Review and Improvements to Liquidation Engine

[satojandro]

Introduction
It has come to my attention that despite Necc enabling for a maximum of 30x leverage, the 'Liquidation Price' of a trade is merely a suggestion, as the platform is quite slow in actually closing out these positions.

Problem
The ability to create trades that do not liquidate in a timely manner and at the price required create a series of cascading problems for the platform:

• Encourage traders to max out leverage, minimising downside and exponentially increasing upside;
• This is turns results in trades that should've been liquidated eventually bouncing back in the market to being profitable trades;
• Which means that not only is the treasury losing out from collecting the collateral from would be liquidated trades, but we are also constantly depleting the tresury by paying out winning trades
• The end result is having 99% utilisation rates on trades the traders can't lose on, while the treasury bleeds and we struggle to maintain the peg.

Proposal
I am not too technical and I do not understand the nature of the issue. So this is an open call to devs to look into the issue and come up with a better assessment of what could be done.

I have seen the message on the announcements of the switch to faster price feeds. This is a massive improvement which tackles a different problem. I do note that the positions that failed to liquidate were on NEAR, which has always enjoyed relatively fast price feeds. I believe the liquidation engine is a separate problem altogether.

Desired Outcomes
It goes without saying that having optimally functioning liquidation engine will greatly increase treasury revenue while minimising the exploitative behaviour that seems to have been taking place over the last few days.

Would appreciate if other people could share their experiences and views on the matter.

[ghost]

Was only liqd after my 30x NEAR long went to 180x. So, I can confirm the issue.

[ericjuta]

Deployed https://github.com/neccdao/contracts/pull/28/files, hopefully should help flakiness