feat(oracle): default vote threshold and min voters (#1187)

* refactor(oracle): validator performance map * refactor(oracle): whitelisted pairs set * chore: update changelog * refactor(oracle): update whitelist * refactor(oracle): rename vote_target to whitelist * chore: update changelog * refactor: remove redundant getWhitelistedPairs method * refactor: move updateWhitelist to whitelist.go * refactor: merge tally.go with ballot.go * chore: update changelog * feat(oracle): change default vote threshold to 33% * feat(oracle): add min voters param * feat(oracle): add minimum number of voters * chore: update changelog
NibiruChain · Feb 8, 2023 · 63f1892 · 63f1892
1 parent 0ed0a3b
commit 63f1892
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diff --git a/.golangci.yml b/.golangci.yml
@@ -6,7 +6,7 @@ issues:
   max-same-issues: 0 # infinite
   fix: true
   exclude:
-  # see https://github.com/stretchr/testify/issues/1199#issuecomment-1215592618, testify shows vet problem
+    # see https://github.com/stretchr/testify/issues/1199#issuecomment-1215592618, testify shows vet problem
     - 'github.com\/stretchr\/testify\/suite\.Suite contains sync\.RWMutex'
 linters:
   enable:
@@ -22,4 +22,3 @@ linters-settings:
     local-prefixes: github.com/NibiruChain/nibiru
 severity:
   default-severity: error
-
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -40,6 +40,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Features
+
+* [#1187](https://github.com/NibiruChain/nibiru/pull/1187) - feat(oracle): default vote threshold and min voters
+
 ### API Breaking
 
 * [#1158](https://github.com/NibiruChain/nibiru/pull/1158) - feat(asset-registry)!: Add `AssetRegistry`

diff --git a/proto/oracle/v1beta1/oracle.proto b/proto/oracle/v1beta1/oracle.proto
@@ -67,6 +67,12 @@ message Params {
     (gogoproto.jsontag) = "twap_lookback_window,omitempty",
     (gogoproto.moretags) = "yaml:\"twap_lookback_window\""
   ];  
+
+  // The minimum number of voters (i.e. oracle validators) per pair for it to be considered a passing ballot.
+  // Recommended at least 4.
+  uint64 min_voters = 9 [
+    (gogoproto.moretags) = "yaml:\"min_voters\""
+  ];
 }
 
 // Struct for aggregate prevoting on the ExchangeRateVote.

diff --git a/x/oracle/keeper/ballot.go b/x/oracle/keeper/ballot.go
@@ -71,9 +71,21 @@ func (k Keeper) clearVotesAndPreVotes(ctx sdk.Context, votePeriod uint64) {
 }
 
 // isPassingVoteThreshold ballot is passing the threshold amount of voting power
-func isPassingVoteThreshold(ballots types.ExchangeRateBallots, thresholdVotes sdk.Int) bool {
+func isPassingVoteThreshold(ballots types.ExchangeRateBallots, thresholdVotingPower sdk.Int, minVoters uint64) bool {
 	ballotPower := sdk.NewInt(ballots.Power())
-	return !ballotPower.IsZero() && ballotPower.GTE(thresholdVotes)
+	if ballotPower.IsZero() {
+		return false
+	}
+
+	if ballotPower.LT(thresholdVotingPower) {
+		return false
+	}
+
+	if ballots.NumValidVoters() < minVoters {
+		return false
+	}
+
+	return true
 }
 
 // removeInvalidBallots removes the ballots which have not reached the vote threshold
@@ -89,7 +101,8 @@ func (k Keeper) removeInvalidBallots(
 	whitelistedPairs := set.New(k.GetWhitelistedPairs(ctx)...)
 
 	totalBondedPower := sdk.TokensToConsensusPower(k.StakingKeeper.TotalBondedTokens(ctx), k.StakingKeeper.PowerReduction(ctx))
-	voteThreshold := k.VoteThreshold(ctx).MulInt64(totalBondedPower).RoundInt()
+	thresholdVotingPower := k.VoteThreshold(ctx).MulInt64(totalBondedPower).RoundInt()
+	minVoters := k.MinVoters(ctx)
 
 	for pair, ballots := range pairBallotsMap {
 		// If pair is not whitelisted, or the ballot for it has failed, then skip
@@ -101,7 +114,7 @@ func (k Keeper) removeInvalidBallots(
 
 		// If the ballot is not passed, remove it from the whitelistedPairs set
 		// to prevent slashing validators who did valid vote.
-		if !isPassingVoteThreshold(ballots, voteThreshold) {
+		if !isPassingVoteThreshold(ballots, thresholdVotingPower, minVoters) {
 			delete(whitelistedPairs, pair)
 			delete(pairBallotsMap, pair)
 			continue

diff --git a/x/oracle/keeper/ballot_test.go b/x/oracle/keeper/ballot_test.go
@@ -5,15 +5,14 @@ import (
 	"sort"
 	"testing"
 
+	"github.com/NibiruChain/collections"
 	"github.com/cosmos/cosmos-sdk/crypto/keys/secp256k1"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/staking"
 	fuzz "github.com/google/gofuzz"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/NibiruChain/collections"
-
 	"github.com/NibiruChain/nibiru/x/common/asset"
 	"github.com/NibiruChain/nibiru/x/common/denoms"
 	"github.com/NibiruChain/nibiru/x/common/set"

diff --git a/x/oracle/keeper/keeper_test.go b/x/oracle/keeper/keeper_test.go
@@ -3,16 +3,14 @@ package keeper
 import (
 	"testing"
 
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/x/staking"
+	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 	"github.com/stretchr/testify/require"
 
 	"github.com/NibiruChain/nibiru/x/common/asset"
 	"github.com/NibiruChain/nibiru/x/common/denoms"
-
 	"github.com/NibiruChain/nibiru/x/oracle/types"
-
-	sdk "github.com/cosmos/cosmos-sdk/types"
-	"github.com/cosmos/cosmos-sdk/x/staking"
-	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
 )
 
 func TestParams(t *testing.T) {
@@ -26,6 +24,7 @@ func TestParams(t *testing.T) {
 	// Test custom params setting
 	votePeriod := uint64(10)
 	voteThreshold := sdk.NewDecWithPrec(33, 2)
+	minVoters := uint64(4)
 	oracleRewardBand := sdk.NewDecWithPrec(1, 2)
 	slashFraction := sdk.NewDecWithPrec(1, 2)
 	slashWindow := uint64(1000)
@@ -39,6 +38,7 @@ func TestParams(t *testing.T) {
 	newParams := types.Params{
 		VotePeriod:        votePeriod,
 		VoteThreshold:     voteThreshold,
+		MinVoters:         minVoters,
 		RewardBand:        oracleRewardBand,
 		Whitelist:         whitelist,
 		SlashFraction:     slashFraction,

diff --git a/x/oracle/keeper/params.go b/x/oracle/keeper/params.go
@@ -19,6 +19,12 @@ func (k Keeper) VoteThreshold(ctx sdk.Context) (res sdk.Dec) {
 	return
 }
 
+// VoteThreshold returns the minimum percentage of votes that must be received for a ballot to pass.
+func (k Keeper) MinVoters(ctx sdk.Context) (res uint64) {
+	k.paramSpace.Get(ctx, types.KeyMinVoters, &res)
+	return
+}
+
 // RewardBand returns a maxium divergence that a price vote can have from the
 // weighted median in the ballot. If a vote lies within the valid range
 // defined by:
@@ -28,7 +34,7 @@ func (k Keeper) VoteThreshold(ctx sdk.Context) (res sdk.Dec) {
 //
 // then rewards are added to the validator performance.
 // Note that if the reward band is smaller than 1 standard
-// deviation, the band is taken to be 1 standard deviation.a price
+// deviation, the band is taken to be 1 standard deviation.
 func (k Keeper) RewardBand(ctx sdk.Context) (res sdk.Dec) {
 	k.paramSpace.Get(ctx, types.KeyRewardBand, &res)
 	return

diff --git a/x/oracle/keeper/querier_test.go b/x/oracle/keeper/querier_test.go
@@ -5,11 +5,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/NibiruChain/collections"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/stretchr/testify/require"
 
-	"github.com/NibiruChain/collections"
-
 	"github.com/NibiruChain/nibiru/x/common/asset"
 	"github.com/NibiruChain/nibiru/x/common/denoms"
 	"github.com/NibiruChain/nibiru/x/oracle/types"
@@ -155,6 +154,7 @@ func TestCalcTwap(t *testing.T) {
 			newParams := types.Params{
 				VotePeriod:         types.DefaultVotePeriod,
 				VoteThreshold:      types.DefaultVoteThreshold,
+				MinVoters:          types.DefaultMinVoters,
 				RewardBand:         types.DefaultRewardBand,
 				Whitelist:          types.DefaultWhitelist,
 				SlashFraction:      types.DefaultSlashFraction,

diff --git a/x/oracle/keeper/reward_test.go b/x/oracle/keeper/reward_test.go
@@ -38,6 +38,10 @@ func setup(t *testing.T) (keeper.TestInput, types.MsgServer) {
 	require.NoError(t, err)
 	_, err = sh(input.Ctx, keeper.NewTestMsgCreateValidator(keeper.ValAddrs[2], keeper.ValPubKeys[2], stakingAmt))
 	require.NoError(t, err)
+	_, err = sh(input.Ctx, keeper.NewTestMsgCreateValidator(keeper.ValAddrs[3], keeper.ValPubKeys[3], stakingAmt))
+	require.NoError(t, err)
+	_, err = sh(input.Ctx, keeper.NewTestMsgCreateValidator(keeper.ValAddrs[4], keeper.ValPubKeys[4], stakingAmt))
+	require.NoError(t, err)
 	staking.EndBlocker(input.Ctx, input.StakingKeeper)
 
 	return input, h
@@ -50,7 +54,7 @@ func TestKeeper_RewardsDistributionMultiVotePeriods(t *testing.T) {
 	// then we simulate that after the 5 voting periods are
 	// finished no more rewards distribution happen.
 	const periods uint64 = 5
-	const validators = 3
+	const validators = 4
 	input, h := setup(t) // set vote threshold
 	params := input.OracleKeeper.GetParams(input.Ctx)
 	input.OracleKeeper.SetParams(input.Ctx, params)