types/events+evidence: emit events + metrics on evidence validation (#7802)

* event: Added Events after evidence validation; evidence: refactored AddEvidence

Added context and Metrics as parameter for the pool constructor

* evidence: pushed event firing into evidence pool and added metrics to represent the size of the evpool

* state: fixed parameters of evpool mock functions

* evidence: added test to confirm events are generated

* Removed obsolete EvidenceEventPublisher interface

* evidence: pool removed error on missing eventbus

CHANGELOG_PENDING.md

@@ -63,6 +63,7 @@ Special thanks to external contributors on this release:
 - [internal/protoio] \#7325 Optimized `MarshalDelimited` by inlining the common case and using a `sync.Pool` in the worst case. (@odeke-em)
 - [consensus] \#6969 remove logic to 'unlock' a locked block.
 - [evidence] \#7700 Evidence messages contain single Evidence instead of EvidenceList (@jmalicevic)
+- [evidence] \#7802 Evidence pool emits events when evidence is validated and updates a metric when the number of evidence in the evidence pool changes. (@jmalicevic)
 - [pubsub] \#7319 Performance improvements for the event query API (@creachadair)
 - [node] \#7521 Define concrete type for seed node implementation (@spacech1mp)
 - [rpc] \#7612 paginate mempool /unconfirmed_txs rpc endpoint (@spacech1mp)

docs/nodes/metrics.md

@@ -40,6 +40,7 @@ The following metrics are available:
 | consensus_fast_syncing                 | gauge     |               | either 0 (not fast syncing) or 1 (syncing)                             |
 | consensus_state_syncing                | gauge     |               | either 0 (not state syncing) or 1 (syncing)                            |
 | consensus_block_size_bytes             | Gauge     |               | Block size in bytes                                                    |
+| evidence_pool_num_evidence             | Gauge     |               | Number of evidence in the evidence pool 
 | p2p_peers                              | Gauge     |               | Number of peers node's connected to                                    |
 | p2p_peer_receive_bytes_total           | counter   | peer_id, chID | number of bytes per channel received from a given peer                 |
 | p2p_peer_send_bytes_total              | counter   | peer_id, chID | number of bytes per channel sent to a given peer                       |

internal/consensus/byzantine_test.go

@@ -90,7 +90,7 @@ func TestByzantinePrevoteEquivocation(t *testing.T) {
 
 			// Make a full instance of the evidence pool
 			evidenceDB := dbm.NewMemDB()
-			evpool, err := evidence.NewPool(logger.With("module", "evidence"), evidenceDB, stateStore, blockStore)
+			evpool, err := evidence.NewPool(logger.With("module", "evidence"), evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 			require.NoError(t, err)
 
 			// Make State
@@ -104,6 +104,7 @@ func TestByzantinePrevoteEquivocation(t *testing.T) {
 			err = eventBus.Start(ctx)
 			require.NoError(t, err)
 			cs.SetEventBus(eventBus)
+			evpool.SetEventBus(eventBus)
 
 			cs.SetTimeoutTicker(tickerFunc())
 

internal/consensus/reactor_test.go

@@ -427,14 +427,15 @@ func TestReactorWithEvidence(t *testing.T) {
 		ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(ctx, 1, defaultTestTime, privVals[vIdx], cfg.ChainID())
 		require.NoError(t, err)
 		evpool := &statemocks.EvidencePool{}
-		evpool.On("CheckEvidence", mock.AnythingOfType("types.EvidenceList")).Return(nil)
+		evpool.On("CheckEvidence", ctx, mock.AnythingOfType("types.EvidenceList")).Return(nil)
 		evpool.On("PendingEvidence", mock.AnythingOfType("int64")).Return([]types.Evidence{
 			ev}, int64(len(ev.Bytes())))
-		evpool.On("Update", mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
+		evpool.On("Update", ctx, mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
 
 		evpool2 := sm.EmptyEvidencePool{}
 
 		blockExec := sm.NewBlockExecutor(stateStore, log.TestingLogger(), proxyAppConnCon, mempool, evpool, blockStore)
+
 		cs := NewState(ctx, logger.With("validator", i, "module", "consensus"),
 			thisConfig.Consensus, state, blockExec, blockStore, mempool, evpool2)
 		cs.SetPrivValidator(ctx, pv)

internal/consensus/state.go

@@ -1432,7 +1432,7 @@ func (cs *State) defaultDoPrevote(ctx context.Context, height int64, round int32
 	}
 
 	// Validate proposal block, from Tendermint's perspective
-	err := cs.blockExec.ValidateBlock(cs.state, cs.ProposalBlock)
+	err := cs.blockExec.ValidateBlock(ctx, cs.state, cs.ProposalBlock)
 	if err != nil {
 		// ProposalBlock is invalid, prevote nil.
 		logger.Error("prevote step: consensus deems this block invalid; prevoting nil",
@@ -1651,7 +1651,7 @@ func (cs *State) enterPrecommit(ctx context.Context, height int64, round int32)
 		logger.Debug("precommit step: +2/3 prevoted proposal block; locking", "hash", blockID.Hash)
 
 		// Validate the block.
-		if err := cs.blockExec.ValidateBlock(cs.state, cs.ProposalBlock); err != nil {
+		if err := cs.blockExec.ValidateBlock(ctx, cs.state, cs.ProposalBlock); err != nil {
 			panic(fmt.Sprintf("precommit step: +2/3 prevoted for an invalid block %v; relocking", err))
 		}
 
@@ -1831,7 +1831,7 @@ func (cs *State) finalizeCommit(ctx context.Context, height int64) {
 		panic("cannot finalize commit; proposal block does not hash to commit hash")
 	}
 
-	if err := cs.blockExec.ValidateBlock(cs.state, block); err != nil {
+	if err := cs.blockExec.ValidateBlock(ctx, cs.state, block); err != nil {
 		panic(fmt.Errorf("+2/3 committed an invalid block: %w", err))
 	}
 

internal/eventbus/event_bus.go

@@ -198,6 +198,10 @@ func (b *EventBus) PublishEventValidatorSetUpdates(ctx context.Context, data typ
 	return b.Publish(ctx, types.EventValidatorSetUpdatesValue, data)
 }
 
+func (b *EventBus) PublishEventEvidenceValidated(ctx context.Context, evidence types.EventDataEvidenceValidated) error {
+	return b.Publish(ctx, types.EventEvidenceValidatedValue, evidence)
+}
+
 //-----------------------------------------------------------------------------
 
 // NopEventBus implements a types.BlockEventPublisher that discards all events.

internal/eventbus/event_bus_test.go

@@ -293,6 +293,48 @@ func TestEventBusPublishEventNewBlockHeader(t *testing.T) {
 	}
 }
 
+func TestEventBusPublishEventEvidenceValidated(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	eventBus := eventbus.NewDefault(log.TestingLogger())
+	err := eventBus.Start(ctx)
+	require.NoError(t, err)
+
+	ev, err := types.NewMockDuplicateVoteEvidence(ctx, 1, time.Now(), "test-chain-id")
+	require.NoError(t, err)
+
+	const query = `tm.event='EvidenceValidated'`
+	evSub, err := eventBus.SubscribeWithArgs(ctx, tmpubsub.SubscribeArgs{
+		ClientID: "test",
+		Query:    tmquery.MustCompile(query),
+	})
+
+	require.NoError(t, err)
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		msg, err := evSub.Next(ctx)
+		assert.NoError(t, err)
+
+		edt := msg.Data().(types.EventDataEvidenceValidated)
+		assert.Equal(t, ev, edt.Evidence)
+		assert.Equal(t, int64(1), edt.Height)
+	}()
+
+	err = eventBus.PublishEventEvidenceValidated(ctx, types.EventDataEvidenceValidated{
+		Evidence: ev,
+		Height:   int64(1),
+	})
+	assert.NoError(t, err)
+
+	select {
+	case <-done:
+	case <-time.After(1 * time.Second):
+		t.Fatal("did not receive a block header after 1 sec.")
+	}
+
+}
 func TestEventBusPublishEventNewEvidence(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()

internal/evidence/metrics.go

@@ -0,0 +1,47 @@
+package evidence
+
+import (
+	"github.com/go-kit/kit/metrics"
+	"github.com/go-kit/kit/metrics/discard"
+	"github.com/go-kit/kit/metrics/prometheus"
+	stdprometheus "github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	// MetricsSubsystem is a subsystem shared by all metrics exposed by this
+	// package.
+	MetricsSubsystem = "evidence_pool"
+)
+
+// Metrics contains metrics exposed by this package.
+// see MetricsProvider for descriptions.
+type Metrics struct {
+	// Number of evidence in the evidence pool
+	NumEvidence metrics.Gauge
+}
+
+// PrometheusMetrics returns Metrics build using Prometheus client library.
+// Optionally, labels can be provided along with their values ("foo",
+// "fooValue").
+func PrometheusMetrics(namespace string, labelsAndValues ...string) *Metrics {
+	labels := []string{}
+	for i := 0; i < len(labelsAndValues); i += 2 {
+		labels = append(labels, labelsAndValues[i])
+	}
+	return &Metrics{
+
+		NumEvidence: prometheus.NewGaugeFrom(stdprometheus.GaugeOpts{
+			Namespace: namespace,
+			Subsystem: MetricsSubsystem,
+			Name:      "num_evidence",
+			Help:      "Number of pending evidence in evidence pool.",
+		}, labels).With(labelsAndValues...),
+	}
+}
+
+// NopMetrics returns no-op Metrics.
+func NopMetrics() *Metrics {
+	return &Metrics{
+		NumEvidence: discard.NewGauge(),
+	}
+}

internal/evidence/pool.go

@@ -2,6 +2,7 @@ package evidence
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"sync"
@@ -13,6 +14,7 @@ import (
 	"github.com/google/orderedcode"
 	dbm "github.com/tendermint/tm-db"
 
+	"github.com/tendermint/tendermint/internal/eventbus"
 	clist "github.com/tendermint/tendermint/internal/libs/clist"
 	sm "github.com/tendermint/tendermint/internal/state"
 	"github.com/tendermint/tendermint/libs/log"
@@ -49,11 +51,22 @@ type Pool struct {
 
 	pruningHeight int64
 	pruningTime   time.Time
+
+	// Eventbus to emit events when evidence is validated
+	// Not part of the constructor, use SetEventBus to set it
+	// The eventBus must be started in order for event publishing not to block
+	eventBus *eventbus.EventBus
+
+	Metrics *Metrics
+}
+
+func (evpool *Pool) SetEventBus(e *eventbus.EventBus) {
+	evpool.eventBus = e
 }
 
 // NewPool creates an evidence pool. If using an existing evidence store,
 // it will add all pending evidence to the concurrent list.
-func NewPool(logger log.Logger, evidenceDB dbm.DB, stateDB sm.Store, blockStore BlockStore) (*Pool, error) {
+func NewPool(logger log.Logger, evidenceDB dbm.DB, stateDB sm.Store, blockStore BlockStore, metrics *Metrics) (*Pool, error) {
 	state, err := stateDB.Load()
 	if err != nil {
 		return nil, fmt.Errorf("failed to load state: %w", err)
@@ -67,6 +80,7 @@ func NewPool(logger log.Logger, evidenceDB dbm.DB, stateDB sm.Store, blockStore
 		evidenceStore:   evidenceDB,
 		evidenceList:    clist.New(),
 		consensusBuffer: make([]duplicateVoteSet, 0),
+		Metrics:         metrics,
 	}
 
 	// If pending evidence already in db, in event of prior failure, then check
@@ -78,10 +92,12 @@ func NewPool(logger log.Logger, evidenceDB dbm.DB, stateDB sm.Store, blockStore
 	}
 
 	atomic.StoreUint32(&pool.evidenceSize, uint32(len(evList)))
+	pool.Metrics.NumEvidence.Set(float64(pool.evidenceSize))
 
 	for _, ev := range evList {
 		pool.evidenceList.PushBack(ev)
 	}
+	pool.eventBus = nil
 
 	return pool, nil
 }
@@ -108,7 +124,7 @@ func (evpool *Pool) PendingEvidence(maxBytes int64) ([]types.Evidence, int64) {
 // 2. Update the pool's state which contains evidence params relating to expiry.
 // 3. Moves pending evidence that has now been committed into the committed pool.
 // 4. Removes any expired evidence based on both height and time.
-func (evpool *Pool) Update(state sm.State, ev types.EvidenceList) {
+func (evpool *Pool) Update(ctx context.Context, state sm.State, ev types.EvidenceList) {
 	// sanity check
 	if state.LastBlockHeight <= evpool.state.LastBlockHeight {
 		panic(fmt.Sprintf(
@@ -126,7 +142,7 @@ func (evpool *Pool) Update(state sm.State, ev types.EvidenceList) {
 
 	// flush conflicting vote pairs from the buffer, producing DuplicateVoteEvidence and
 	// adding it to the pool
-	evpool.processConsensusBuffer(state)
+	evpool.processConsensusBuffer(ctx, state)
 	// update state
 	evpool.updateState(state)
 
@@ -142,7 +158,7 @@ func (evpool *Pool) Update(state sm.State, ev types.EvidenceList) {
 }
 
 // AddEvidence checks the evidence is valid and adds it to the pool.
-func (evpool *Pool) AddEvidence(ev types.Evidence) error {
+func (evpool *Pool) AddEvidence(ctx context.Context, ev types.Evidence) error {
 	evpool.logger.Debug("attempting to add evidence", "evidence", ev)
 
 	// We have already verified this piece of evidence - no need to do it again
@@ -160,12 +176,12 @@ func (evpool *Pool) AddEvidence(ev types.Evidence) error {
 	}
 
 	// 1) Verify against state.
-	if err := evpool.verify(ev); err != nil {
+	if err := evpool.verify(ctx, ev); err != nil {
 		return err
 	}
 
 	// 2) Save to store.
-	if err := evpool.addPendingEvidence(ev); err != nil {
+	if err := evpool.addPendingEvidence(ctx, ev); err != nil {
 		return fmt.Errorf("failed to add evidence to pending list: %w", err)
 	}
 
@@ -198,7 +214,7 @@ func (evpool *Pool) ReportConflictingVotes(voteA, voteB *types.Vote) {
 // If it has already verified the evidence then it jumps to the next one. It ensures that no
 // evidence has already been committed or is being proposed twice. It also adds any
 // evidence that it doesn't currently have so that it can quickly form ABCI Evidence later.
-func (evpool *Pool) CheckEvidence(evList types.EvidenceList) error {
+func (evpool *Pool) CheckEvidence(ctx context.Context, evList types.EvidenceList) error {
 	hashes := make([][]byte, len(evList))
 	for idx, ev := range evList {
 
@@ -212,12 +228,12 @@ func (evpool *Pool) CheckEvidence(evList types.EvidenceList) error {
 				return &types.ErrInvalidEvidence{Evidence: ev, Reason: errors.New("evidence was already committed")}
 			}
 
-			err := evpool.verify(ev)
+			err := evpool.verify(ctx, ev)
 			if err != nil {
 				return err
 			}
 
-			if err := evpool.addPendingEvidence(ev); err != nil {
+			if err := evpool.addPendingEvidence(ctx, ev); err != nil {
 				// Something went wrong with adding the evidence but we already know it is valid
 				// hence we log an error and continue
 				evpool.logger.Error("failed to add evidence to pending list", "err", err, "evidence", ev)
@@ -297,7 +313,7 @@ func (evpool *Pool) isPending(evidence types.Evidence) bool {
 	return ok
 }
 
-func (evpool *Pool) addPendingEvidence(ev types.Evidence) error {
+func (evpool *Pool) addPendingEvidence(ctx context.Context, ev types.Evidence) error {
 	evpb, err := types.EvidenceToProto(ev)
 	if err != nil {
 		return fmt.Errorf("failed to convert to proto: %w", err)
@@ -316,7 +332,18 @@ func (evpool *Pool) addPendingEvidence(ev types.Evidence) error {
 	}
 
 	atomic.AddUint32(&evpool.evidenceSize, 1)
-	return nil
+	evpool.Metrics.NumEvidence.Set(float64(evpool.evidenceSize))
+
+	// This should normally never be true
+	if evpool.eventBus == nil {
+		evpool.logger.Debug("event bus is not configured")
+		return nil
+
+	}
+	return evpool.eventBus.PublishEventEvidenceValidated(ctx, types.EventDataEvidenceValidated{
+		Evidence: ev,
+		Height:   ev.Height(),
+	})
 }
 
 // markEvidenceAsCommitted processes all the evidence in the block, marking it as
@@ -368,6 +395,7 @@ func (evpool *Pool) markEvidenceAsCommitted(evidence types.EvidenceList, height
 
 	// update the evidence size
 	atomic.AddUint32(&evpool.evidenceSize, ^uint32(len(blockEvidenceMap)-1))
+	evpool.Metrics.NumEvidence.Set(float64(evpool.evidenceSize))
 }
 
 // listEvidence retrieves lists evidence from oldest to newest within maxBytes.
@@ -513,7 +541,7 @@ func (evpool *Pool) updateState(state sm.State) {
 // into DuplicateVoteEvidence. It sets the evidence timestamp to the block height
 // from the most recently committed block.
 // Evidence is then added to the pool so as to be ready to be broadcasted and proposed.
-func (evpool *Pool) processConsensusBuffer(state sm.State) {
+func (evpool *Pool) processConsensusBuffer(ctx context.Context, state sm.State) {
 	evpool.mtx.Lock()
 	defer evpool.mtx.Unlock()
 	for _, voteSet := range evpool.consensusBuffer {
@@ -578,7 +606,7 @@ func (evpool *Pool) processConsensusBuffer(state sm.State) {
 			continue
 		}
 
-		if err := evpool.addPendingEvidence(dve); err != nil {
+		if err := evpool.addPendingEvidence(ctx, dve); err != nil {
 			evpool.logger.Error("failed to flush evidence from consensus buffer to pending list: %w", err)
 			continue
 		}

internal/evidence/pool_test.go

@@ -11,6 +11,7 @@ import (
 
 	dbm "github.com/tendermint/tm-db"
 
+	"github.com/tendermint/tendermint/internal/eventbus"
 	"github.com/tendermint/tendermint/internal/evidence"
 	"github.com/tendermint/tendermint/internal/evidence/mocks"
 	sm "github.com/tendermint/tendermint/internal/state"
@@ -21,6 +22,9 @@ import (
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/types"
 	"github.com/tendermint/tendermint/version"
+
+	tmpubsub "github.com/tendermint/tendermint/internal/pubsub"
+	tmquery "github.com/tendermint/tendermint/internal/pubsub/query"
 )
 
 const evidenceChainID = "test_chain"
@@ -40,7 +44,6 @@ func TestEvidencePoolBasic(t *testing.T) {
 
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-
 	valSet, privVals := factory.ValidatorSet(ctx, t, 1, 10)
 	blockStore.On("LoadBlockMeta", mock.AnythingOfType("int64")).Return(
 		&types.BlockMeta{Header: types.Header{Time: defaultEvidenceTime}},
@@ -48,9 +51,9 @@ func TestEvidencePoolBasic(t *testing.T) {
 	stateStore.On("LoadValidators", mock.AnythingOfType("int64")).Return(valSet, nil)
 	stateStore.On("Load").Return(createState(height+1, valSet), nil)
 
-	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
-
+	require.NoError(t, setupEventBus(ctx, pool))
 	// evidence not seen yet:
 	evs, size := pool.PendingEvidence(defaultEvidenceMaxBytes)
 	require.Equal(t, 0, len(evs))
@@ -66,7 +69,8 @@ func TestEvidencePoolBasic(t *testing.T) {
 	}()
 
 	// evidence seen but not yet committed:
-	require.NoError(t, pool.AddEvidence(ev))
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
 
 	select {
 	case <-evAdded:
@@ -83,7 +87,8 @@ func TestEvidencePoolBasic(t *testing.T) {
 	require.Equal(t, evidenceBytes, size) // check that the size of the single evidence in bytes is correct
 
 	// shouldn't be able to add evidence twice
-	require.NoError(t, pool.AddEvidence(ev))
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
 	evs, _ = pool.PendingEvidence(defaultEvidenceMaxBytes)
 	require.Equal(t, 1, len(evs))
 }
@@ -110,9 +115,11 @@ func TestAddExpiredEvidence(t *testing.T) {
 		return &types.BlockMeta{Header: types.Header{Time: expiredEvidenceTime}}
 	})
 
-	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	testCases := []struct {
 		evHeight      int64
 		evTime        time.Time
@@ -136,7 +143,7 @@ func TestAddExpiredEvidence(t *testing.T) {
 
 			ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(ctx, tc.evHeight, tc.evTime, val, evidenceChainID)
 			require.NoError(t, err)
-			err = pool.AddEvidence(ev)
+			err = pool.AddEvidence(ctx, ev)
 			if tc.expErr {
 				require.Error(t, err)
 			} else {
@@ -153,6 +160,9 @@ func TestReportConflictingVotes(t *testing.T) {
 	defer cancel()
 
 	pool, pv := defaultTestPool(ctx, t, height)
+
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	val := types.NewValidator(pv.PrivKey.PubKey(), 10)
 
 	ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(ctx, height+1, defaultEvidenceTime, pv, evidenceChainID)
@@ -176,7 +186,7 @@ func TestReportConflictingVotes(t *testing.T) {
 	state.LastBlockHeight++
 	state.LastBlockTime = ev.Time()
 	state.LastValidators = types.NewValidatorSet([]*types.Validator{val})
-	pool.Update(state, []types.Evidence{})
+	pool.Update(ctx, state, []types.Evidence{})
 
 	// should be able to retrieve evidence from pool
 	evList, _ = pool.PendingEvidence(defaultEvidenceMaxBytes)
@@ -192,6 +202,9 @@ func TestEvidencePoolUpdate(t *testing.T) {
 	defer cancel()
 
 	pool, val := defaultTestPool(ctx, t, height)
+
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	state := pool.State()
 
 	// create two lots of old evidence that we expect to be pruned when we update
@@ -211,8 +224,8 @@ func TestEvidencePoolUpdate(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	require.NoError(t, pool.AddEvidence(prunedEv))
-	require.NoError(t, pool.AddEvidence(notPrunedEv))
+	require.NoError(t, pool.AddEvidence(ctx, prunedEv))
+	require.NoError(t, pool.AddEvidence(ctx, notPrunedEv))
 
 	ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(
 		ctx,
@@ -234,21 +247,21 @@ func TestEvidencePoolUpdate(t *testing.T) {
 
 	require.Equal(t, uint32(2), pool.Size())
 
-	require.NoError(t, pool.CheckEvidence(types.EvidenceList{ev}))
+	require.NoError(t, pool.CheckEvidence(ctx, types.EvidenceList{ev}))
 
 	evList, _ = pool.PendingEvidence(3 * defaultEvidenceMaxBytes)
 	require.Equal(t, 3, len(evList))
 
 	require.Equal(t, uint32(3), pool.Size())
 
-	pool.Update(state, block.Evidence)
+	pool.Update(ctx, state, block.Evidence)
 
 	// a) Update marks evidence as committed so pending evidence should be empty
 	evList, _ = pool.PendingEvidence(defaultEvidenceMaxBytes)
 	require.Equal(t, []types.Evidence{notPrunedEv}, evList)
 
 	// b) If we try to check this evidence again it should fail because it has already been committed
-	err = pool.CheckEvidence(types.EvidenceList{ev})
+	err = pool.CheckEvidence(ctx, types.EvidenceList{ev})
 	if assert.Error(t, err) {
 		assert.Equal(t, "evidence was already committed", err.(*types.ErrInvalidEvidence).Reason.Error())
 	}
@@ -261,6 +274,9 @@ func TestVerifyPendingEvidencePasses(t *testing.T) {
 	defer cancel()
 
 	pool, val := defaultTestPool(ctx, t, height)
+
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(
 		ctx,
 		height,
@@ -269,8 +285,8 @@ func TestVerifyPendingEvidencePasses(t *testing.T) {
 		evidenceChainID,
 	)
 	require.NoError(t, err)
-	require.NoError(t, pool.AddEvidence(ev))
-	require.NoError(t, pool.CheckEvidence(types.EvidenceList{ev}))
+	require.NoError(t, pool.AddEvidence(ctx, ev))
+	require.NoError(t, pool.CheckEvidence(ctx, types.EvidenceList{ev}))
 }
 
 func TestVerifyDuplicatedEvidenceFails(t *testing.T) {
@@ -281,6 +297,32 @@ func TestVerifyDuplicatedEvidenceFails(t *testing.T) {
 
 	pool, val := defaultTestPool(ctx, t, height)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
+	ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(
+		ctx,
+		height,
+		defaultEvidenceTime.Add(1*time.Minute),
+		val,
+		evidenceChainID,
+	)
+
+	require.NoError(t, err)
+	err = pool.CheckEvidence(ctx, types.EvidenceList{ev, ev})
+	if assert.Error(t, err) {
+		assert.Equal(t, "duplicate evidence", err.(*types.ErrInvalidEvidence).Reason.Error())
+	}
+}
+
+// Check that we generate events when evidence is added into the evidence pool
+func TestEventOnEvidenceValidated(t *testing.T) {
+	const height = 1
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	pool, val := defaultTestPool(ctx, t, height)
+
 	ev, err := types.NewMockDuplicateVoteEvidenceWithValidator(
 		ctx,
 		height,
@@ -288,12 +330,38 @@ func TestVerifyDuplicatedEvidenceFails(t *testing.T) {
 		val,
 		evidenceChainID,
 	)
-
 	require.NoError(t, err)
-	err = pool.CheckEvidence(types.EvidenceList{ev, ev})
-	if assert.Error(t, err) {
-		assert.Equal(t, "duplicate evidence", err.(*types.ErrInvalidEvidence).Reason.Error())
+
+	eventBus := eventbus.NewDefault(log.TestingLogger())
+	require.NoError(t, eventBus.Start(ctx))
+
+	pool.SetEventBus(eventBus)
+
+	const query = `tm.event='EvidenceValidated'`
+	evSub, err := eventBus.SubscribeWithArgs(ctx, tmpubsub.SubscribeArgs{
+		ClientID: "test",
+		Query:    tmquery.MustCompile(query),
+	})
+	require.NoError(t, err)
+
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		msg, err := evSub.Next(ctx)
+		assert.NoError(t, err)
+
+		edt := msg.Data().(types.EventDataEvidenceValidated)
+		assert.Equal(t, ev, edt.Evidence)
+	}()
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
+
+	select {
+	case <-done:
+	case <-time.After(1 * time.Second):
+		t.Fatal("did not receive a block header after 1 sec.")
 	}
+
 }
 
 // check that valid light client evidence is correctly validated and stored in
@@ -326,32 +394,38 @@ func TestLightClientAttackEvidenceLifecycle(t *testing.T) {
 	blockStore.On("LoadBlockCommit", height).Return(trusted.Commit)
 	blockStore.On("LoadBlockCommit", commonHeight).Return(common.Commit)
 
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	hash := ev.Hash()
 
-	require.NoError(t, pool.AddEvidence(ev))
-	require.NoError(t, pool.AddEvidence(ev))
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
 
 	pendingEv, _ := pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
 	require.Equal(t, 1, len(pendingEv))
 	require.Equal(t, ev, pendingEv[0])
 
-	require.NoError(t, pool.CheckEvidence(pendingEv))
+	require.NoError(t, pool.CheckEvidence(ctx, pendingEv))
 	require.Equal(t, ev, pendingEv[0])
 
 	state.LastBlockHeight++
 	state.LastBlockTime = state.LastBlockTime.Add(1 * time.Minute)
-	pool.Update(state, pendingEv)
+	pool.Update(ctx, state, pendingEv)
 	require.Equal(t, hash, pendingEv[0].Hash())
 
 	remaindingEv, _ := pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
 	require.Empty(t, remaindingEv)
 
 	// evidence is already committed so it shouldn't pass
-	require.Error(t, pool.CheckEvidence(types.EvidenceList{ev}))
-	require.NoError(t, pool.AddEvidence(ev))
+	require.Error(t, pool.CheckEvidence(ctx, types.EvidenceList{ev}))
+
+	err = pool.AddEvidence(ctx, ev)
+	require.NoError(t, err)
 
 	remaindingEv, _ = pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
 	require.Empty(t, remaindingEv)
@@ -376,9 +450,11 @@ func TestRecoverPendingEvidence(t *testing.T) {
 	require.NoError(t, err)
 
 	// create previous pool and populate it
-	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	goodEvidence, err := types.NewMockDuplicateVoteEvidenceWithValidator(
 		ctx,
 		height,
@@ -396,8 +472,10 @@ func TestRecoverPendingEvidence(t *testing.T) {
 	)
 	require.NoError(t, err)
 
-	require.NoError(t, pool.AddEvidence(goodEvidence))
-	require.NoError(t, pool.AddEvidence(expiredEvidence))
+	err = pool.AddEvidence(ctx, goodEvidence)
+	require.NoError(t, err)
+	err = pool.AddEvidence(ctx, expiredEvidence)
+	require.NoError(t, err)
 
 	// now recover from the previous pool at a different time
 	newStateStore := &smmocks.Store{}
@@ -417,7 +495,7 @@ func TestRecoverPendingEvidence(t *testing.T) {
 		},
 	}, nil)
 
-	newPool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, newStateStore, blockStore)
+	newPool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, newStateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
 	evList, _ := newPool.PendingEvidence(defaultEvidenceMaxBytes)
@@ -523,7 +601,7 @@ func defaultTestPool(ctx context.Context, t *testing.T, height int64) (*evidence
 	blockStore, err := initializeBlockStore(dbm.NewMemDB(), state, valAddress)
 	require.NoError(t, err)
 
-	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err, "test evidence pool could not be created")
 
 	return pool, val
@@ -538,3 +616,12 @@ func createState(height int64, valSet *types.ValidatorSet) sm.State {
 		ConsensusParams: *types.DefaultConsensusParams(),
 	}
 }
+
+func setupEventBus(ctx context.Context, evpool *evidence.Pool) error {
+	eventBus := eventbus.NewDefault(log.TestingLogger())
+	if err := eventBus.Start(ctx); err != nil {
+		return err
+	}
+	evpool.SetEventBus(eventBus)
+	return nil
+}

internal/evidence/reactor.go

@@ -50,7 +50,8 @@ type Reactor struct {
 	evidenceCh  *p2p.Channel
 	peerUpdates *p2p.PeerUpdates
 
-	mtx          sync.Mutex
+	mtx sync.Mutex
+
 	peerRoutines map[types.NodeID]context.CancelFunc
 }
 
@@ -78,6 +79,7 @@ func NewReactor(
 	}
 
 	r.BaseService = *service.NewBaseService(logger, "Evidence", r)
+
 	return r, err
 }
 
@@ -103,7 +105,7 @@ func (r *Reactor) OnStop() {
 // It returns an error only if the Envelope.Message is unknown for this channel
 // or if the given evidence is invalid. This should never be called outside of
 // handleMessage.
-func (r *Reactor) handleEvidenceMessage(envelope *p2p.Envelope) error {
+func (r *Reactor) handleEvidenceMessage(ctx context.Context, envelope *p2p.Envelope) error {
 	logger := r.logger.With("peer", envelope.From)
 
 	switch msg := envelope.Message.(type) {
@@ -115,12 +117,13 @@ func (r *Reactor) handleEvidenceMessage(envelope *p2p.Envelope) error {
 			logger.Error("failed to convert evidence", "err", err)
 			return err
 		}
-		if err := r.evpool.AddEvidence(ev); err != nil {
+		if err := r.evpool.AddEvidence(ctx, ev); err != nil {
 			// If we're given invalid evidence by the peer, notify the router that
 			// we should remove this peer by returning an error.
 			if _, ok := err.(*types.ErrInvalidEvidence); ok {
 				return err
 			}
+
 		}
 
 	default:
@@ -133,7 +136,7 @@ func (r *Reactor) handleEvidenceMessage(envelope *p2p.Envelope) error {
 // handleMessage handles an Envelope sent from a peer on a specific p2p Channel.
 // It will handle errors and any possible panics gracefully. A caller can handle
 // any error returned by sending a PeerError on the respective channel.
-func (r *Reactor) handleMessage(chID p2p.ChannelID, envelope *p2p.Envelope) (err error) {
+func (r *Reactor) handleMessage(ctx context.Context, chID p2p.ChannelID, envelope *p2p.Envelope) (err error) {
 	defer func() {
 		if e := recover(); e != nil {
 			err = fmt.Errorf("panic in processing message: %v", e)
@@ -149,7 +152,7 @@ func (r *Reactor) handleMessage(chID p2p.ChannelID, envelope *p2p.Envelope) (err
 
 	switch chID {
 	case EvidenceChannel:
-		err = r.handleEvidenceMessage(envelope)
+		err = r.handleEvidenceMessage(ctx, envelope)
 
 	default:
 		err = fmt.Errorf("unknown channel ID (%d) for envelope (%v)", chID, envelope)
@@ -164,7 +167,7 @@ func (r *Reactor) processEvidenceCh(ctx context.Context) {
 	iter := r.evidenceCh.Receive(ctx)
 	for iter.Next(ctx) {
 		envelope := iter.Envelope()
-		if err := r.handleMessage(r.evidenceCh.ID, envelope); err != nil {
+		if err := r.handleMessage(ctx, r.evidenceCh.ID, envelope); err != nil {
 			r.logger.Error("failed to process message", "ch_id", r.evidenceCh.ID, "envelope", envelope, "err", err)
 			if serr := r.evidenceCh.SendError(ctx, p2p.PeerError{
 				NodeID: envelope.From,

internal/evidence/reactor_test.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/crypto/tmhash"
+	"github.com/tendermint/tendermint/internal/eventbus"
 	"github.com/tendermint/tendermint/internal/evidence"
 	"github.com/tendermint/tendermint/internal/evidence/mocks"
 	"github.com/tendermint/tendermint/internal/p2p"
@@ -69,6 +70,7 @@ func setup(ctx context.Context, t *testing.T, stateStores []sm.Store, chBuf uint
 
 	idx := 0
 	evidenceTime := time.Date(2019, 1, 1, 0, 0, 0, 0, time.UTC)
+
 	for nodeID := range rts.network.Nodes {
 		logger := rts.logger.With("validator", idx)
 		evidenceDB := dbm.NewMemDB()
@@ -80,9 +82,13 @@ func setup(ctx context.Context, t *testing.T, stateStores []sm.Store, chBuf uint
 			}
 			return nil
 		})
-		rts.pools[nodeID], err = evidence.NewPool(logger, evidenceDB, stateStores[idx], blockStore)
+		rts.pools[nodeID], err = evidence.NewPool(logger, evidenceDB, stateStores[idx], blockStore, evidence.NopMetrics())
 
 		require.NoError(t, err)
+		eventBus := eventbus.NewDefault(logger)
+		err = eventBus.Start(ctx)
+		require.NoError(t, err)
+		rts.pools[nodeID].SetEventBus(eventBus)
 
 		rts.peerChans[nodeID] = make(chan p2p.PeerUpdate)
 		rts.peerUpdates[nodeID] = p2p.NewPeerUpdates(rts.peerChans[nodeID], 1)
@@ -219,7 +225,8 @@ func createEvidenceList(
 			evidenceChainID,
 		)
 		require.NoError(t, err)
-		require.NoError(t, pool.AddEvidence(ev),
+		err = pool.AddEvidence(ctx, ev)
+		require.NoError(t, err,
 			"adding evidence it#%d of %d to pool with height %d",
 			i, numEvidence, pool.State().LastBlockHeight)
 		evList[i] = ev
@@ -284,12 +291,14 @@ func TestReactorBroadcastEvidence(t *testing.T) {
 	}
 
 	rts := setup(ctx, t, stateDBs, 0)
+
 	rts.start(ctx, t)
 
 	// Create a series of fixtures where each suite contains a reactor and
 	// evidence pool. In addition, we mark a primary suite and the rest are
 	// secondaries where each secondary is added as a peer via a PeerUpdate to the
 	// primary. As a result, the primary will gossip all evidence to each secondary.
+
 	primary := rts.network.RandomNode()
 	secondaries := make([]*p2ptest.Node, 0, len(rts.network.NodeIDs())-1)
 	secondaryIDs := make([]types.NodeID, 0, cap(secondaries))
@@ -320,6 +329,7 @@ func TestReactorBroadcastEvidence(t *testing.T) {
 	for _, pool := range rts.pools {
 		require.Equal(t, numEvidence, int(pool.Size()))
 	}
+
 }
 
 // TestReactorSelectiveBroadcast tests a context where we have two reactors
@@ -381,7 +391,8 @@ func TestReactorBroadcastEvidence_Pending(t *testing.T) {
 	// Manually add half the evidence to the secondary which will mark them as
 	// pending.
 	for i := 0; i < numEvidence/2; i++ {
-		require.NoError(t, rts.pools[secondary.NodeID].AddEvidence(evList[i]))
+		err := rts.pools[secondary.NodeID].AddEvidence(ctx, evList[i])
+		require.NoError(t, err)
 	}
 
 	// the secondary should have half the evidence as pending
@@ -423,7 +434,8 @@ func TestReactorBroadcastEvidence_Committed(t *testing.T) {
 	// Manually add half the evidence to the secondary which will mark them as
 	// pending.
 	for i := 0; i < numEvidence/2; i++ {
-		require.NoError(t, rts.pools[secondary.NodeID].AddEvidence(evList[i]))
+		err := rts.pools[secondary.NodeID].AddEvidence(ctx, evList[i])
+		require.NoError(t, err)
 	}
 
 	// the secondary should have half the evidence as pending
@@ -434,7 +446,7 @@ func TestReactorBroadcastEvidence_Committed(t *testing.T) {
 
 	// update the secondary's pool such that all pending evidence is committed
 	state.LastBlockHeight++
-	rts.pools[secondary.NodeID].Update(state, evList[:numEvidence/2])
+	rts.pools[secondary.NodeID].Update(ctx, state, evList[:numEvidence/2])
 
 	// the secondary should have half the evidence as committed
 	require.Equal(t, 0, int(rts.pools[secondary.NodeID].Size()))
@@ -496,7 +508,7 @@ func TestReactorBroadcastEvidence_FullyConnected(t *testing.T) {
 		// commit state so we do not continue to repeat gossiping the same evidence
 		state := pool.State()
 		state.LastBlockHeight++
-		pool.Update(state, evList)
+		pool.Update(ctx, state, evList)
 	}
 }
 

internal/evidence/verify.go

@@ -2,6 +2,7 @@ package evidence
 
 import (
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"time"
@@ -21,7 +22,7 @@ import (
 // set for. In these cases, we do not return a ErrInvalidEvidence as not to have
 // the sending peer disconnect. All other errors are treated as invalid evidence
 // (i.e. ErrInvalidEvidence).
-func (evpool *Pool) verify(evidence types.Evidence) error {
+func (evpool *Pool) verify(ctx context.Context, evidence types.Evidence) error {
 	var (
 		state          = evpool.State()
 		height         = state.LastBlockHeight
@@ -74,7 +75,7 @@ func (evpool *Pool) verify(evidence types.Evidence) error {
 
 		if err := ev.ValidateABCI(val, valSet, evTime); err != nil {
 			ev.GenerateABCI(val, valSet, evTime)
-			if addErr := evpool.addPendingEvidence(ev); addErr != nil {
+			if addErr := evpool.addPendingEvidence(ctx, ev); addErr != nil {
 				evpool.logger.Error("adding pending duplicate vote evidence failed", "err", addErr)
 			}
 			return err
@@ -134,7 +135,7 @@ func (evpool *Pool) verify(evidence types.Evidence) error {
 		// evidence and return an error
 		if err := ev.ValidateABCI(commonVals, trustedHeader, evTime); err != nil {
 			ev.GenerateABCI(commonVals, trustedHeader, evTime)
-			if addErr := evpool.addPendingEvidence(ev); addErr != nil {
+			if addErr := evpool.addPendingEvidence(ctx, ev); addErr != nil {
 				evpool.logger.Error("adding pending light client attack evidence failed", "err", addErr)
 			}
 			return err

internal/evidence/verify_test.go

@@ -96,12 +96,12 @@ func TestVerify_LunaticAttackAgainstState(t *testing.T) {
 	blockStore.On("LoadBlockMeta", height).Return(&types.BlockMeta{Header: *trusted.Header})
 	blockStore.On("LoadBlockCommit", commonHeight).Return(common.Commit)
 	blockStore.On("LoadBlockCommit", height).Return(trusted.Commit)
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
 	evList := types.EvidenceList{ev}
 	// check that the evidence pool correctly verifies the evidence
-	assert.NoError(t, pool.CheckEvidence(evList))
+	assert.NoError(t, pool.CheckEvidence(ctx, evList))
 
 	// as it was not originally in the pending bucket, it should now have been added
 	pendingEvs, _ := pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
@@ -112,28 +112,33 @@ func TestVerify_LunaticAttackAgainstState(t *testing.T) {
 	// should return an error
 	ev.ByzantineValidators = ev.ByzantineValidators[:1]
 	t.Log(evList)
-	assert.Error(t, pool.CheckEvidence(evList))
+	assert.Error(t, pool.CheckEvidence(ctx, evList))
 	// restore original byz vals
 	ev.ByzantineValidators = ev.GetByzantineValidators(common.ValidatorSet, trusted.SignedHeader)
 
 	// duplicate evidence should be rejected
 	evList = types.EvidenceList{ev, ev}
-	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
-	assert.Error(t, pool.CheckEvidence(evList))
+	assert.Error(t, pool.CheckEvidence(ctx, evList))
 
 	// If evidence is submitted with an altered timestamp it should return an error
 	ev.Timestamp = defaultEvidenceTime.Add(1 * time.Minute)
-	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
-	assert.Error(t, pool.AddEvidence(ev))
+
+	require.NoError(t, setupEventBus(ctx, pool))
+
+	err = pool.AddEvidence(ctx, ev)
+	assert.Error(t, err)
 	ev.Timestamp = defaultEvidenceTime
 
 	// Evidence submitted with a different validator power should fail
 	ev.TotalVotingPower = 1
-	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
-	assert.Error(t, pool.AddEvidence(ev))
+	err = pool.AddEvidence(ctx, ev)
+	assert.Error(t, err)
 	ev.TotalVotingPower = common.ValidatorSet.TotalVotingPower()
 }
 
@@ -174,11 +179,13 @@ func TestVerify_ForwardLunaticAttack(t *testing.T) {
 	blockStore.On("LoadBlockCommit", commonHeight).Return(common.Commit)
 	blockStore.On("LoadBlockCommit", nodeHeight).Return(trusted.Commit)
 	blockStore.On("Height").Return(nodeHeight)
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	// check that the evidence pool correctly verifies the evidence
-	assert.NoError(t, pool.CheckEvidence(types.EvidenceList{ev}))
+	assert.NoError(t, pool.CheckEvidence(ctx, types.EvidenceList{ev}))
 
 	// now we use a time which isn't able to contradict the FLA - thus we can't verify the evidence
 	oldBlockStore := &mocks.BlockStore{}
@@ -192,9 +199,9 @@ func TestVerify_ForwardLunaticAttack(t *testing.T) {
 	oldBlockStore.On("Height").Return(nodeHeight)
 	require.Equal(t, defaultEvidenceTime, oldBlockStore.LoadBlockMeta(nodeHeight).Header.Time)
 
-	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, oldBlockStore)
+	pool, err = evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, oldBlockStore, evidence.NopMetrics())
 	require.NoError(t, err)
-	assert.Error(t, pool.CheckEvidence(types.EvidenceList{ev}))
+	assert.Error(t, pool.CheckEvidence(ctx, types.EvidenceList{ev}))
 }
 
 func TestVerifyLightClientAttack_Equivocation(t *testing.T) {
@@ -282,11 +289,13 @@ func TestVerifyLightClientAttack_Equivocation(t *testing.T) {
 	blockStore.On("LoadBlockMeta", int64(10)).Return(&types.BlockMeta{Header: *trustedHeader})
 	blockStore.On("LoadBlockCommit", int64(10)).Return(trustedCommit)
 
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	evList := types.EvidenceList{ev}
-	err = pool.CheckEvidence(evList)
+	err = pool.CheckEvidence(ctx, evList)
 	assert.NoError(t, err)
 
 	pendingEvs, _ := pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
@@ -369,11 +378,13 @@ func TestVerifyLightClientAttack_Amnesia(t *testing.T) {
 	blockStore.On("LoadBlockMeta", int64(10)).Return(&types.BlockMeta{Header: *trustedHeader})
 	blockStore.On("LoadBlockCommit", int64(10)).Return(trustedCommit)
 
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	evList := types.EvidenceList{ev}
-	err = pool.CheckEvidence(evList)
+	err = pool.CheckEvidence(ctx, evList)
 	assert.NoError(t, err)
 
 	pendingEvs, _ := pool.PendingEvidence(state.ConsensusParams.Evidence.MaxBytes)
@@ -467,21 +478,23 @@ func TestVerifyDuplicateVoteEvidence(t *testing.T) {
 	blockStore := &mocks.BlockStore{}
 	blockStore.On("LoadBlockMeta", int64(10)).Return(&types.BlockMeta{Header: types.Header{Time: defaultEvidenceTime}})
 
-	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore)
+	pool, err := evidence.NewPool(log.TestingLogger(), dbm.NewMemDB(), stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
+	require.NoError(t, setupEventBus(ctx, pool))
+
 	evList := types.EvidenceList{goodEv}
-	err = pool.CheckEvidence(evList)
+	err = pool.CheckEvidence(ctx, evList)
 	assert.NoError(t, err)
 
 	// evidence with a different validator power should fail
 	evList = types.EvidenceList{badEv}
-	err = pool.CheckEvidence(evList)
+	err = pool.CheckEvidence(ctx, evList)
 	assert.Error(t, err)
 
 	// evidence with a different timestamp should fail
 	evList = types.EvidenceList{badTimeEv}
-	err = pool.CheckEvidence(evList)
+	err = pool.CheckEvidence(ctx, evList)
 	assert.Error(t, err)
 }
 

internal/rpc/core/evidence.go

@@ -19,7 +19,7 @@ func (env *Environment) BroadcastEvidence(
 	if err := ev.Value.ValidateBasic(); err != nil {
 		return nil, fmt.Errorf("evidence.ValidateBasic failed: %w", err)
 	}
-	if err := env.EvidencePool.AddEvidence(ev.Value); err != nil {
+	if err := env.EvidencePool.AddEvidence(ctx, ev.Value); err != nil {
 		return nil, fmt.Errorf("failed to add evidence: %w", err)
 	}
 	return &coretypes.ResultBroadcastEvidence{Hash: ev.Value.Hash()}, nil

internal/state/execution.go

@@ -174,7 +174,7 @@ func (blockExec *BlockExecutor) ProcessProposal(
 // If the block is invalid, it returns an error.
 // Validation does not mutate state, but does require historical information from the stateDB,
 // ie. to verify evidence from a validator at an old height.
-func (blockExec *BlockExecutor) ValidateBlock(state State, block *types.Block) error {
+func (blockExec *BlockExecutor) ValidateBlock(ctx context.Context, state State, block *types.Block) error {
 	hash := block.Hash()
 	if _, ok := blockExec.cache[hash.String()]; ok {
 		return nil
@@ -185,7 +185,7 @@ func (blockExec *BlockExecutor) ValidateBlock(state State, block *types.Block) e
 		return err
 	}
 
-	err = blockExec.evpool.CheckEvidence(block.Evidence)
+	err = blockExec.evpool.CheckEvidence(ctx, block.Evidence)
 	if err != nil {
 		return err
 	}
@@ -208,7 +208,7 @@ func (blockExec *BlockExecutor) ApplyBlock(
 ) (State, error) {
 
 	// validate the block if we haven't already
-	if err := blockExec.ValidateBlock(state, block); err != nil {
+	if err := blockExec.ValidateBlock(ctx, state, block); err != nil {
 		return state, ErrInvalidBlock(err)
 	}
 
@@ -255,7 +255,7 @@ func (blockExec *BlockExecutor) ApplyBlock(
 	}
 
 	// Update evpool with the latest state.
-	blockExec.evpool.Update(state, block.Evidence)
+	blockExec.evpool.Update(ctx, state, block.Evidence)
 
 	// Update the app hash and save the state.
 	state.AppHash = appHash

internal/state/execution_test.go

@@ -216,8 +216,8 @@ func TestBeginBlockByzantineValidators(t *testing.T) {
 
 	evpool := &mocks.EvidencePool{}
 	evpool.On("PendingEvidence", mock.AnythingOfType("int64")).Return(ev, int64(100))
-	evpool.On("Update", mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
-	evpool.On("CheckEvidence", mock.AnythingOfType("types.EvidenceList")).Return(nil)
+	evpool.On("Update", ctx, mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
+	evpool.On("CheckEvidence", ctx, mock.AnythingOfType("types.EvidenceList")).Return(nil)
 
 	blockStore := store.NewBlockStore(dbm.NewMemDB())
 

internal/state/helpers_test.go

@@ -75,7 +75,7 @@ func makeAndApplyGoodBlock(
 	block, _, err := state.MakeBlock(height, factory.MakeTenTxs(height), lastCommit, evidence, proposerAddr)
 	require.NoError(t, err)
 
-	require.NoError(t, blockExec.ValidateBlock(state, block))
+	require.NoError(t, blockExec.ValidateBlock(ctx, state, block))
 	blockID := types.BlockID{Hash: block.Hash(),
 		PartSetHeader: types.PartSetHeader{Total: 3, Hash: tmrand.Bytes(32)}}
 	state, err = blockExec.ApplyBlock(ctx, state, blockID, block)

internal/state/mocks/evidence_pool.go

@@ -3,8 +3,11 @@
 package mocks
 
 import (
+	context "context"
+
 	mock "github.com/stretchr/testify/mock"
 	state "github.com/tendermint/tendermint/internal/state"
+
 	types "github.com/tendermint/tendermint/types"
 )
 
@@ -13,13 +16,13 @@ type EvidencePool struct {
 	mock.Mock
 }
 
-// AddEvidence provides a mock function with given fields: _a0
-func (_m *EvidencePool) AddEvidence(_a0 types.Evidence) error {
-	ret := _m.Called(_a0)
+// AddEvidence provides a mock function with given fields: _a0, _a1
+func (_m *EvidencePool) AddEvidence(_a0 context.Context, _a1 types.Evidence) error {
+	ret := _m.Called(_a0, _a1)
 
 	var r0 error
-	if rf, ok := ret.Get(0).(func(types.Evidence) error); ok {
-		r0 = rf(_a0)
+	if rf, ok := ret.Get(0).(func(context.Context, types.Evidence) error); ok {
+		r0 = rf(_a0, _a1)
 	} else {
 		r0 = ret.Error(0)
 	}
@@ -27,13 +30,13 @@ func (_m *EvidencePool) AddEvidence(_a0 types.Evidence) error {
 	return r0
 }
 
-// CheckEvidence provides a mock function with given fields: _a0
-func (_m *EvidencePool) CheckEvidence(_a0 types.EvidenceList) error {
-	ret := _m.Called(_a0)
+// CheckEvidence provides a mock function with given fields: _a0, _a1
+func (_m *EvidencePool) CheckEvidence(_a0 context.Context, _a1 types.EvidenceList) error {
+	ret := _m.Called(_a0, _a1)
 
 	var r0 error
-	if rf, ok := ret.Get(0).(func(types.EvidenceList) error); ok {
-		r0 = rf(_a0)
+	if rf, ok := ret.Get(0).(func(context.Context, types.EvidenceList) error); ok {
+		r0 = rf(_a0, _a1)
 	} else {
 		r0 = ret.Error(0)
 	}
@@ -64,7 +67,7 @@ func (_m *EvidencePool) PendingEvidence(maxBytes int64) ([]types.Evidence, int64
 	return r0, r1
 }
 
-// Update provides a mock function with given fields: _a0, _a1
-func (_m *EvidencePool) Update(_a0 state.State, _a1 types.EvidenceList) {
-	_m.Called(_a0, _a1)
+// Update provides a mock function with given fields: _a0, _a1, _a2
+func (_m *EvidencePool) Update(_a0 context.Context, _a1 state.State, _a2 types.EvidenceList) {
+	_m.Called(_a0, _a1, _a2)
 }

internal/state/services.go

@@ -1,6 +1,8 @@
 package state
 
 import (
+	"context"
+
 	"github.com/tendermint/tendermint/types"
 )
 
@@ -44,9 +46,9 @@ type BlockStore interface {
 // EvidencePool defines the EvidencePool interface used by State.
 type EvidencePool interface {
 	PendingEvidence(maxBytes int64) (ev []types.Evidence, size int64)
-	AddEvidence(types.Evidence) error
-	Update(State, types.EvidenceList)
-	CheckEvidence(types.EvidenceList) error
+	AddEvidence(context.Context, types.Evidence) error
+	Update(context.Context, State, types.EvidenceList)
+	CheckEvidence(context.Context, types.EvidenceList) error
 }
 
 // EmptyEvidencePool is an empty implementation of EvidencePool, useful for testing. It also complies
@@ -56,7 +58,9 @@ type EmptyEvidencePool struct{}
 func (EmptyEvidencePool) PendingEvidence(maxBytes int64) (ev []types.Evidence, size int64) {
 	return nil, 0
 }
-func (EmptyEvidencePool) AddEvidence(types.Evidence) error                { return nil }
-func (EmptyEvidencePool) Update(State, types.EvidenceList)                {}
-func (EmptyEvidencePool) CheckEvidence(evList types.EvidenceList) error   { return nil }
+func (EmptyEvidencePool) AddEvidence(context.Context, types.Evidence) error { return nil }
+func (EmptyEvidencePool) Update(context.Context, State, types.EvidenceList) {}
+func (EmptyEvidencePool) CheckEvidence(ctx context.Context, evList types.EvidenceList) error {
+	return nil
+}
 func (EmptyEvidencePool) ReportConflictingVotes(voteA, voteB *types.Vote) {}

internal/state/validation_test.go

@@ -94,7 +94,7 @@ func TestValidateBlockHeader(t *testing.T) {
 			block, err := statefactory.MakeBlock(state, height, lastCommit)
 			require.NoError(t, err)
 			tc.malleateBlock(block)
-			err = blockExec.ValidateBlock(state, block)
+			err = blockExec.ValidateBlock(ctx, state, block)
 			t.Logf("%s: %v", tc.name, err)
 			require.Error(t, err, tc.name)
 		}
@@ -110,7 +110,7 @@ func TestValidateBlockHeader(t *testing.T) {
 	block, err := statefactory.MakeBlock(state, nextHeight, lastCommit)
 	require.NoError(t, err)
 	state.InitialHeight = nextHeight + 1
-	err = blockExec.ValidateBlock(state, block)
+	err = blockExec.ValidateBlock(ctx, state, block)
 	require.Error(t, err, "expected an error when state is ahead of block")
 	assert.Contains(t, err.Error(), "lower than initial height")
 }
@@ -164,7 +164,7 @@ func TestValidateBlockCommit(t *testing.T) {
 			)
 			block, err := statefactory.MakeBlock(state, height, wrongHeightCommit)
 			require.NoError(t, err)
-			err = blockExec.ValidateBlock(state, block)
+			err = blockExec.ValidateBlock(ctx, state, block)
 			_, isErrInvalidCommitHeight := err.(types.ErrInvalidCommitHeight)
 			require.True(t, isErrInvalidCommitHeight, "expected ErrInvalidCommitHeight at height %d but got: %v", height, err)
 
@@ -173,7 +173,7 @@ func TestValidateBlockCommit(t *testing.T) {
 			*/
 			block, err = statefactory.MakeBlock(state, height, wrongSigsCommit)
 			require.NoError(t, err)
-			err = blockExec.ValidateBlock(state, block)
+			err = blockExec.ValidateBlock(ctx, state, block)
 			_, isErrInvalidCommitSignatures := err.(types.ErrInvalidCommitSignatures)
 			require.True(t, isErrInvalidCommitSignatures,
 				"expected ErrInvalidCommitSignatures at height %d, but got: %v",
@@ -254,8 +254,8 @@ func TestValidateBlockEvidence(t *testing.T) {
 	defaultEvidenceTime := time.Date(2019, 1, 1, 0, 0, 0, 0, time.UTC)
 
 	evpool := &mocks.EvidencePool{}
-	evpool.On("CheckEvidence", mock.AnythingOfType("types.EvidenceList")).Return(nil)
-	evpool.On("Update", mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
+	evpool.On("CheckEvidence", ctx, mock.AnythingOfType("types.EvidenceList")).Return(nil)
+	evpool.On("Update", ctx, mock.AnythingOfType("state.State"), mock.AnythingOfType("types.EvidenceList")).Return()
 	evpool.On("ABCIEvidence", mock.AnythingOfType("int64"), mock.AnythingOfType("[]types.Evidence")).Return(
 		[]abci.Evidence{})
 
@@ -290,7 +290,7 @@ func TestValidateBlockEvidence(t *testing.T) {
 			block, _, err := state.MakeBlock(height, testfactory.MakeTenTxs(height), lastCommit, evidence, proposerAddr)
 			require.NoError(t, err)
 
-			err = blockExec.ValidateBlock(state, block)
+			err = blockExec.ValidateBlock(ctx, state, block)
 			if assert.Error(t, err) {
 				_, ok := err.(*types.ErrEvidenceOverflow)
 				require.True(t, ok, "expected error to be of type ErrEvidenceOverflow at height %d but got %v", height, err)

node/node.go

@@ -20,6 +20,7 @@ import (
 	"github.com/tendermint/tendermint/internal/blocksync"
 	"github.com/tendermint/tendermint/internal/consensus"
 	"github.com/tendermint/tendermint/internal/eventbus"
+	"github.com/tendermint/tendermint/internal/evidence"
 	"github.com/tendermint/tendermint/internal/mempool"
 	"github.com/tendermint/tendermint/internal/p2p"
 	"github.com/tendermint/tendermint/internal/p2p/pex"
@@ -264,7 +265,7 @@ func makeNode(
 	}
 
 	evReactor, evPool, err := createEvidenceReactor(ctx,
-		cfg, dbProvider, stateDB, blockStore, peerManager, router, logger,
+		cfg, dbProvider, stateDB, blockStore, peerManager, router, logger, nodeMetrics.evidence, eventBus,
 	)
 	if err != nil {
 		return nil, combineCloseError(err, makeCloser(closers))
@@ -689,6 +690,7 @@ type nodeMetrics struct {
 	proxy     *proxy.Metrics
 	state     *sm.Metrics
 	statesync *statesync.Metrics
+	evidence  *evidence.Metrics
 }
 
 // metricsProvider returns consensus, p2p, mempool, state, statesync Metrics.
@@ -707,6 +709,7 @@ func defaultMetricsProvider(cfg *config.InstrumentationConfig) metricsProvider {
 				proxy:     proxy.PrometheusMetrics(cfg.Namespace, "chain_id", chainID),
 				state:     sm.PrometheusMetrics(cfg.Namespace, "chain_id", chainID),
 				statesync: statesync.PrometheusMetrics(cfg.Namespace, "chain_id", chainID),
+				evidence:  evidence.PrometheusMetrics(cfg.Namespace, "chain_id", chainID),
 			}
 		}
 		return &nodeMetrics{
@@ -717,6 +720,7 @@ func defaultMetricsProvider(cfg *config.InstrumentationConfig) metricsProvider {
 			proxy:     proxy.NopMetrics(),
 			state:     sm.NopMetrics(),
 			statesync: statesync.NopMetrics(),
+			evidence:  evidence.NopMetrics(),
 		}
 	}
 }

node/node_test.go

@@ -298,7 +298,7 @@ func TestCreateProposalBlock(t *testing.T) {
 	// Make EvidencePool
 	evidenceDB := dbm.NewMemDB()
 	blockStore := store.NewBlockStore(dbm.NewMemDB())
-	evidencePool, err := evidence.NewPool(logger, evidenceDB, stateStore, blockStore)
+	evidencePool, err := evidence.NewPool(logger, evidenceDB, stateStore, blockStore, evidence.NopMetrics())
 	require.NoError(t, err)
 
 	// fill the evidence pool with more evidence
@@ -357,7 +357,7 @@ func TestCreateProposalBlock(t *testing.T) {
 	}
 	assert.EqualValues(t, partSetFromHeader.ByteSize(), partSet.ByteSize())
 
-	err = blockExec.ValidateBlock(state, block)
+	err = blockExec.ValidateBlock(ctx, state, block)
 	assert.NoError(t, err)
 }
 

node/setup.go

@@ -219,6 +219,8 @@ func createEvidenceReactor(
 	peerManager *p2p.PeerManager,
 	router *p2p.Router,
 	logger log.Logger,
+	metrics *evidence.Metrics,
+	eventBus *eventbus.EventBus,
 ) (*evidence.Reactor, *evidence.Pool, error) {
 	evidenceDB, err := dbProvider(&config.DBContext{ID: "evidence", Config: cfg})
 	if err != nil {
@@ -227,11 +229,13 @@ func createEvidenceReactor(
 
 	logger = logger.With("module", "evidence")
 
-	evidencePool, err := evidence.NewPool(logger, evidenceDB, sm.NewStore(stateDB), blockStore)
+	evidencePool, err := evidence.NewPool(logger, evidenceDB, sm.NewStore(stateDB), blockStore, metrics)
 	if err != nil {
 		return nil, nil, fmt.Errorf("creating evidence pool: %w", err)
 	}
 
+	evidencePool.SetEventBus(eventBus)
+
 	evidenceReactor, err := evidence.NewReactor(
 		ctx,
 		logger,
@@ -295,7 +299,6 @@ func createConsensusReactor(
 	// Services which will be publishing and/or subscribing for messages (events)
 	// consensusReactor will set it on consensusState and blockExecutor.
 	reactor.SetEventBus(eventBus)
-
 	return reactor, consensusState, nil
 }
 

types/events.go

@@ -40,6 +40,10 @@ const (
 	EventTimeoutWaitValue     = "TimeoutWait"
 	EventValidBlockValue      = "ValidBlock"
 	EventVoteValue            = "Vote"
+
+	// Events emitted by the evidence reactor when evidence is validated
+	// and before it is committed
+	EventEvidenceValidatedValue = "EvidenceValidated"
 )
 
 // Pre-populated ABCI Tendermint-reserved events
@@ -104,6 +108,7 @@ func init() {
 	jsontypes.MustRegister(EventDataTx{})
 	jsontypes.MustRegister(EventDataValidatorSetUpdates{})
 	jsontypes.MustRegister(EventDataVote{})
+	jsontypes.MustRegister(EventDataEvidenceValidated{})
 	jsontypes.MustRegister(EventDataString(""))
 }
 
@@ -223,6 +228,15 @@ type EventDataStateSyncStatus struct {
 // TypeTag implements the required method of jsontypes.Tagged.
 func (EventDataStateSyncStatus) TypeTag() string { return "tendermint/event/StateSyncStatus" }
 
+type EventDataEvidenceValidated struct {
+	Evidence Evidence `json:"evidence"`
+
+	Height int64 `json:"height,string"`
+}
+
+// TypeTag implements the required method of jsontypes.Tagged.
+func (EventDataEvidenceValidated) TypeTag() string { return "tendermint/event/EvidenceValidated" }
+
 // PUBSUB
 
 const (
@@ -261,6 +275,7 @@ var (
 	EventQueryVote                = QueryForEvent(EventVoteValue)
 	EventQueryBlockSyncStatus     = QueryForEvent(EventBlockSyncStatusValue)
 	EventQueryStateSyncStatus     = QueryForEvent(EventStateSyncStatusValue)
+	EventQueryEvidenceValidated   = QueryForEvent(EventEvidenceValidatedValue)
 )
 
 func EventQueryTxFor(tx Tx) *tmquery.Query {