feat(x/perp): the 'q position' query should expose 'marginRatioMark', 'marginRatioIndex', (and 'blockHeight')

[onikonychev]

Context

Liquidator is using this margin_ratio value to detect underwater positions. Liquidation condition based on mark price happens much sooner than TWAP and liquidator makes a long series of useless attempts until TWAP price reaches the mark price value.

Request is to return margin_ratio based on TWAP price.

Solution

Return both margin ratios so that the the liquidator has awareness of "underwater" status even if the mark and index prices diverge substantially.

[NibiruHeisenberg]

I'll return the MaxPnL (between spot and twap) since that's what the liquidation codepath checks for when liquidating.

[onikonychev]

I think I found a bug here. The updated logic works well for newly created positions. Margin ratio is tracked well and liquidation occurs properly.

But if the same trader after being liquidated opens a new position, his margin ratio is tracked wrongly. Position state is returning margin_ratio=0.059 but attempt to liquidate fails.

nibid q perp trader-position nibi14jvt2vldx8p5nnnmlxshcppqz7s5ys4mkchcym ubtc:unusd
{
   "position":{
      "trader_address":"nibi14jvt2vldx8p5nnnmlxshcppqz7s5ys4mkchcym",
      "pair":{
         "token0":"ubtc",
         "token1":"unusd"
      },
      "size":"1638.742599569168112704",
      "margin":"429686.503503750692187819",
      "open_notional":"4296865.035037506921878188",
      "last_update_cumulative_premium_fraction":"-442.146000081041666666",
      "block_number":"512"
   },
   "position_notional":"4111277.435630248352366047",
   "unrealized_pnl":"-185587.599407258569512141",
   "margin_ratio":"0.059373007032076487"
}


# Here liquidator tries to liquidate this

ERROR:root:Failed tx execution: failed to simulate tx : <_InactiveRpcError of RPC that terminated with:
	status = StatusCode.UNKNOWN
	details = "failed to execute message; message index: 0: margin is higher than required maintenance margin ratio"
	debug_error_string = "{"created":"@1659712567.493972000","description":"Error received from peer ipv6:[::1]:9090","file":"src/core/lib/surface/call.cc","file_line":967,"grpc_message":"failed to execute message; message index: 0: margin is higher than required maintenance margin ratio","grpc_status":2}"
>

^^ @NibiruHeisenberg

[NibiruHeisenberg]

Interesting, I'll take a look.

[onikonychev]

Latest update:
Recent fix returns margin_ratio based on MaxPnL which is correct if Oracle price is close to Mark Price. In case of >10% divergence margin_ratio returned is not actual because internally chain liquidation uses oracle price instead. And this leads to useless liquidation attempts and ugly logging / metrics.