Merge pull request #930 from iotaledger/fix/chaineviction

Fix: Bug with chain eviction

pkg/protocol/chain.go

@@ -223,8 +223,6 @@ func (c *Chain) initLogger() (shutdown func()) {
 // initDerivedProperties initializes the behavior of this chain by setting up the relations between its properties.
 func (c *Chain) initDerivedProperties() (shutdown func()) {
 	return lo.BatchReverse(
-		c.deriveWarpSyncMode(),
-
 		c.shouldEvict.OnTrigger(func() { go c.IsEvicted.Trigger() }),
 
 		lo.BatchReverse(
@@ -245,7 +243,13 @@ func (c *Chain) initDerivedProperties() (shutdown func()) {
 			}),
 		),
 
-		c.Engine.WithNonEmptyValue(c.deriveOutOfSyncThreshold),
+		c.Engine.WithNonEmptyValue(func(engine *engine.Engine) (teardown func()) {
+			return lo.BatchReverse(
+				c.deriveWarpSyncMode(engine),
+
+				c.deriveOutOfSyncThreshold(engine),
+			)
+		}),
 	)
 }
 
@@ -268,16 +272,16 @@ func (c *Chain) deriveShouldEvict(forkingPoint *Commitment, parentChain *Chain)
 }
 
 // deriveWarpSyncMode defines how a chain determines whether it is in warp sync mode or not.
-func (c *Chain) deriveWarpSyncMode() func() {
-	return c.WarpSyncMode.DeriveValueFrom(reactive.NewDerivedVariable3(func(warpSyncMode bool, latestSyncedSlot iotago.SlotIndex, latestSeenSlot iotago.SlotIndex, outOfSyncThreshold iotago.SlotIndex) bool {
+func (c *Chain) deriveWarpSyncMode(engine *engine.Engine) func() {
+	return c.WarpSyncMode.DeriveValueFrom(reactive.NewDerivedVariable4(func(warpSyncMode bool, engineInitialized bool, latestSyncedSlot iotago.SlotIndex, latestSeenSlot iotago.SlotIndex, outOfSyncThreshold iotago.SlotIndex) bool {
 		// if warp sync mode is enabled, keep it enabled until we have synced all slots
 		if warpSyncMode {
-			return latestSyncedSlot < latestSeenSlot
+			return engineInitialized && latestSyncedSlot < latestSeenSlot
 		}
 
 		// if warp sync mode is disabled, enable it only if we fall below the out of sync threshold
-		return latestSyncedSlot < outOfSyncThreshold
-	}, c.LatestSyncedSlot, c.chains.LatestSeenSlot, c.OutOfSyncThreshold, c.WarpSyncMode.Get()))
+		return engineInitialized && latestSyncedSlot < outOfSyncThreshold
+	}, engine.InitializedEvent(), c.LatestSyncedSlot, c.chains.LatestSeenSlot, c.OutOfSyncThreshold, c.WarpSyncMode.Get()))
 }
 
 // deriveChildChains defines how a chain determines its ChildChains (by adding each child to the set).

pkg/protocol/commitment.go

@@ -324,15 +324,6 @@ func (c *Commitment) deriveChain(parent *Commitment) func() {
 			return currentChain
 		}
 
-		// If we are the main child of our parent, and our chain is not the parent chain,
-		// then we inherit the parent chain and evict the current one.
-		// We will spawn a new one if we ever change back to not being the main child.
-		// Here we basically move commitments to the parent chain.
-		if currentChain != nil && currentChain != parentChain {
-			// TODO: refactor it to use a dedicated WorkerPool
-			go currentChain.IsEvicted.Trigger()
-		}
-
 		return parentChain
 	}, c.IsRoot, parent.MainChild, parent.Chain, c.Chain.Get()))
 }
@@ -368,8 +359,8 @@ func (c *Commitment) deriveIsAboveLatestVerifiedCommitment(parent *Commitment) f
 // deriveRequestAttestations derives the RequestAttestations flag of this Commitment which is true if our Chain is
 // requesting attestations (while not having an engine), and we are the directly above the latest attested Commitment.
 func (c *Commitment) deriveRequestAttestations(chain *Chain, parent *Commitment) func() {
-	return c.RequestAttestations.DeriveValueFrom(reactive.NewDerivedVariable4(func(_ bool, startEngine bool, verifyAttestations bool, parentIsAttested bool, isAttested bool) bool {
-		return !startEngine && verifyAttestations && parentIsAttested && !isAttested
+	return c.RequestAttestations.DeriveValueFrom(reactive.NewDerivedVariable4(func(_ bool, startEngine bool, requestAttestations bool, parentIsAttested bool, isAttested bool) bool {
+		return !startEngine && requestAttestations && parentIsAttested && !isAttested
 	}, chain.StartEngine, chain.RequestAttestations, parent.IsAttested, c.IsAttested))
 }
 

pkg/protocol/sybilprotection/sybilprotectionv1/sybilprotection.go

@@ -160,7 +160,7 @@ func (o *SybilProtection) CommitSlot(slot iotago.SlotIndex) (committeeRoot iotag
 		// If the committed slot is `maxCommittableAge` away from the end of the epoch, then register (reuse)
 		// a committee for the next epoch if it hasn't been selected yet.
 		if slot+maxCommittableAge == currentEpochEndSlot {
-			if _, committeeExists := o.seatManager.CommitteeInEpoch(nextEpoch); !committeeExists {
+			if committee, committeeExists := o.seatManager.CommitteeInEpoch(nextEpoch); !committeeExists {
 				// If the committee for the epoch wasn't set before due to finalization of a slot,
 				// we promote the current committee to also serve in the next epoch.
 				committeeAccounts, err := o.reuseCommittee(currentEpoch, nextEpoch)
@@ -169,6 +169,9 @@ func (o *SybilProtection) CommitSlot(slot iotago.SlotIndex) (committeeRoot iotag
 				}
 
 				o.events.CommitteeSelected.Trigger(committeeAccounts, nextEpoch)
+				o.LogDebug("reusing committee", "nextEpoch", nextEpoch, "committeeIDs", committeeAccounts.IDs())
+			} else {
+				o.LogDebug("not reusing committee", "nextEpoch", nextEpoch, "committeeIDs", committee.IDs())
 			}
 		}
 
@@ -230,7 +233,11 @@ func (o *SybilProtection) committeeRoot(targetCommitteeEpoch iotago.EpochIndex)
 		iotago.AccountIDFromBytes,
 	)
 
-	for _, accountID := range committee.IDs() {
+	committeeIDs := committee.IDs()
+
+	o.LogDebug("generating committee root", "committeeIDs", committeeIDs, "epoch", targetCommitteeEpoch)
+
+	for _, accountID := range committeeIDs {
 		if err = committeeTree.Add(accountID); err != nil {
 			return iotago.Identifier{}, ierrors.Wrapf(err, "failed to add account %s to committee tree", accountID)
 		}
@@ -411,13 +418,17 @@ func (o *SybilProtection) selectNewCommittee(slot iotago.SlotIndex) (*account.Se
 		return nil, ierrors.Wrapf(err, "failed to retrieve candidates for epoch %d", nextEpoch)
 	}
 
+	o.LogDebug("selecting new committee", "candidates", candidates.ToSlice(), "slot", slot)
+
 	// If there's no candidate, reuse the current committee.
 	if candidates.Size() == 0 {
 		committee, err := o.reuseCommittee(currentEpoch, nextEpoch)
 		if err != nil {
 			return nil, ierrors.Wrapf(err, "failed to reuse committee (due to no candidates) for epoch %d", nextEpoch)
 		}
 
+		o.LogDebug("candidates empty, reusing committee", "candidates", committee.IDs(), "slot", slot)
+
 		return committee, nil
 	}
 
@@ -445,6 +456,8 @@ func (o *SybilProtection) selectNewCommittee(slot iotago.SlotIndex) (*account.Se
 
 	o.performanceTracker.ClearCandidates()
 
+	o.LogDebug("rotating committee", "candidates", newCommittee.IDs(), "slot", slot)
+
 	return newCommittee, nil
 }