From de42eccd2778ea5b6d5dea2a57ff6bed0617281d Mon Sep 17 00:00:00 2001 From: abitmore Date: Wed, 22 Aug 2018 09:16:37 -0400 Subject: [PATCH] Added description about limits --- bsip-0042.md | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/bsip-0042.md b/bsip-0042.md index 9cde31c..a33c5db 100644 --- a/bsip-0042.md +++ b/bsip-0042.md @@ -57,6 +57,14 @@ correct direction, the price should move towards par. If the price moved too little, we adjust more; if the price moved too much, we adjust less. Finally this will lead to a stable result. +We may consider setting a hard limit on the offset which may make us feel safer. +Actually, to be safe, we do need to start with a small offset, and adjust little +by little. Since it's expected that the best offset will be figured out by the +negative feedback mechanism, a preset limit may impact the mechanism negatively. +A few witnesses publishing too far away offset doesn't harm much because +they won't move the median much. In addition, stake holders may vote down +perceived bad actors. + ### Risks All the adjustments (price feed, or MCR, or MSSR) in a downtrend actually looses @@ -129,13 +137,22 @@ When witness publishing a price feed, after got price of BTS from exchanges (assuming it's `P`), check trading price of the publishing SmartCoin, adjust `P` with an algorithm. +To be safe, the algorithm should start with a small offset, or a value near +the median, and adjust the offset little by little. + The algorithm should implement negative feedback, that said, it should track historical adjustments and historical differences on trading prices of SmartCoins, and make new adjustments accordingly. -We don't force all witnesses to use same algorithm, instead, witnesses are +We don't force all witnesses to use a same algorithm, instead, witnesses are encouraged to implement different algorithms for same goal. +We also don't set a hard limit about how much the offset should be within, in +order to let the negative feed back mechasim find the best result by itself. +Witnesses should make their own decisions on whether to set a hard limit and +how much should it be if need to set one, generally, to reduce impacts caused +by bugs. + # Discussion [To be added]