routing: fix and enhance logging

channeldb/payment_control.go

@@ -424,7 +424,9 @@ func (p *PaymentControl) RegisterAttempt(paymentHash lntypes.Hash,
 		// Ensure we aren't sending more than the total payment amount.
 		sentAmt, _ := payment.SentAmt()
 		if sentAmt+amt > payment.Info.Value {
-			return ErrValueExceedsAmt
+			return fmt.Errorf("%w: attempted=%v, payment amount="+
+				"%v", ErrValueExceedsAmt, sentAmt+amt,
+				payment.Info.Value)
 		}
 
 		htlcsBucket, err := bucket.CreateBucketIfNotExists(

channeldb/payment_control_test.go

@@ -734,10 +734,7 @@ func TestPaymentControlMultiShard(t *testing.T) {
 		b := *attempt
 		b.AttemptID = 3
 		_, err = pControl.RegisterAttempt(info.PaymentIdentifier, &b)
-		if err != ErrValueExceedsAmt {
-			t.Fatalf("expected ErrValueExceedsAmt, got: %v",
-				err)
-		}
+		require.ErrorIs(t, err, ErrValueExceedsAmt)
 
 		// Fail the second attempt.
 		a := attempts[1]

routing/payment_lifecycle.go

@@ -179,7 +179,7 @@ func (p *paymentLifecycle) resumePayment(ctx context.Context) ([32]byte,
 	for _, a := range payment.InFlightHTLCs() {
 		a := a
 
-		log.Infof("Resuming payment shard %v for payment %v",
+		log.Infof("Resuming HTLC attempt %v for payment %v",
 			a.AttemptID, p.identifier)
 
 		p.resultCollector(&a)
@@ -463,6 +463,8 @@ func (p *paymentLifecycle) collectResultAsync(attempt *channeldb.HTLCAttempt) {
 func (p *paymentLifecycle) collectResult(attempt *channeldb.HTLCAttempt) (
 	*attemptResult, error) {
 
+	log.Tracef("Collecting result for attempt %v", spew.Sdump(attempt))
+
 	// We'll retrieve the hash specific to this shard from the
 	// shardTracker, since it will be needed to regenerate the circuit
 	// below.
@@ -663,8 +665,8 @@ func (p *paymentLifecycle) createNewPaymentAttempt(rt *route.Route,
 func (p *paymentLifecycle) sendAttempt(
 	attempt *channeldb.HTLCAttempt) (*attemptResult, error) {
 
-	log.Debugf("Attempting to send payment %v (pid=%v)", p.identifier,
-		attempt.AttemptID)
+	log.Debugf("Sending HTLC attempt(id=%v, amt=%v) for payment %v",
+		attempt.AttemptID, attempt.Route.TotalAmount, p.identifier)
 
 	rt := attempt.Route
 

routing/router.go

@@ -1133,6 +1133,9 @@ func (r *ChannelRouter) SendToRouteSkipTempErr(htlcHash lntypes.Hash,
 func (r *ChannelRouter) sendToRoute(htlcHash lntypes.Hash, rt *route.Route,
 	skipTempErr bool) (*channeldb.HTLCAttempt, error) {
 
+	log.Debugf("SendToRoute for payment %v with skipTempErr=%v",
+		htlcHash, skipTempErr)
+
 	// Calculate amount paid to receiver.
 	amt := rt.ReceiverAmt()