feat(prover): use --guardian.submissionDelay flag (#730)

cmd/flags/prover.go

@@ -96,18 +96,6 @@ var (
 		Usage:    "Minimum accepted fee for generating a SGX + zkVM proof",
 		Category: proverCategory,
 	}
-	// Guardian prover related.
-	GuardianProver = &cli.StringFlag{
-		Name:     "guardianProver",
-		Usage:    "GuardianProver contract `address`",
-		Category: proverCategory,
-	}
-	GuardianProofSubmissionDelay = &cli.DurationFlag{
-		Name:     "guardian.submissionDelay",
-		Usage:    "Guardian proof submission delay",
-		Value:    0 * time.Second,
-		Category: proverCategory,
-	}
 	// Running mode
 	ContesterMode = &cli.BoolFlag{
 		Name:     "mode.contester",
@@ -160,6 +148,17 @@ var (
 		Category: proverCategory,
 	}
 	// Guardian prover specific flag
+	GuardianProver = &cli.StringFlag{
+		Name:     "guardianProver",
+		Usage:    "GuardianProver contract `address`",
+		Category: proverCategory,
+	}
+	GuardianProofSubmissionDelay = &cli.DurationFlag{
+		Name:     "guardian.submissionDelay",
+		Usage:    "Guardian proof submission delay",
+		Value:    1 * time.Hour,
+		Category: proverCategory,
+	}
 	EnableLivenessBondProof = &cli.BoolFlag{
 		Name:     "prover.enableLivenessBondProof",
 		Usage:    "Toggles whether the proof is a dummy proof or returns keccak256(RETURN_LIVENESS_BOND) as proof",

prover/event_handler/block_proposed.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"context"
+	"crypto/rand"
 	"errors"
 	"fmt"
 	"math/big"
@@ -22,8 +23,9 @@ import (
 )
 
 var (
-	errL1Reorged         = errors.New("L1 reorged")
-	proofExpirationDelay = 1 * time.Minute
+	errL1Reorged                           = errors.New("L1 reorged")
+	proofExpirationDelay                   = 1 * time.Minute
+	submissionDelayRandomBumpRange float64 = 20
 )
 
 // BlockProposedEventHandler is responsible for handling the BlockProposed event as a prover.
@@ -41,6 +43,7 @@ type BlockProposedEventHandler struct {
 	contesterMode         bool
 	proveUnassignedBlocks bool
 	tierToOverride        uint16
+	submissionDelay       time.Duration
 }
 
 // NewBlockProposedEventHandlerOps is the options for creating a new BlockProposedEventHandler.
@@ -57,6 +60,7 @@ type NewBlockProposedEventHandlerOps struct {
 	BackOffMaxRetrys      uint64
 	ContesterMode         bool
 	ProveUnassignedBlocks bool
+	SubmissionDelay       time.Duration
 }
 
 // NewBlockProposedEventHandler creates a new BlockProposedEventHandler instance.
@@ -75,6 +79,7 @@ func NewBlockProposedEventHandler(opts *NewBlockProposedEventHandlerOps) *BlockP
 		opts.ContesterMode,
 		opts.ProveUnassignedBlocks,
 		0,
+		opts.SubmissionDelay,
 	}
 }
 
@@ -216,6 +221,23 @@ func (h *BlockProposedEventHandler) checkL1Reorg(
 	return nil
 }
 
+// getRandomBumpedSubmissionDelay returns a random bumped submission delay.
+func (h *BlockProposedEventHandler) getRandomBumpedSubmissionDelay() (time.Duration, error) {
+	if h.submissionDelay == 0 {
+		return h.submissionDelay, nil
+	}
+
+	randomBump, err := rand.Int(
+		rand.Reader,
+		new(big.Int).SetUint64(uint64(h.submissionDelay.Seconds()*submissionDelayRandomBumpRange/100)),
+	)
+	if err != nil {
+		return 0, err
+	}
+
+	return time.Duration(h.submissionDelay.Seconds()+float64(randomBump.Uint64())) * time.Second, nil
+}
+
 // checkExpirationAndSubmitProof checks whether the proposed block's proving window is expired,
 // and submits a new proof if necessary.
 func (h *BlockProposedEventHandler) checkExpirationAndSubmitProof(
@@ -311,6 +333,13 @@ func (h *BlockProposedEventHandler) checkExpirationAndSubmitProof(
 	// The current prover is the assigned prover, or the proving window is expired,
 	// try to submit a proof for this proposed block.
 	tier := e.Meta.MinTier
+
+	// Get a random bumped submission delay, if necessary.
+	submissionDelay, err := h.getRandomBumpedSubmissionDelay()
+	if err != nil {
+		return err
+	}
+
 	if h.tierToOverride != 0 {
 		tier = h.tierToOverride
 	}
@@ -320,12 +349,15 @@ func (h *BlockProposedEventHandler) checkExpirationAndSubmitProof(
 		"blockID", e.BlockId,
 		"assignProver", e.AssignedProver,
 		"minTier", e.Meta.MinTier,
+		"submissionDelay", submissionDelay,
 		"tier", tier,
 	)
 
 	metrics.ProverProofsAssigned.Add(1)
 
-	h.proofSubmissionCh <- &proofProducer.ProofRequestBody{Tier: tier, Event: e}
+	time.AfterFunc(submissionDelay, func() {
+		h.proofSubmissionCh <- &proofProducer.ProofRequestBody{Tier: tier, Event: e}
+	})
 
 	return nil
 }

prover/event_handler/block_proposed_test.go

@@ -26,10 +26,41 @@ func (s *EventHandlerTestSuite) TestBlockProposedHandle() {
 		ContesterMode:         true,
 		ProveUnassignedBlocks: true,
 	}
-	handler := NewBlockProposedEventHandler(
-		opts,
-	)
+	handler := NewBlockProposedEventHandler(opts)
 	e := s.ProposeAndInsertValidBlock(s.proposer, s.calldataSyncer)
 	err := handler.Handle(context.Background(), e, func() {})
 	s.Nil(err)
 }
+
+func (s *EventHandlerTestSuite) TestGetRandomBumpedSubmissionDelay() {
+	opts := &NewBlockProposedEventHandlerOps{
+		SharedState:           &state.SharedState{},
+		ProverAddress:         common.Address{},
+		GenesisHeightL1:       0,
+		RPC:                   s.RPCClient,
+		ProofGenerationCh:     make(chan *proofProducer.ProofWithHeader),
+		AssignmentExpiredCh:   make(chan *bindings.TaikoL1ClientBlockProposed),
+		ProofSubmissionCh:     make(chan *proofProducer.ProofRequestBody),
+		ProofContestCh:        make(chan *proofProducer.ContestRequestBody),
+		BackOffRetryInterval:  1 * time.Minute,
+		BackOffMaxRetrys:      5,
+		ContesterMode:         true,
+		ProveUnassignedBlocks: true,
+	}
+	handler1 := NewBlockProposedEventHandler(opts)
+
+	delay, err := handler1.getRandomBumpedSubmissionDelay()
+	s.Nil(err)
+	s.Zero(delay)
+
+	opts.SubmissionDelay = 1 * time.Hour
+	handler2 := NewBlockProposedEventHandler(opts)
+	delay, err = handler2.getRandomBumpedSubmissionDelay()
+	s.Nil(err)
+	s.NotZero(delay)
+	s.Greater(delay.Seconds(), opts.SubmissionDelay.Seconds())
+	s.Less(
+		delay.Seconds(),
+		opts.SubmissionDelay.Seconds()*(1+(submissionDelayRandomBumpRange/100)),
+	)
+}

prover/init.go

@@ -209,6 +209,7 @@ func (p *Prover) initEventHandlers() {
 		ProveUnassignedBlocks: p.cfg.ProveUnassignedBlocks,
 	}
 	if p.IsGuardianProver() {
+		opts.SubmissionDelay = p.cfg.GuardianProofSubmissionDelay
 		p.blockProposedHandler = handler.NewBlockProposedEventGuardianHandler(
 			&handler.NewBlockProposedGuardianEventHandlerOps{
 				NewBlockProposedEventHandlerOps: opts,