Error while distributing rewards

[DylanVerstraete]

Seen on testnet

2023-02-28 10:44:36 💤 Idle (8 peers), best: #7153780 (0xfb24…88ff), finalized #7153777 (0x5f93…433b), ⬇ 9.3kiB/s ⬆ 13.0kiB/s    
2023-02-28 10:44:41 💤 Idle (8 peers), best: #7153780 (0xfb24…88ff), finalized #7153778 (0x8674…852b), ⬇ 11.4kiB/s ⬆ 12.6kiB/s    
2023-02-28 10:44:42 Transfering: 25 from contract twin  to foundation account     
2023-02-28 10:44:42 error while distributing cultivation rewards <wasm:stripped>

[renauter]

Investigation of the case on Testnet

Looking at block #7153778 we can see the failing extrinsic:
https://polkadot.js.org/apps/?rpc=wss%3A%2F%2F/tfchain.test.grid.tf#/explorer/query/7153778

It corresponds to a failing transaction from this account: 5G3t9VaCQf5M2PawGz3iENYMwzpbMkaqZ1nxavnEaH2oPa3K
which state at this block is:

The error Balances.KeepAlive / Transfer/payment would kill account is triggered because of

  consumers: 1
  providers: 1

which returns false here:

https://github.com/paritytech/substrate/blob/cb4f2491b00af7d7817f3a54209c26b20faa1f51/frame/system/src/lib.rs#L1233

	/// True if the account has no outstanding consumer references or more than one provider.
	pub fn can_dec_provider(who: &T::AccountId) -> bool {
		let a = Account::<T>::get(who);
		a.consumers == 0 || a.providers > 1
	}

while transferring in the transfer() function:

https://github.com/paritytech/substrate/blob/cb4f2491b00af7d7817f3a54209c26b20faa1f51/frame/balances/src/lib.rs#L1546

[renauter]

Some documentation about Account data structures
https://docs.substrate.io/reference/account-data-structures/
https://substrate.stackexchange.com/questions/263/what-is-the-meaning-of-the-account-provider-sufficients-and-consumer

[renauter]

But no idea about the account 5G3t9VaCQf5M2PawGz3iENYMwzpbMkaqZ1nxavnEaH2oPa3K, in which context it is billed and how it get in the consumers: 1 / providers: 1 case

Just found it was a billing for contract ID 716 which is a node contract

[DylanVerstraete]

I think this error is because we try to distribute rewards from contracts that are in grace but the balance of the user's twin is not enough to cover the costs. We should actually not try to distribute rewards when a contract is in grace period.

[renauter]

I think this error is because we try to distribute rewards from contracts that are in grace but the balance of the user's twin is not enough to cover the costs. We should actually not try to distribute rewards when a contract is in grace period.

We distribute rewards inside handle_lock()
And just before we prevent to do it if contract is in grace period
See here:

tfchain/substrate-node/pallets/pallet-smart-contract/src/lib.rs

Line 1162 in fc5e182

if matches!(contract.state, types::ContractState::GracePeriod(_)) {

So I am not sure it is the right cause...

[DylanVerstraete]

Hmm okay, might need to dig deeper then

[xmonader]

should this be moved to blocked?

[DylanVerstraete]

After some investigation I think this issue will be resolved by: #631

[A-Harby]

Closing as issue was fixed in #631 and haven't reproduce again on the chain.