set min_volume to dust in orders

[cipig]

Currently mm2 sets min_volume to 0.00777 as default if nothing else is passed. Can it be set to the setting of dust from coins file instead, in case the dust setting is higher than 0.00777 (or always use the dust setting as min_volume)?
DOGE has 100000000 sats (1 DOGE): https://github.com/Komodoplatform/coins/blob/master/coins#L546
This would prevent buys of < 1 DOGE by takers from starting and failing, like in https://discord.com/channels/412898016371015680/449950331577565194/818155230298112020
Thing is also that they don't even know why it fails, they only get the 180s timeout error. Maker has this: https://dexapi.cipig.net/public/error.php?uuid=1a85e6fa-c60f-455a-9b38-5cf97ae01e00

[artemii235]

Thanks for creating the issue! It's easy to add, doing now.

[cipig]

i fear min_volume needs to be set even higher, 2 * dust, because the swap 1ee3ee1b-e034-40c9-a877-b7aba4849694 with

"maker_coin" : "DOGE",
"maker_amount" : "1",

was successful on maker side (spent takerpayment), but failed on taker side: https://dexapi.cipig.net/public/error.php?uuid=1ee3ee1b-e034-40c9-a877-b7aba4849694

dogecoin-cli decoderawtransaction 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
{
  "txid": "89ffc81bc6369e99026453ca205f41fd6f46bee2168218ce575a18e4733dbc2c",
  "hash": "89ffc81bc6369e99026453ca205f41fd6f46bee2168218ce575a18e4733dbc2c",
  "size": 301,
  "vsize": 301,
  "version": 1,
  "locktime": 1615236416,
  "vin": [
    {
      "txid": "6065817953f823c97b64886a3943c587e6775d6fa9484809f2887bb65647f740",
      "vout": 0,
      "scriptSig": {
        "asm": "3045022100dc0cfe763de91393610cf71c4aaba780a155d696b701751365cf9a3bebb3687a02207434c969e9a9aa026d776b66675360542494aca7747a94b1d2a60ae83ef4a756[ALL] 06039a188bf40b3d6f9b2c1b5148e121fc09ad42512544e4dadc7f1c730b016c 0 6304408d4660b17521028c525305d08a87a608aa257267bb5910aedbcb747e863a59da54d74815925083ac6782012088a914f737139c6e6d250dbb05a87d1bff1d6f096290c38821026879e3acedfa6a58f436c64d026e2f1f167e98898d11c6a31a8353354e7f59f1ac68",
        "hex": "483045022100dc0cfe763de91393610cf71c4aaba780a155d696b701751365cf9a3bebb3687a02207434c969e9a9aa026d776b66675360542494aca7747a94b1d2a60ae83ef4a756012006039a188bf40b3d6f9b2c1b5148e121fc09ad42512544e4dadc7f1c730b016c004c6b6304408d4660b17521028c525305d08a87a608aa257267bb5910aedbcb747e863a59da54d74815925083ac6782012088a914f737139c6e6d250dbb05a87d1bff1d6f096290c38821026879e3acedfa6a58f436c64d026e2f1f167e98898d11c6a31a8353354e7f59f1ac68"
      },
      "sequence": 4294967295
    }
  ],
  "vout": [
    {
      "value": 0.00000000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 14a912746303176912b88849297888b062049d40 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a91414a912746303176912b88849297888b062049d4088ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "D72LbRskVw2x8FNpdKvhX4UdroSkjMSHHp"
        ]
      }
    }
  ]
}

"value": 0.00000000 is not good, should be at least 1 :-)

[artemii235]

Yeah, the miner fee is deducted from the payment output upon spending attempt. I guess the min_volume = 2 x dust is too low in this case - the user will receive just 1 DOGE instead of 2, which might be quite unexpected. Maybe we should set min_volume = 100 x dust so the dust/fee is not more than 1% of trading volume?

[cipig]

Tested min_volume cases and it works as expected when i operate with base DOGE, both bid and asks (buy/sell DOGE) have base/rel min_volume to 10 DOGE (10x dust).
When i place same orders by operating with base KMD and rel DOGE, the min_volume is set in regards to KMD, because that is the base coin.
orderbook base DOGE, rel KMD:

      "base_max_volume": "74.1",
      "base_min_volume": "0.191919",
      "rel_max_volume": "3",
      "rel_min_volume": "0.00777"

base_min_volume = 0.191919 DOGE
as long as the taker operates with base DOGE when he tries to buy/sell DOGE it will work fine, which i guess is the common case

[cipig]

last case covered in above PR, all orders in DOGE/KMD have "base_min_volume": "10" DOGE, bids and asks, and "rel_min_volume": "0.14xxx KMD, which is the same as 10 DOGE