ask is removed from orderbook when balance increases

[cipig]

I posted couple asks (and bids) for COIN in different orderbook (COIN/KMD, COIN/LTC...) then sent more COIN to the address. Result: all COIN asks are gone from orderbook, bids are still there. Nothing on console/logs.

[onur-ozkan]

I have written couple of scripts to dig into this bug and found out that this bug is not directly related with mm2. The problem comes from the Electrum, blockchain.scripthash.get_balance function doesn't work consistently.

When you send y amount of coin to your wallet, and right after that if you send a rpc call to blockchain.scripthash.get_balance, you will get a result something like

    "confirmed": "x",
    "unconfirmed": y (which you sent)

This will stay as it is for a while. There is no problem with that. After a while, it will become into something like

    "confirmed": "x + y",
    "unconfirmed": 0

And there is no problem with that either. BUT(sorry for caps, need to get attention here), sometimes, electrum will response you with something like this

    "confirmed": "x + y",
    "unconfirmed": y (which must be 0 since it's confirmed and summed with confirmed balance)

This happens rarely and takes approximately 3-4 seconds to be fixed.

screenshots from my script which calls and prints the result of blockchain.scripthash.get_balance rpc function every 0.5 seconds

How does this effect us?

When balance is updated, our balance_updated function triggers, and this line returns 0 to new_volume which takes us to the this line which removes the order of the COIN.

If you track it all the way to the bottom line, it's all about this line. result.confirmed + result.unconfirmed, as I mentioned above, sometimes unconfirmed balance stucks for 2-3 seconds. In this case, this line will calculate your balance as double of your coin which you gain from another address. And when that happens, this line will calculate your sum_outputs_value more than what you actually have, and this line will calculate your sum_inputs as what you actually have. That means, this line will throw an Error and that error will become NotSufficientBalance. And if you log that error, you will see something like Not enough COIN for swap: available x+y, required at least x+(y*2).

We will find a way to overcome this problem manually in our project until they fix it. Thank you for sharing the problem with us!

[tonymorony]

Oh, thats a great research

This one KomodoPlatform/komodo-wallet#591 might be caused by it

[artemii235]

@ozkanonur Thanks for the comprehensive research! I even doubt that we should try finding a workaround on the API side - it's worth digging into Electrum code and applying the fix there instead. Let's discuss it in our call today 🙂

[artemii235]

As we are currently considering alternatives to Electrum, it doesn't worth the effort to find a workaround in the API code.