BitShares Forum

Main => General Discussion => Topic started by: alt on April 23, 2019, 03:16:18 pm

Title: lucky us, avoid from a disaster
Post by: alt on April 23, 2019, 03:16:18 pm

becasue of this upgrade, we will get a wrong margin call price for each debt from the old api.
based on the BSIP, witness should protect black swan for CNY and USD, so they should give a feed price 10USD/BTS and 10CNY/BTS
this will destroy exist bitCNY and bitUSD, make it only worth around 0.1 FIAT CNY.
the godd thing is seems only gdex-witness run the black swan protect logic, we have avoid from this disaster.

Title: Re: lucky us, avoid from a disaster
Post by: alt on April 23, 2019, 03:19:52 pm

but please make sure every witness have run the black swan protect logic with correct api ASAP.
and make sure announce for any tiny change of the base protocol please!

Title: Re: lucky us, avoid from a disaster
Post by: btspp on April 23, 2019, 03:47:02 pm

The root cause of this event should be here: https://github.com/bitshares/bitshares-ui/issues/2634

It has been confirmed that the following methods currently used by btspp dynamically calculate the price of black swan protection.

Quote

Call_price = (collateral × MCR) ÷ debt

The obsolete call_price field is not used.

Title: Re: lucky us, avoid from a disaster
Post by: Bangzi on April 23, 2019, 04:17:08 pm

There is skip change protection:

# skip publishing a feed if price goes above this percentage
skip_change: 30

Title: Re: lucky us, avoid from a disaster
Post by: zapata42 on April 23, 2019, 08:23:40 pm

Note that Zapata/bitshares-pricefeed (https://github.com/Zapata/bitshares-pricefeed) don't had the issue, even with global settlement activated (see the code (https://github.com/Zapata/bitshares-pricefeed/blob/develop/bitshares_pricefeed/pricefeed.py#L123)).

The core team announced the change weeks before the network update, and in my case the pricefeed code was checked.

You can also visualize what happened today on the pricefeed tracker (http://pricefeed-tracker.dex.trading/).

(https://i.imgur.com/2srhm6U.png)