i.SkipCursorUpdate = true
 		parsed, err := strconv.ParseUint(args[0], 10, 32)
 		if err != nil {
@@ -49,7 +49,7 @@ var dbClearCmd = &cobra.Command{
 		initConfig()
 		hlog.DefaultLogger.Logger.Level = config.LogLevel
 
-		i := ingestSystem()
+		i := ingestSystem(ingest.Config{})
 		err := i.ClearAll()
 		if err != nil {
 			hlog.Error(err)
@@ -138,7 +138,7 @@ var dbRebaseCmd = &cobra.Command{
 		initConfig()
 		hlog.DefaultLogger.Logger.Level = config.LogLevel
 
-		i := ingestSystem()
+		i := ingestSystem(ingest.Config{})
 		i.SkipCursorUpdate = true
 
 		err := i.RebaseHistory()
@@ -156,7 +156,7 @@ var dbReingestCmd = &cobra.Command{
 		initConfig()
 		hlog.DefaultLogger.Logger.Level = config.LogLevel
 
-		i := ingestSystem()
+		i := ingestSystem(ingest.Config{})
 		i.SkipCursorUpdate = true
 		logStatus := func(stage string) {
 			count := i.Metrics.IngestLedgerTimer.Count()
@@ -207,7 +207,7 @@ func init() {
 	dbCmd.AddCommand(dbRebaseCmd)
 }
 
-func ingestSystem() *ingest.System {
+func ingestSystem(ingestConfig ingest.Config) *ingest.System {
 	hdb, err := db.Open("postgres", config.DatabaseURL)
 	if err != nil {
 		log.Fatal(err)
@@ -223,7 +223,7 @@ func ingestSystem() *ingest.System {
 		log.Fatal("network-passphrase is blank: reingestion requires manually setting passphrase")
 	}
 
-	i := ingest.New(passphrase, config.StellarCoreURL, cdb, hdb)
+	i := ingest.New(passphrase, config.StellarCoreURL, cdb, hdb, ingestConfig)
 	return i
 }
 
diff --git a/services/horizon/internal/actions_assets_test.go b/services/horizon/internal/actions_assets_test.go
index 2da813799c..244ecbb84c 100644
--- a/services/horizon/internal/actions_assets_test.go
+++ b/services/horizon/internal/actions_assets_test.go
@@ -3,8 +3,9 @@ package horizon
 import (
 	"testing"
 
-	"github.com/stellar/go/protocols/horizon/base"
 	"github.com/stellar/go/protocols/horizon"
+	"github.com/stellar/go/protocols/horizon/base"
+	"github.com/stellar/go/services/horizon/internal/test"
 	"github.com/stellar/go/support/render/hal"
 )
 
@@ -271,3 +272,20 @@ func TestInvalidAssetIssuer(t *testing.T) {
 	w = ht.Get("/assets?asset_issuer=invalid")
 	ht.Assert.Equal(400, w.Code)
 }
+
+func TestAssetStatsDisabled(t *testing.T) {
+	ht := StartHTTPTest(t, "ingest_asset_stats")
+	defer ht.Finish()
+
+	// Ugly but saves us time needed to change each `StartHTTPTest` occurence.
+	appConfig := NewTestConfig()
+	appConfig.DisableAssetStats = true
+
+	var err error
+	ht.App, err = NewApp(appConfig)
+	ht.Assert.Nil(err)
+	ht.RH = test.NewRequestHelper(ht.App.web.router)
+
+	w := ht.Get("/assets?asset_issuer=GC23QF2HUE52AMXUFUH3AYJAXXGXXV2VHXYYR6EYXETPKDXZSAW67XO4")
+	ht.Assert.Equal(404, w.Code)
+}
diff --git a/services/horizon/internal/config.go b/services/horizon/internal/config.go
index 1a49747ab7..0a1f069136 100644
--- a/services/horizon/internal/config.go
+++ b/services/horizon/internal/config.go
@@ -33,13 +33,16 @@ type Config struct {
 	// determining a "retention duration", each ledger roughly corresponds to 10
 	// seconds of real time.
 	HistoryRetentionCount uint
-
 	// StaleThreshold represents the number of ledgers a history database may be
 	// out-of-date by before horizon begins to respond with an error to history
 	// requests.
 	StaleThreshold uint
-
 	// SkipCursorUpdate causes the ingestor to skip reporting the "last imported
 	// ledger" state to stellar-core.
 	SkipCursorUpdate bool
+	// DisableAssetStats is a feature flag that determines whether to calculate
+	// asset stats during the ingestion and expose `/assets` endpoint.
+	// Disabling it will save CPU when ingesting ledgers full of many different
+	// assets related operations.
+	DisableAssetStats bool
 }
diff --git a/services/horizon/internal/ingest/ingestion_test.go b/services/horizon/internal/ingest/ingestion_test.go
index 912295aaf7..a8fbfb03bd 100644
--- a/services/horizon/internal/ingest/ingestion_test.go
+++ b/services/horizon/internal/ingest/ingestion_test.go
@@ -55,7 +55,7 @@ func TestAssetIngest(t *testing.T) {
 
 	tt := test.Start(t).ScenarioWithoutHorizon("kahuna")
 	defer tt.Finish()
-	s := ingest(tt)
+	s := ingest(tt, false)
 	tt.Require.NoError(s.Err)
 	q := history.Q{Session: s.Ingestion.DB}
 
@@ -75,7 +75,7 @@ func TestAssetIngest(t *testing.T) {
 func TestAssetStatsIngest(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("ingest_asset_stats")
 	defer tt.Finish()
-	s := ingest(tt)
+	s := ingest(tt, false)
 	tt.Require.NoError(s.Err)
 	q := history.Q{Session: s.Ingestion.DB}
 
@@ -139,12 +139,49 @@ func TestAssetStatsIngest(t *testing.T) {
 	}, assetStats[2])
 }
 
+func TestAssetStatsDisabledIngest(t *testing.T) {
+	tt := test.Start(t).ScenarioWithoutHorizon("ingest_asset_stats")
+	defer tt.Finish()
+	s := ingest(tt, true)
+	tt.Require.NoError(s.Err)
+	q := history.Q{Session: s.Ingestion.DB}
+
+	type AssetStatResult struct {
+		Type        string `db:"asset_type"`
+		Code        string `db:"asset_code"`
+		Issuer      string `db:"asset_issuer"`
+		Amount      int64  `db:"amount"`
+		NumAccounts int32  `db:"num_accounts"`
+		Flags       int8   `db:"flags"`
+		Toml        string `db:"toml"`
+	}
+	assetStats := []AssetStatResult{}
+	err := q.Select(
+		&assetStats,
+		sq.
+			Select(
+				"hist.asset_type",
+				"hist.asset_code",
+				"hist.asset_issuer",
+				"stats.amount",
+				"stats.num_accounts",
+				"stats.flags",
+				"stats.toml",
+			).
+			From("history_assets hist").
+			Join("asset_stats stats ON hist.id = stats.id").
+			OrderBy("hist.asset_code ASC", "hist.asset_issuer ASC"),
+	)
+	tt.Require.NoError(err)
+	tt.Assert.Equal(0, len(assetStats))
+}
+
 func TestTradeIngestTimestamp(t *testing.T) {
 	//ingest trade scenario and verify that the trade timestamp
 	//matches the appropriate ledger's timestamp
 	tt := test.Start(t).ScenarioWithoutHorizon("trades")
 	defer tt.Finish()
-	s := ingest(tt)
+	s := ingest(tt, false)
 	q := history.Q{Session: s.Ingestion.DB}
 
 	var ledgers []history.Ledger
diff --git a/services/horizon/internal/ingest/main.go b/services/horizon/internal/ingest/main.go
index 03cffd4999..64bb4adbd7 100644
--- a/services/horizon/internal/ingest/main.go
+++ b/services/horizon/internal/ingest/main.go
@@ -66,6 +66,13 @@ type Cursor struct {
 	data *LedgerBundle
 }
 
+// Config allows passing some configuration values to System and Session.
+type Config struct {
+	// DisableAssetStats is a feature flag that determines whether to calculate
+	// asset stats in this ingestion system.
+	DisableAssetStats bool
+}
+
 // EffectIngestion is a helper struct to smooth the ingestion of effects.  this
 // struct will track what the correct operation to use and order to use when
 // adding effects into an ingestion.
@@ -88,27 +95,23 @@ type LedgerBundle struct {
 
 // System represents the data ingestion subsystem of horizon.
 type System struct {
+	// Config allows passing some configuration values to System.
+	Config Config
 	// HorizonDB is the connection to the horizon database that ingested data will
 	// be written to.
 	HorizonDB *db.Session
-
 	// CoreDB is the stellar-core db that data is ingested from.
-	CoreDB *db.Session
-
+	CoreDB  *db.Session
 	Metrics IngesterMetrics
-
 	// Network is the passphrase for the network being imported
 	Network string
-
 	// StellarCoreURL is the http endpoint of the stellar-core that data is being
 	// ingested from.
 	StellarCoreURL string
-
 	// SkipCursorUpdate causes the ingestor to skip
 	// reporting the "last imported ledger" cursor to
 	// stellar-core
 	SkipCursorUpdate bool
-
 	// HistoryRetentionCount is the desired minimum number of ledgers to
 	// keep in the history database, working backwards from the latest core
 	// ledger.  0 represents "all ledgers".
@@ -150,24 +153,22 @@ type Ingestion struct {
 // Session represents a single attempt at ingesting data into the history
 // database.
 type Session struct {
+	// Config allows passing some configuration values to System.
+	Config    Config
 	Cursor    *Cursor
 	Ingestion *Ingestion
 	// Network is the passphrase for the network being imported
 	Network string
-
 	// StellarCoreURL is the http endpoint of the stellar-core that data is being
 	// ingested from.
 	StellarCoreURL string
-
 	// ClearExisting causes the session to clear existing data from the horizon db
 	// when the session is run.
 	ClearExisting bool
-
 	// SkipCursorUpdate causes the session to skip
 	// reporting the "last imported ledger" cursor to
 	// stellar-core
 	SkipCursorUpdate bool
-
 	// Metrics is a reference to where the session should record its metric information
 	Metrics *IngesterMetrics
 
@@ -177,7 +178,6 @@ type Session struct {
 
 	// Err is the error that caused this session to fail, if any.
 	Err error
-
 	// Ingested is the number of ledgers that were successfully ingested during
 	// this session.
 	Ingested int
@@ -185,8 +185,9 @@ type Session struct {
 
 // New initializes the ingester, causing it to begin polling the stellar-core
 // database for now ledgers and ingesting data into the horizon database.
-func New(network string, coreURL string, core, horizon *db.Session) *System {
+func New(network string, coreURL string, core, horizon *db.Session, config Config) *System {
 	i := &System{
+		Config:         config,
 		Network:        network,
 		StellarCoreURL: coreURL,
 		HorizonDB:      horizon,
@@ -215,6 +216,7 @@ func NewSession(i *System) *Session {
 	hdb := i.HorizonDB.Clone()
 
 	return &Session{
+		Config: i.Config,
 		Ingestion: &Ingestion{
 			DB: hdb,
 		},
diff --git a/services/horizon/internal/ingest/main_test.go b/services/horizon/internal/ingest/main_test.go
index 63c34f3efa..c8d62be5a1 100644
--- a/services/horizon/internal/ingest/main_test.go
+++ b/services/horizon/internal/ingest/main_test.go
@@ -13,7 +13,7 @@ func TestIngest_Kahuna1(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("kahuna")
 	defer tt.Finish()
 
-	s := ingest(tt)
+	s := ingest(tt, false)
 
 	tt.Require.NoError(s.Err)
 	tt.Assert.Equal(62, s.Ingested)
@@ -34,7 +34,7 @@ func TestIngest_Kahuna2(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("kahuna-2")
 	defer tt.Finish()
 
-	s := ingest(tt)
+	s := ingest(tt, false)
 
 	tt.Require.NoError(s.Err)
 	tt.Assert.Equal(6, s.Ingested)
@@ -52,7 +52,7 @@ func TestIngest_Kahuna2(t *testing.T) {
 func TestTick(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("base")
 	defer tt.Finish()
-	sys := sys(tt)
+	sys := sys(tt, false)
 
 	// ingest by tick
 	s := sys.Tick()
@@ -65,8 +65,8 @@ func TestTick(t *testing.T) {
 	tt.Require.NoError(s.Err)
 }
 
-func ingest(tt *test.T) *Session {
-	sys := sys(tt)
+func ingest(tt *test.T, disableAssetStats bool) *Session {
+	sys := sys(tt, disableAssetStats)
 	s := NewSession(sys)
 	s.Cursor = NewCursor(1, ledger.CurrentState().CoreLatest, sys)
 	s.Run()
@@ -74,11 +74,12 @@ func ingest(tt *test.T) *Session {
 	return s
 }
 
-func sys(tt *test.T) *System {
+func sys(tt *test.T, disableAssetStats bool) *System {
 	return New(
 		network.TestNetworkPassphrase,
 		"",
 		tt.CoreSession(),
 		tt.HorizonSession(),
+		Config{DisableAssetStats: disableAssetStats},
 	)
 }
diff --git a/services/horizon/internal/ingest/session.go b/services/horizon/internal/ingest/session.go
index 952fb6943c..93e9ccf402 100644
--- a/services/horizon/internal/ingest/session.go
+++ b/services/horizon/internal/ingest/session.go
@@ -46,7 +46,10 @@ func (is *Session) Run() {
 			break
 		}
 	}
-	is.Cursor.AssetsModified.UpdateAssetStats(is)
+
+	if !is.Config.DisableAssetStats {
+		is.Cursor.AssetsModified.UpdateAssetStats(is)
+	}
 
 	if is.Err != nil {
 		is.Ingestion.Rollback()
diff --git a/services/horizon/internal/ingest/session_test.go b/services/horizon/internal/ingest/session_test.go
index 192a89fd42..5684d9a668 100644
--- a/services/horizon/internal/ingest/session_test.go
+++ b/services/horizon/internal/ingest/session_test.go
@@ -13,7 +13,7 @@ func Test_ingestSignerEffects(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("set_options")
 	defer tt.Finish()
 
-	s := ingest(tt)
+	s := ingest(tt, false)
 	tt.Require.NoError(s.Err)
 
 	q := &history.Q{Session: tt.HorizonSession()}
@@ -33,7 +33,7 @@ func Test_ingestOperationEffects(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("set_options")
 	defer tt.Finish()
 
-	s := ingest(tt)
+	s := ingest(tt, false)
 	tt.Require.NoError(s.Err)
 
 	q := &history.Q{Session: tt.HorizonSession()}
@@ -49,7 +49,7 @@ func Test_ingestOperationEffects(t *testing.T) {
 
 	// HACK(scott): switch to kahuna recipe mid-stream.  We need to integrate our test scenario loader to be compatible with go subtests/
 	tt.ScenarioWithoutHorizon("kahuna")
-	s = ingest(tt)
+	s = ingest(tt, false)
 	tt.Require.NoError(s.Err)
 	pq, err := db2.NewPageQuery("", "asc", 200)
 	tt.Require.NoError(err)
@@ -80,7 +80,7 @@ func Test_ingestBumpSeq(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("kahuna")
 	defer tt.Finish()
 
-	s := ingest(tt)
+	s := ingest(tt, false)
 	tt.Require.NoError(s.Err)
 
 	q := &history.Q{Session: tt.HorizonSession()}
diff --git a/services/horizon/internal/ingest/system_test.go b/services/horizon/internal/ingest/system_test.go
index e4db198a17..96765621ba 100644
--- a/services/horizon/internal/ingest/system_test.go
+++ b/services/horizon/internal/ingest/system_test.go
@@ -10,7 +10,7 @@ import (
 func TestBackfill(t *testing.T) {
 	tt := test.Start(t).ScenarioWithoutHorizon("kahuna")
 	defer tt.Finish()
-	is := sys(tt)
+	is := sys(tt, false)
 
 	err := is.ReingestSingle(10)
 	tt.Require.NoError(err)
@@ -34,7 +34,7 @@ func TestBackfill(t *testing.T) {
 func TestClearAll(t *testing.T) {
 	tt := test.Start(t).Scenario("kahuna")
 	defer tt.Finish()
-	is := sys(tt)
+	is := sys(tt, false)
 
 	err := is.ClearAll()
 
@@ -51,7 +51,7 @@ func TestValidation(t *testing.T) {
 	tt := test.Start(t).Scenario("kahuna")
 	defer tt.Finish()
 
-	sys := New(network.TestNetworkPassphrase, "", tt.CoreSession(), tt.HorizonSession())
+	sys := New(network.TestNetworkPassphrase, "", tt.CoreSession(), tt.HorizonSession(), Config{})
 
 	// intact chain
 	for i := int32(2); i <= 57; i++ {
diff --git a/services/horizon/internal/init_ingester.go b/services/horizon/internal/init_ingester.go
index 4ad16d8137..75ccf6bbb0 100644
--- a/services/horizon/internal/init_ingester.go
+++ b/services/horizon/internal/init_ingester.go
@@ -20,6 +20,9 @@ func initIngester(app *App) {
 		app.config.StellarCoreURL,
 		app.CoreSession(nil),
 		app.HorizonSession(nil),
+		ingest.Config{
+			DisableAssetStats: app.config.DisableAssetStats,
+		},
 	)
 
 	app.ingester.SkipCursorUpdate = app.config.SkipCursorUpdate
diff --git a/services/horizon/internal/init_web.go b/services/horizon/internal/init_web.go
index 6fdce8115f..0eea741859 100644
--- a/services/horizon/internal/init_web.go
+++ b/services/horizon/internal/init_web.go
@@ -143,8 +143,11 @@ func initWebActions(app *App) {
 	r.Post("/transactions", TransactionCreateAction{}.Handle)
 	r.Get("/paths", PathIndexAction{}.Handle)
 
-	// Asset related endpoints
-	r.Get("/assets", AssetsAction{}.Handle)
+	if !app.config.DisableAssetStats {
+		// Asset related endpoints
+		r.Get("/assets", AssetsAction{}.Handle)
+	}
+
 	// friendbot
 	if app.config.FriendbotURL != nil {
 		redirectFriendbot := func(w http.ResponseWriter, r *http.Request) {
diff --git a/services/horizon/main.go b/services/horizon/main.go
index fdbc6e4adc..4297ed9cde 100644
--- a/services/horizon/main.go
+++ b/services/horizon/main.go
@@ -44,6 +44,7 @@ func init() {
 	viper.BindEnv("history-retention-count", "HISTORY_RETENTION_COUNT")
 	viper.BindEnv("history-stale-threshold", "HISTORY_STALE_THRESHOLD")
 	viper.BindEnv("skip-cursor-update", "SKIP_CURSOR_UPDATE")
+	viper.BindEnv("disable-asset-stats", "DISABLE_ASSET_STATS")
 
 	rootCmd = &cobra.Command{
 		Use:   "horizon",
@@ -230,5 +231,6 @@ func initConfig() {
 		HistoryRetentionCount:  uint(viper.GetInt("history-retention-count")),
 		StaleThreshold:         uint(viper.GetInt("history-stale-threshold")),
 		SkipCursorUpdate:       viper.GetBool("skip-cursor-update"),
+		DisableAssetStats:      viper.GetBool("disable-asset-stats"),
 	}
 }