[Question]LTC example gives a "dust" error.

[BlackTurtle123]

I was trying to run the LTC example.
When the framework picks up the LTC, it tried to process everything resulting in next encoded tx, I have added some more debug statements in the send_coin:
[2018-04-22 10:55:40,467] INFO {waves-gw.TransactionAttemptListService} - Trying to complete attempt_list '0fc975cb-31c3-45b5-8836-a77ede465639' 0.10969429 optimized_unspents[{'txid': 'de13dab6433727d95359b56cc315ae2e69e1444ebaf0a41e75c9f961186cb14f', 'vout': 0, 'address': 'LcuwKVW2iW5465wC3xL6DZkEoXn8rgqiSK', 'account': '', 'scriptPubKey': '76a914c209fd3e630060762f9c264bd6314231b014674a88ac', 'amount': Decimal('0.11969429'), 'confirmations': 308, 'spendable': True, 'solvable': True, 'safe': True}] receiver= 0.09969429 receiver= 0.01000000 unspents 0.11969429 02000000014fb16c1861f9c9751ea4f0ba4e44e1692eae15c36cb55953d9273743b6da13de0000000000ffffffff03151f9800000000001976a9146bdf32077c94f3b6bdea22e9ccb1901386a25fb988ac40420f00000000001976a914cc18f111adafcf2e9f7c6f62e76f157b71d32d8a88ac00000000000000001976a914c209fd3e630060762f9c264bd6314231b014674a88ac00000000 {'hex': '02000000014fb16c1861f9c9751ea4f0ba4e44e1692eae15c36cb55953d9273743b6da13de000000006a4730440220023215ca5cf2ed2234f8ad00a9006e8e47d76f4c20e392317aac80018738bab302206002e5d72f5237586fe082d649b349435a0d8538a9b8134224190e1b6c1b00cd012102dd13a7cfa4f408113715c1bbb997ee60a11f1fbb72ba51edfe4acb70b5444573ffffffff03151f9800000000001976a9146bdf32077c94f3b6bdea22e9ccb1901386a25fb988ac40420f00000000001976a914cc18f111adafcf2e9f7c6f62e76f157b71d32d8a88ac00000000000000001976a914c209fd3e630060762f9c264bd6314231b014674a88ac00000000', 'complete': True}

The framework tryes to broadcast it for a while and then return a 64 dust error.
Am I missing something in my daemon config?
Since I didn't edited the LTC code.
Or is it something inside my config.cfg file that is messed up?

[henning96]

Your amount (0.11969429) should be high enough, so that the network should not reject it as a Dust transaction (SPAM). I don't know what is happening here. Maybe, you could try to increase the Fee.

[henning96]

I've just done a short test and the LTC Gateway still works. I was able to send in both directions.

[BlackTurtle123]

With what amounts @henning96 ?
Also could this be caused by a faulty ltc daemon?

[BlackTurtle123]

Even a 0.05 fee tells me it's dust I am sending..
0.06969429 optimized_unspents[{'txid': 'de13dab6433727d95359b56cc315ae2e69e1444ebaf0a41e75c9f961186cb14f', 'vout': 0, 'address': 'LcuwKVW2iW5465wC3xL6DZkEoXn8rgqiSK', 'account': '', 'scriptPubKey': '76a914c209fd3e630060762f9c264bd6314231b014674a88ac', 'amount': Decimal('0.11969429'), 'confirmations': 519, 'spendable': True, 'solvable': True, 'safe': True}] receiver= 0.05969429 receiver= 0.01000000 unspents 0.11969429 02000000014fb16c1861f9c9751ea4f0ba4e44e1692eae15c36cb55953d9273743b6da13de0000000000ffffffff0315165b00000000001976a9146bdf32077c94f3b6bdea22e9ccb1901386a25fb988ac40420f00000000001976a914cc18f111adafcf2e9f7c6f62e76f157b71d32d8a88ac00000000000000001976a914c209fd3e630060762f9c264bd6314231b014674a88ac00000000 {'hex': '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', 'complete': True}

[henning96]

I am using a fee of 0.02 LTC. I send 0.1 wLTC to the Gateway.
It is possible that this is a problem with your LTC daemon. I have version 0.15.1 of Litcoin Core installed.

[BlackTurtle123]

{ "lock_time":0, "size":153, "inputs":[ { "prev_out":{ "index":0, "hash":"de13dab6433727d95359b56cc315ae2e69e1444ebaf0a41e75c9f961186cb14f" }, "script":"" } ], "version":2, "vin_sz":1, "hash":"4e036dc7396b38ab3aade42a31a9c9c2eb4280784f8ddec2e9a3f015decf7c7b", "vout_sz":3, "out":[ { "script_string":"OP_DUP OP_HASH160 6bdf32077c94f3b6bdea22e9ccb1901386a25fb9 OP_EQUALVERIFY OP_CHECKSIG", "address":"1AqNgR8LwjxBMoPFmqQRXuR1Bkuk2YRHbL", "value":5969429, "script":"76a9146bdf32077c94f3b6bdea22e9ccb1901386a25fb988ac" }, { "script_string":"OP_DUP OP_HASH160 cc18f111adafcf2e9f7c6f62e76f157b71d32d8a OP_EQUALVERIFY OP_CHECKSIG", "address":"1KcAj7TsNtHxzDJc7UXaT8kA3NbSUgFyFQ", "value":1000000, "script":"76a914cc18f111adafcf2e9f7c6f62e76f157b71d32d8a88ac" }, { "script_string":"OP_DUP OP_HASH160 c209fd3e630060762f9c264bd6314231b014674a OP_EQUALVERIFY OP_CHECKSIG", "address":"1Jgz4HCCdqpzqHF2spLnwYgUbKQrmZPE2n", "value":0, "script":"76a914c209fd3e630060762f9c264bd6314231b014674a88ac" } ] }

While decoding it and relooking, it says value:0 for the bottom one, does this maybee cause the error?

[BlackTurtle123]

WavesGatewayLTCExample/waves_litecoin_gateway/lib/litecoin_transaction_service.py

Line 85 in 14aaf9d

outputs[attempt.sender] = unspents_amount - attempt.fee - overall_amount

This line is adding a recipient that has 0 balans.
My work around to let it work is next:

if 0 < unspents_amount - attempt.fee - overall_amount: 
    outputs[attempt.sender] = unspents_amount - attempt.fee - overall_amount 

From that moment ltc succeeded in creating valid transactions

[henning96]

Does this mean that your Gateway LTC address does not have any LTC, although it should have?
The line you are trying to add should not be necessary.
Your Gateway seems to be in an invalid state.

[BlackTurtle123]

When transfering inside this happens. So from Ltc to TN.
I do have ltc on it, but this happens when the temporary addr that is linked with the tn adress is sending it away. And on those temporary addr shouldnt be any ltc be left over if I got it right?
Anyway, there was ltc on the correct addr, to pay for everything, when I added this line, the gateway did what it needed to do , as far for the ltc part.
I started everything from clean addr when I setted up the gateway.
In this error the attempt.sender also isnt the gateway ltc addr but the temporary gateway ltc addr, linked to the TN (or normal waves) accounts.
Other way around I couldnt test because the strange bug I can't seem to resolve....

[BlackTurtle123]

Hello @henning96
I got another dust error this is the case:

1. I reduced fees from 0.02 to 0.003.
2. A tx has been done and the optimilized calculates perfect, except the return will be below dust treshold (100000)
3. The litecoin RPC complains about the dust treshold.

Possible solutions:
-Increase fees to 0.02 for paying the dust penalty, and this don't require code change (not really liked amongst end users ofc)
-Change to code to check for:
=> if return = 0 exclude it
=>if return is above 100000 => accept return
=>all other cases => add the return to the gateway fees or to the tx fees.

Since paying paying almost 7 time to much in fees seems a bit to much I have implemented and tested the second version.
You are potentially wasting everytime a bit of money, but by bringing the fees down, and sending the dust to the gateway owner, nothing goes lost. And you can actually for a total off 0.013 have tx processed and paid the gateway 0.01.

It would be good if you could give your view and opinion about this.

[henning96]

In my opinion, it should be possible to calculate the fee dynamically based on the amount. This would not require big changes in the framework. Then, you can implement your custom logic for the LTC Gateway in the FeeService.

[BlackTurtle123]

Why would we want to calculate fee's dynamically?
It's always more interesting to "throw" dust away then to pay more fees.

[henning96]

Because we can't just throw transactions away. How would you explain that to the user of the Gateway?

[BlackTurtle123]

Increasing fees is the same as throwing "dust away" since when u increase fees to 0.02 instead 0.003 the gateway and users lost 0.017
by "throwing" dust away, the users/gateway loses max 0.001.

I don't think dynamic fees would be handy, I think however adding a minimal treshold for sending to the gateway => aka fees+0.001 would be better.
Since this prevent being dust is send, if it's below they lost it.

But we would need to explain this more clearly in the guy I believe if we go this route.

I get your logic, but by increasing fees, you lose more...

[BlackTurtle123]

Also the enduser will never know what fees he has to pay