chore: Remove last processed height (#167)

The `lastProcessedHeight` was introduced for fast catch up blocks for
which the fp does not have voting power. However, this case rarely
happens and is unharmful. More discussions can be found
[here](#120 (comment)).

CHANGELOG.md

@@ -47,6 +47,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 * [#148](https://github.com/babylonlabs-io/finality-provider/pull/148) Allow command `eotsd keys add` to use
 empty HD path to derive new key and use master private key.
 * [#154](https://github.com/babylonlabs-io/finality-provider/pull/154) Use sign schnorr instead of getting private key from EOTS manager
+* [#167](https://github.com/babylonlabs-io/finality-provider/pull/167) Remove last processed height
 
 ### v0.12.1
 

finality-provider/proto/finality_providers.proto

@@ -158,11 +158,8 @@ message FinalityProvider {
     string chain_id = 7;
     // last_voted_height defines the height of the last voted chain block
     uint64 last_voted_height = 8;
-    // last_processed_height defines the height of the last successfully processed block
-    // even though the vote is not cast
-    uint64 last_processed_height = 9;
     // status defines the current finality provider status
-    FinalityProviderStatus status = 10;
+    FinalityProviderStatus status = 9;
 }
 
 // FinalityProviderInfo is the basic information of a finality provider mainly for external usage
@@ -271,4 +268,4 @@ message EditFinalityProviderRequest {
 }
 
 // Define an empty response message
-message EmptyResponse {}
+message EmptyResponse {}

finality-provider/service/fp_instance.go

@@ -16,8 +16,6 @@ import (
 	"go.uber.org/atomic"
 	"go.uber.org/zap"
 
-	fppath "github.com/babylonlabs-io/finality-provider/lib/math"
-
 	"github.com/babylonlabs-io/finality-provider/clientcontroller"
 	"github.com/babylonlabs-io/finality-provider/eotsmanager"
 	fpcfg "github.com/babylonlabs-io/finality-provider/finality-provider/config"
@@ -230,8 +228,13 @@ func (fp *FinalityProviderInstance) getAllBlocksFromChan() []*types.BlockInfo {
 }
 
 func (fp *FinalityProviderInstance) shouldProcessBlock(b *types.BlockInfo) (bool, error) {
-	// check whether the block has been processed before
-	if fp.hasProcessed(b) {
+	if b.Height <= fp.GetLastVotedHeight() {
+		fp.logger.Debug(
+			"the block height is lower than last processed height",
+			zap.String("pk", fp.GetBtcPkHex()),
+			zap.Uint64("block_height", b.Height),
+			zap.Uint64("last_voted_height", fp.GetLastVotedHeight()),
+		)
 		return false, nil
 	}
 
@@ -243,7 +246,6 @@ func (fp *FinalityProviderInstance) shouldProcessBlock(b *types.BlockInfo) (bool
 	if !hasVp {
 		// the finality provider does not have voting power
 		// and it will never will at this block
-		fp.MustSetLastProcessedHeight(b.Height)
 		fp.metrics.IncrementFpTotalBlocksWithoutVotingPower(fp.GetBtcPkHex())
 		return false, nil
 	}
@@ -287,20 +289,6 @@ func (fp *FinalityProviderInstance) randomnessCommitmentLoop() {
 	}
 }
 
-func (fp *FinalityProviderInstance) hasProcessed(b *types.BlockInfo) bool {
-	if b.Height <= fp.GetLastProcessedHeight() {
-		fp.logger.Debug(
-			"the block has been processed before, skip processing",
-			zap.String("pk", fp.GetBtcPkHex()),
-			zap.Uint64("block_height", b.Height),
-			zap.Uint64("last_processed_height", fp.GetLastProcessedHeight()),
-		)
-		return true
-	}
-
-	return false
-}
-
 func (fp *FinalityProviderInstance) hasVotingPower(b *types.BlockInfo) (bool, error) {
 	power, err := fp.GetVotingPowerWithRetry(b.Height)
 	if err != nil {
@@ -500,7 +488,7 @@ func (fp *FinalityProviderInstance) CommitPubRand(tipHeight uint64) (*types.TxRe
 
 	// make sure that the start height is at least the finality activation height
 	// and updated to generate the list with the same as the committed height.
-	startHeight = fppath.MaxUint64(startHeight, activationBlkHeight)
+	startHeight = max(startHeight, activationBlkHeight)
 	// generate a list of Schnorr randomness pairs
 	// NOTE: currently, calling this will create and save a list of randomness
 	// in case of failure, randomness that has been created will be overwritten
@@ -651,11 +639,11 @@ func (fp *FinalityProviderInstance) TestSubmitFinalitySignatureAndExtractPrivKey
 }
 
 // getPollerStartingHeight gets the starting height of the poller with
-// max(lastProcessedHeight+1, lastFinalizedHeight+1, params.FinalityActivationHeight)
+// max(lastVotedHeight+1, lastFinalizedHeight+1, params.FinalityActivationHeight)
 // this ensures that:
 // (1) the fp will not vote for a height lower than params.FinalityActivationHeight
 // (2) the fp will not miss for any non-finalized blocks
-// (3) the fp will not process any blocks that have been already processed
+// (3) the fp will not process any blocks that have been already voted
 // Note: if the fp starting from the last finalized height with a gap to the last
 // processed height, the fp might miss some rewards due to not sending the votes
 // depending on the consumer chain's reward distribution mechanism
@@ -682,12 +670,11 @@ func (fp *FinalityProviderInstance) getPollerStartingHeight() (uint64, error) {
 
 	// if we have finalized blocks, consider the height after the latest finalized block
 	if len(latestFinalisedBlocks) > 0 {
-		startHeight = fppath.MaxUint64(startHeight, latestFinalisedBlocks[0].Height+1)
+		startHeight = max(startHeight, latestFinalisedBlocks[0].Height+1)
 	}
 
-	// consider the height after the last processed block
-	lastProcessedHeight := fp.GetLastProcessedHeight()
-	startHeight = fppath.MaxUint64(startHeight, lastProcessedHeight+1)
+	// consider the height after the last voted height
+	startHeight = max(startHeight, fp.GetLastVotedHeight()+1)
 
 	return startHeight, nil
 }

finality-provider/service/fp_instance_test.go

@@ -95,7 +95,6 @@ func FuzzSubmitFinalitySigs(f *testing.F) {
 
 		// check the last_voted_height
 		require.Equal(t, nextBlock.Height, fpIns.GetLastVotedHeight())
-		require.Equal(t, nextBlock.Height, fpIns.GetLastProcessedHeight())
 	})
 }
 

finality-provider/service/fp_store_adapter.go

@@ -87,17 +87,9 @@ func (fps *fpState) setStatus(s proto.FinalityProviderStatus) error {
 	return fps.s.SetFpStatus(fps.fp.BtcPk, s)
 }
 
-func (fps *fpState) setLastProcessedHeight(height uint64) error {
-	fps.mu.Lock()
-	fps.fp.LastProcessedHeight = height
-	fps.mu.Unlock()
-	return fps.s.SetFpLastProcessedHeight(fps.fp.BtcPk, height)
-}
-
-func (fps *fpState) setLastProcessedAndVotedHeight(height uint64) error {
+func (fps *fpState) setLastVotedHeight(height uint64) error {
 	fps.mu.Lock()
 	fps.fp.LastVotedHeight = height
-	fps.fp.LastProcessedHeight = height
 	fps.mu.Unlock()
 	return fps.s.SetFpLastVotedHeight(fps.fp.BtcPk, height)
 }
@@ -126,10 +118,6 @@ func (fp *FinalityProviderInstance) GetLastVotedHeight() uint64 {
 	return fp.fpState.getStoreFinalityProvider().LastVotedHeight
 }
 
-func (fp *FinalityProviderInstance) GetLastProcessedHeight() uint64 {
-	return fp.fpState.getStoreFinalityProvider().LastProcessedHeight
-}
-
 func (fp *FinalityProviderInstance) GetChainID() []byte {
 	return []byte(fp.fpState.getStoreFinalityProvider().ChainID)
 }
@@ -145,20 +133,8 @@ func (fp *FinalityProviderInstance) MustSetStatus(s proto.FinalityProviderStatus
 	}
 }
 
-func (fp *FinalityProviderInstance) SetLastProcessedHeight(height uint64) error {
-	return fp.fpState.setLastProcessedHeight(height)
-}
-
-func (fp *FinalityProviderInstance) MustSetLastProcessedHeight(height uint64) {
-	if err := fp.SetLastProcessedHeight(height); err != nil {
-		fp.logger.Fatal("failed to set last processed height",
-			zap.String("pk", fp.GetBtcPkHex()), zap.Uint64("last_processed_height", height))
-	}
-	fp.metrics.RecordFpLastProcessedHeight(fp.GetBtcPkHex(), height)
-}
-
 func (fp *FinalityProviderInstance) updateStateAfterFinalitySigSubmission(height uint64) error {
-	return fp.fpState.setLastProcessedAndVotedHeight(height)
+	return fp.fpState.setLastVotedHeight(height)
 }
 
 func (fp *FinalityProviderInstance) MustUpdateStateAfterFinalitySigSubmission(height uint64) {

finality-provider/store/fpstore.go

@@ -148,30 +148,13 @@ func (s *FinalityProviderStore) SetFpLastVotedHeight(btcPk *btcec.PublicKey, las
 		if fp.LastVotedHeight < lastVotedHeight {
 			fp.LastVotedHeight = lastVotedHeight
 		}
-		if fp.LastProcessedHeight < lastVotedHeight {
-			fp.LastProcessedHeight = lastVotedHeight
-		}
 
 		return nil
 	}
 
 	return s.setFinalityProviderState(btcPk, setFpLastVotedHeight)
 }
 
-// SetFpLastProcessedHeight sets the last processed height to the stored last processed height
-// only if it is larger than the stored one. This is to ensure the stored state to increase monotonically
-func (s *FinalityProviderStore) SetFpLastProcessedHeight(btcPk *btcec.PublicKey, lastProcessedHeight uint64) error {
-	setFpLastProcessedHeight := func(fp *proto.FinalityProvider) error {
-		if fp.LastProcessedHeight < lastProcessedHeight {
-			fp.LastProcessedHeight = lastProcessedHeight
-		}
-
-		return nil
-	}
-
-	return s.setFinalityProviderState(btcPk, setFpLastProcessedHeight)
-}
-
 func (s *FinalityProviderStore) setFinalityProviderState(
 	btcPk *btcec.PublicKey,
 	stateTransitionFn func(provider *proto.FinalityProvider) error,

finality-provider/store/storedfp.go

@@ -13,16 +13,15 @@ import (
 )
 
 type StoredFinalityProvider struct {
-	FPAddr              string
-	BtcPk               *btcec.PublicKey
-	Description         *stakingtypes.Description
-	Commission          *sdkmath.LegacyDec
-	Pop                 *proto.ProofOfPossession
-	KeyName             string
-	ChainID             string
-	LastVotedHeight     uint64
-	LastProcessedHeight uint64
-	Status              proto.FinalityProviderStatus
+	FPAddr          string
+	BtcPk           *btcec.PublicKey
+	Description     *stakingtypes.Description
+	Commission      *sdkmath.LegacyDec
+	Pop             *proto.ProofOfPossession
+	KeyName         string
+	ChainID         string
+	LastVotedHeight uint64
+	Status          proto.FinalityProviderStatus
 }
 
 func protoFpToStoredFinalityProvider(fp *proto.FinalityProvider) (*StoredFinalityProvider, error) {
@@ -49,11 +48,10 @@ func protoFpToStoredFinalityProvider(fp *proto.FinalityProvider) (*StoredFinalit
 		Pop: &proto.ProofOfPossession{
 			BtcSig: fp.Pop.BtcSig,
 		},
-		KeyName:             fp.KeyName,
-		ChainID:             fp.ChainId,
-		LastVotedHeight:     fp.LastVotedHeight,
-		LastProcessedHeight: fp.LastProcessedHeight,
-		Status:              fp.Status,
+		KeyName:         fp.KeyName,
+		ChainID:         fp.ChainId,
+		LastVotedHeight: fp.LastVotedHeight,
+		Status:          fp.Status,
 	}, nil
 }
 

itest/test_manager.go

@@ -689,7 +689,7 @@ func (tm *TestManager) InsertBTCDelegation(t *testing.T, fpPks []*btcec.PublicKe
 	delBtcPrivKey, delBtcPubKey, err := datagen.GenRandomBTCKeyPair(r)
 	require.NoError(t, err)
 
-	unbondingTime := uint16(tm.StakingParams.MinimumUnbondingTime()) + 1
+	unbondingTime := uint16(tm.StakingParams.MinUnbondingTime)
 	testStakingInfo := datagen.GenBTCStakingSlashingInfo(
 		r,
 		t,

types/stakingparams.go

@@ -31,13 +31,3 @@ type StakingParams struct {
 	// The minimum time for unbonding transaction timelock in BTC blocks
 	MinUnbondingTime uint32
 }
-
-// MinimumUnbondingTime returns the minimum unbonding time. It is the bigger value from:
-// - MinUnbondingTime
-// - CheckpointFinalizationTimeout
-func (p *StakingParams) MinimumUnbondingTime() uint32 {
-	return sdkmath.Max[uint32](
-		p.MinUnbondingTime,
-		p.FinalizationTimeoutBlocks,
-	)
-}