ethstats: report newPayload processing time to stats server (#33395)

Add NewPayloadEvent to track engine API newPayload block processing
times and report them to ethstats. This enables monitoring of block
processing performance.

https://notes.ethereum.org/@savid/block-observability

related: https://github.com/ethereum/go-ethereum/pull/33231

---------

Co-authored-by: MariusVanDerWijden <m.vanderwijden@live.de>

core/blockchain.go

@@ -311,6 +311,7 @@ type BlockChain struct {
 	chainHeadFeed    event.Feed
 	logsFeed         event.Feed
 	blockProcFeed    event.Feed
+	newPayloadFeed   event.Feed // Feed for engine API newPayload events
 	blockProcCounter int32
 	scope            event.SubscriptionScope
 	genesisBlock     *types.Block

core/blockchain_reader.go

@@ -522,3 +522,13 @@ func (bc *BlockChain) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscript
 func (bc *BlockChain) SubscribeBlockProcessingEvent(ch chan<- bool) event.Subscription {
 	return bc.scope.Track(bc.blockProcFeed.Subscribe(ch))
 }
+
+// SubscribeNewPayloadEvent registers a subscription for NewPayloadEvent.
+func (bc *BlockChain) SubscribeNewPayloadEvent(ch chan<- NewPayloadEvent) event.Subscription {
+	return bc.scope.Track(bc.newPayloadFeed.Subscribe(ch))
+}
+
+// SendNewPayloadEvent sends a NewPayloadEvent to subscribers.
+func (bc *BlockChain) SendNewPayloadEvent(ev NewPayloadEvent) {
+	bc.newPayloadFeed.Send(ev)
+}

core/events.go

@@ -17,6 +17,9 @@
 package core
 
 import (
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
@@ -35,3 +38,10 @@ type ChainEvent struct {
 type ChainHeadEvent struct {
 	Header *types.Header
 }
+
+// NewPayloadEvent is posted when engine_newPayloadVX processes a block.
+type NewPayloadEvent struct {
+	Hash           common.Hash
+	Number         uint64
+	ProcessingTime time.Duration
+}

eth/api_backend.go

@@ -315,6 +315,11 @@ func (b *EthAPIBackend) SubscribeChainHeadEvent(ch chan<- core.ChainHeadEvent) e
 	return b.eth.BlockChain().SubscribeChainHeadEvent(ch)
 }
 
+// SubscribeNewPayloadEvent registers a subscription for NewPayloadEvent.
+func (b *EthAPIBackend) SubscribeNewPayloadEvent(ch chan<- core.NewPayloadEvent) event.Subscription {
+	return b.eth.BlockChain().SubscribeNewPayloadEvent(ch)
+}
+
 func (b *EthAPIBackend) SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription {
 	return b.eth.BlockChain().SubscribeLogsEvent(ch)
 }

eth/catalyst/api.go

@@ -30,6 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/beacon/engine"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/rawdb"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth"
@@ -787,7 +788,9 @@ func (api *ConsensusAPI) newPayload(params engine.ExecutableData, versionedHashe
 		return engine.PayloadStatusV1{Status: engine.ACCEPTED}, nil
 	}
 	log.Trace("Inserting block without sethead", "hash", block.Hash(), "number", block.Number())
+	start := time.Now()
 	proofs, err := api.eth.BlockChain().InsertBlockWithoutSetHead(block, witness)
+	processingTime := time.Since(start)
 	if err != nil {
 		log.Warn("NewPayload: inserting block failed", "error", err)
 
@@ -800,6 +803,13 @@ func (api *ConsensusAPI) newPayload(params engine.ExecutableData, versionedHashe
 	}
 	hash := block.Hash()
 
+	// Emit NewPayloadEvent for ethstats reporting
+	api.eth.BlockChain().SendNewPayloadEvent(core.NewPayloadEvent{
+		Hash:           hash,
+		Number:         block.NumberU64(),
+		ProcessingTime: processingTime,
+	})
+
 	// If witness collection was requested, inject that into the result too
 	var ow *hexutil.Bytes
 	if proofs != nil {

ethstats/ethstats.go

@@ -63,6 +63,7 @@ const (
 type backend interface {
 	SubscribeChainHeadEvent(ch chan<- core.ChainHeadEvent) event.Subscription
 	SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription
+	SubscribeNewPayloadEvent(ch chan<- core.NewPayloadEvent) event.Subscription
 	CurrentHeader() *types.Header
 	HeaderByNumber(ctx context.Context, number rpc.BlockNumber) (*types.Header, error)
 	Stats() (pending int, queued int)
@@ -92,8 +93,9 @@ type Service struct {
 	pongCh chan struct{} // Pong notifications are fed into this channel
 	histCh chan []uint64 // History request block numbers are fed into this channel
 
-	headSub event.Subscription
-	txSub   event.Subscription
+	headSub       event.Subscription
+	txSub         event.Subscription
+	newPayloadSub event.Subscription
 }
 
 // connWrapper is a wrapper to prevent concurrent-write or concurrent-read on the
@@ -198,7 +200,9 @@ func (s *Service) Start() error {
 	s.headSub = s.backend.SubscribeChainHeadEvent(chainHeadCh)
 	txEventCh := make(chan core.NewTxsEvent, txChanSize)
 	s.txSub = s.backend.SubscribeNewTxsEvent(txEventCh)
-	go s.loop(chainHeadCh, txEventCh)
+	newPayloadCh := make(chan core.NewPayloadEvent, chainHeadChanSize)
+	s.newPayloadSub = s.backend.SubscribeNewPayloadEvent(newPayloadCh)
+	go s.loop(chainHeadCh, txEventCh, newPayloadCh)
 
 	log.Info("Stats daemon started")
 	return nil
@@ -208,18 +212,20 @@ func (s *Service) Start() error {
 func (s *Service) Stop() error {
 	s.headSub.Unsubscribe()
 	s.txSub.Unsubscribe()
+	s.newPayloadSub.Unsubscribe()
 	log.Info("Stats daemon stopped")
 	return nil
 }
 
 // loop keeps trying to connect to the netstats server, reporting chain events
 // until termination.
-func (s *Service) loop(chainHeadCh chan core.ChainHeadEvent, txEventCh chan core.NewTxsEvent) {
+func (s *Service) loop(chainHeadCh chan core.ChainHeadEvent, txEventCh chan core.NewTxsEvent, newPayloadCh chan core.NewPayloadEvent) {
 	// Start a goroutine that exhausts the subscriptions to avoid events piling up
 	var (
-		quitCh = make(chan struct{})
-		headCh = make(chan *types.Header, 1)
-		txCh   = make(chan struct{}, 1)
+		quitCh         = make(chan struct{})
+		headCh         = make(chan *types.Header, 1)
+		txCh           = make(chan struct{}, 1)
+		newPayloadEvCh = make(chan core.NewPayloadEvent, 1)
 	)
 	go func() {
 		var lastTx mclock.AbsTime
@@ -246,11 +252,20 @@ func (s *Service) loop(chainHeadCh chan core.ChainHeadEvent, txEventCh chan core
 				default:
 				}
 
+			// Notify of new payload events, but drop if too frequent
+			case ev := <-newPayloadCh:
+				select {
+				case newPayloadEvCh <- ev:
+				default:
+				}
+
 			// node stopped
 			case <-s.txSub.Err():
 				break HandleLoop
 			case <-s.headSub.Err():
 				break HandleLoop
+			case <-s.newPayloadSub.Err():
+				break HandleLoop
 			}
 		}
 		close(quitCh)
@@ -336,6 +351,10 @@ func (s *Service) loop(chainHeadCh chan core.ChainHeadEvent, txEventCh chan core
 					if err = s.reportPending(conn); err != nil {
 						log.Warn("Post-block transaction stats report failed", "err", err)
 					}
+				case ev := <-newPayloadEvCh:
+					if err = s.reportNewPayload(conn, ev); err != nil {
+						log.Warn("New payload stats report failed", "err", err)
+					}
 				case <-txCh:
 					if err = s.reportPending(conn); err != nil {
 						log.Warn("Transaction stats report failed", "err", err)
@@ -600,6 +619,33 @@ func (s uncleStats) MarshalJSON() ([]byte, error) {
 	return []byte("[]"), nil
 }
 
+// newPayloadStats is the information to report about new payload events.
+type newPayloadStats struct {
+	Number         uint64      `json:"number"`
+	Hash           common.Hash `json:"hash"`
+	ProcessingTime uint64      `json:"processingTime"` // nanoseconds
+}
+
+// reportNewPayload reports a new payload event to the stats server.
+func (s *Service) reportNewPayload(conn *connWrapper, ev core.NewPayloadEvent) error {
+	details := &newPayloadStats{
+		Number:         ev.Number,
+		Hash:           ev.Hash,
+		ProcessingTime: uint64(ev.ProcessingTime.Nanoseconds()),
+	}
+
+	log.Trace("Sending new payload to ethstats", "number", details.Number, "hash", details.Hash)
+
+	stats := map[string]interface{}{
+		"id":    s.node,
+		"block": details,
+	}
+	report := map[string][]interface{}{
+		"emit": {"block_new_payload", stats},
+	}
+	return conn.WriteJSON(report)
+}
+
 // reportBlock retrieves the current chain head and reports it to the stats server.
 func (s *Service) reportBlock(conn *connWrapper, header *types.Header) error {
 	// Gather the block details from the header or block chain