multi: add keep-failed-payment-attempts flag

channeldb/db.go

@@ -251,6 +251,7 @@ type DB struct {
 	graph                     *ChannelGraph
 	clock                     clock.Clock
 	dryRun                    bool
+	keepFailedPaymentAttempts bool
 }
 
 // Open opens or creates channeldb. Any necessary schemas migrations due
@@ -305,6 +306,7 @@ func CreateWithBackend(backend kvdb.Backend, modifiers ...OptionModifier) (*DB,
 		},
 		clock:                     opts.clock,
 		dryRun:                    opts.dryRun,
+		keepFailedPaymentAttempts: opts.keepFailedPaymentAttempts,
 	}
 
 	// Set the parent pointer (only used in tests).

channeldb/options.go

@@ -61,6 +61,10 @@ type Options struct {
 	// dryRun will fail to commit a successful migration when opening the
 	// database if set to true.
 	dryRun bool
+
+	// keepFailedPaymentAttempts determines whether failed htlc attempts
+	// are kept on disk or removed to save space.
+	keepFailedPaymentAttempts bool
 }
 
 // DefaultOptions returns an Options populated with default values.
@@ -164,3 +168,11 @@ func OptionDryRunMigration(dryRun bool) OptionModifier {
 		o.dryRun = dryRun
 	}
 }
+
+// OptionKeepFailedPaymentAttempts controls whether failed payment attempts are
+// kept on disk after a payment settles.
+func OptionKeepFailedPaymentAttempts(keepFailedPaymentAttempts bool) OptionModifier {
+	return func(o *Options) {
+		o.keepFailedPaymentAttempts = keepFailedPaymentAttempts
+	}
+}

config.go

@@ -199,6 +199,10 @@ const (
 	// defaultCoinSelectionStrategy is the coin selection strategy that is
 	// used by default to fund transactions.
 	defaultCoinSelectionStrategy = "largest"
+
+	// defaultKeepFailedPaymentAttempts is the default setting for whether
+	// to keep failed payments in the database.
+	defaultKeepFailedPaymentAttempts = false
 )
 
 var (
@@ -362,6 +366,8 @@ type Config struct {
 
 	ChannelCommitBatchSize uint32 `long:"channel-commit-batch-size" description:"The maximum number of channel state updates that is accumulated before signing a new commitment."`
 
+	KeepFailedPaymentAttempts bool `long:"keep-failed-payment-attempts" description:"Keeps persistent record of all failed payment attempts for successfully settled payments."`
+
 	DefaultRemoteMaxHtlcs uint16 `long:"default-remote-max-htlcs" description:"The default max_htlc applied when opening or accepting channels. This value limits the number of concurrent HTLCs that the remote party can add to the commitment. The maximum possible value is 483."`
 
 	NumGraphSyncPeers      int           `long:"numgraphsyncpeers" description:"The number of peers that we should receive new graph updates from. This option can be tuned to save bandwidth for light clients or routing nodes."`
@@ -625,6 +631,7 @@ func DefaultConfig() Config {
 		PendingCommitInterval:     defaultPendingCommitInterval,
 		ChannelCommitBatchSize:    defaultChannelCommitBatchSize,
 		CoinSelectionStrategy:     defaultCoinSelectionStrategy,
+		KeepFailedPaymentAttempts: defaultKeepFailedPaymentAttempts,
 		RemoteSigner: &lncfg.RemoteSigner{
 			Timeout: lncfg.DefaultRemoteSignerRPCTimeout,
 		},

config_builder.go

@@ -852,6 +852,7 @@ func (d *DefaultDatabaseBuilder) BuildDatabase(
 		channeldb.OptionSetBatchCommitInterval(cfg.DB.BatchCommitInterval),
 		channeldb.OptionDryRunMigration(cfg.DryRunMigration),
 		channeldb.OptionSetUseGraphCache(!cfg.DB.NoGraphCache),
+		channeldb.OptionKeepFailedPaymentAttempts(cfg.KeepFailedPaymentAttempts),
 	}
 
 	// We want to pre-allocate the channel graph cache according to what we

routing/control_tower_test.go

@@ -48,7 +48,7 @@ var (
 func TestControlTowerSubscribeUnknown(t *testing.T) {
 	t.Parallel()
 
-	db, err := initDB()
+	db, err := initDB(false)
 	require.NoError(t, err, "unable to init db")
 
 	pControl := NewControlTower(channeldb.NewPaymentControl(db))
@@ -65,7 +65,7 @@ func TestControlTowerSubscribeUnknown(t *testing.T) {
 func TestControlTowerSubscribeSuccess(t *testing.T) {
 	t.Parallel()
 
-	db, err := initDB()
+	db, err := initDB(false)
 	require.NoError(t, err, "unable to init db")
 
 	pControl := NewControlTower(channeldb.NewPaymentControl(db))
@@ -165,16 +165,24 @@ func TestControlTowerSubscribeSuccess(t *testing.T) {
 func TestPaymentControlSubscribeFail(t *testing.T) {
 	t.Parallel()
 
-	t.Run("register attempt", func(t *testing.T) {
+	t.Run("register attempt, keep failed payments", func(t *testing.T) {
-		testPaymentControlSubscribeFail(t, true)
+		testPaymentControlSubscribeFail(t, true, true)
 	})
-	t.Run("no register attempt", func(t *testing.T) {
+	t.Run("register attempt, delete failed payments", func(t *testing.T) {
-		testPaymentControlSubscribeFail(t, false)
+		testPaymentControlSubscribeFail(t, true, false)
+	})
+	t.Run("no register attempt, keep failed payments", func(t *testing.T) {
+		testPaymentControlSubscribeFail(t, false, true)
+	})
+	t.Run("no register attempt, delete failed payments", func(t *testing.T) {
+		testPaymentControlSubscribeFail(t, false, false)
 	})
 }
 
-func testPaymentControlSubscribeFail(t *testing.T, registerAttempt bool) {
+func testPaymentControlSubscribeFail(t *testing.T, registerAttempt,
-	db, err := initDB()
+	keepFailedPaymentAttempts bool) {
+
+	db, err := initDB(keepFailedPaymentAttempts)
 	require.NoError(t, err, "unable to init db")
 
 	pControl := NewControlTower(channeldb.NewPaymentControl(db))
@@ -228,8 +236,8 @@ func testPaymentControlSubscribeFail(t *testing.T, registerAttempt bool) {
 	subscriber2, err := pControl.SubscribePayment(info.PaymentIdentifier)
 	require.NoError(t, err, "expected subscribe to succeed, but got")
 
-	// We expect all subscribers to now report the final outcome followed by
+	// We expect both subscribers to now report the final outcome followed
-	// no other events.
+	// by no other events.
 	subscribers := []*ControlTowerSubscriber{
 		subscriber1, subscriber2,
 	}
@@ -286,13 +294,17 @@ func testPaymentControlSubscribeFail(t *testing.T, registerAttempt bool) {
 	}
 }
 
-func initDB() (*channeldb.DB, error) {
+func initDB(keepFailedPaymentAttempts bool) (*channeldb.DB, error) {
 	tempPath, err := ioutil.TempDir("", "routingdb")
 	if err != nil {
 		return nil, err
 	}
 
-	db, err := channeldb.Open(tempPath)
+	db, err := channeldb.Open(
+		tempPath, channeldb.OptionKeepFailedPaymentAttempts(
+			keepFailedPaymentAttempts,
+		),
+	)
 	if err != nil {
 		return nil, err
 	}

routing/payment_lifecycle.go

@@ -55,7 +55,7 @@ func (ps paymentState) terminated() bool {
 }
 
 // needWaitForShards returns a bool to specify whether we need to wait for the
-// outcome of the shanrdHandler.
+// outcome of the shardHandler.
 func (ps paymentState) needWaitForShards() bool {
 	// If we have in flight shards and the payment is in final stage, we
 	// need to wait for the outcomes from the shards. Or if we have no more
@@ -279,7 +279,7 @@ lifecycle:
 			continue lifecycle
 		}
 
-		// If this route will consume the last remeining amount to send
+		// If this route will consume the last remaining amount to send
 		// to the receiver, this will be our last shard (for now).
 		lastShard := rt.ReceiverAmt() == currentState.remainingAmt
 

sample-lnd.conf

@@ -311,6 +311,10 @@
 ; a new commitment.
 ; channel-commit-batch-size=10
 
+; Keeps persistent record of all failed payment attempts for successfully
+; settled payments.
+; keep-failed-payment-attempts=false
+
 ; The default max_htlc applied when opening or accepting channels. This value
 ; limits the number of concurrent HTLCs that the remote party can add to the
 ; commitment. The maximum possible value is 483.