# beacon_chain # Copyright (c) 2018-2024 Status Research & Development GmbH # Licensed and distributed under either of # * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT). # * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0). # at your option. This file may not be copied, modified, or distributed except according to those terms. {.push raises: [].} import stew/results, chronicles, chronos, metrics, ../spec/[forks, signatures, signatures_batch, eip7594_helpers], ../sszdump from std/deques import Deque, addLast, contains, initDeque, items, len, shrink from std/sequtils import mapIt from ../consensus_object_pools/consensus_manager import ConsensusManager, checkNextProposer, optimisticExecutionBlockHash, runProposalForkchoiceUpdated, shouldSyncOptimistically, updateHead, updateHeadWithExecution from ../consensus_object_pools/blockchain_dag import getBlockRef, getForkedBlock, getProposer, forkAtEpoch, loadExecutionBlockHash, markBlockVerified, validatorKey from ../beacon_clock import GetBeaconTimeFn, toFloatSeconds from ../consensus_object_pools/block_dag import BlockRef, root, shortLog, slot from ../consensus_object_pools/block_pools_types import EpochRef, VerifierError from ../consensus_object_pools/block_quarantine import addBlobless, addOrphan, addUnviable, pop, removeOrphan, addColumnless from ../consensus_object_pools/blob_quarantine import BlobQuarantine, hasBlobs, popBlobs, put from ../consensus_object_pools/data_column_quarantine import DataColumnQuarantine, hasDataColumns, popDataColumns, put from ../validators/validator_monitor import MsgSource, ValidatorMonitor, registerAttestationInBlock, registerBeaconBlock, registerSyncAggregateInBlock from ../networking/eth2_network import Eth2Node from ../beacon_chain_db import getBlobSidecar, putBlobSidecar, getDataColumnSidecar, putDataColumnSidecar from ../spec/state_transition_block import validate_blobs export sszdump, signatures_batch logScope: topics = "gossip_blocks" # Block Processor # ------------------------------------------------------------------------------ # The block processor moves blocks from "Incoming" to "Consensus verified" declareHistogram beacon_store_block_duration_seconds, "storeBlock() duration", buckets = [0.25, 0.5, 1, 2, 4, 8, Inf] const SLOTS_PER_PAYLOAD = SLOTS_PER_HISTORICAL_ROOT ## Number of slots we process between each execution payload execution, while ## syncing the finalized part of the chain PAYLOAD_PRE_WALL_SLOTS = SLOTS_PER_EPOCH * 2 ## Number of slots from wall time that we start processing every payload type BlockEntry = object blck*: ForkedSignedBeaconBlock blobs*: Opt[BlobSidecars] data_columns*: Opt[DataColumnSidecars] maybeFinalized*: bool ## The block source claims the block has been finalized already resfut*: Future[Result[void, VerifierError]].Raising([CancelledError]) queueTick*: Moment # Moment when block was enqueued validationDur*: Duration # Time it took to perform gossip validation src*: MsgSource BlockProcessor* = object ## This manages the processing of blocks from different sources ## Blocks and attestations are enqueued in a gossip-validated state ## ## from: ## - Gossip (when synced) ## - SyncManager (during sync) ## - RequestManager (missing ancestor blocks) ## ## are then consensus-verified and added to: ## - the blockchain DAG ## - database ## - attestation pool ## - fork choice ## ## The processor will also reinsert blocks from the quarantine, should a ## parent be found. # Config # ---------------------------------------------------------------- dumpEnabled: bool dumpDirInvalid: string dumpDirIncoming: string # Producers # ---------------------------------------------------------------- blockQueue: AsyncQueue[BlockEntry] # Consumer # ---------------------------------------------------------------- consensusManager: ref ConsensusManager ## Blockchain DAG, AttestationPool and Quarantine ## Blockchain DAG, AttestationPool, Quarantine, and ELManager validatorMonitor: ref ValidatorMonitor getBeaconTime: GetBeaconTimeFn blobQuarantine: ref BlobQuarantine dataColumnQuarantine: ref DataColumnQuarantine verifier: BatchVerifier lastPayload: Slot ## The slot at which we sent a payload to the execution client the last ## time NewPayloadStatus {.pure.} = enum valid notValid invalid noResponse ProcessingStatus {.pure.} = enum completed notCompleted # Initialization # ------------------------------------------------------------------------------ proc new*(T: type BlockProcessor, dumpEnabled: bool, dumpDirInvalid, dumpDirIncoming: string, rng: ref HmacDrbgContext, taskpool: TaskPoolPtr, consensusManager: ref ConsensusManager, validatorMonitor: ref ValidatorMonitor, blobQuarantine: ref BlobQuarantine, dataColumnQuarantine: ref DataColumnQuarantine, getBeaconTime: GetBeaconTimeFn): ref BlockProcessor = (ref BlockProcessor)( dumpEnabled: dumpEnabled, dumpDirInvalid: dumpDirInvalid, dumpDirIncoming: dumpDirIncoming, blockQueue: newAsyncQueue[BlockEntry](), consensusManager: consensusManager, validatorMonitor: validatorMonitor, blobQuarantine: blobQuarantine, dataColumnQuarantine: dataColumnQuarantine, getBeaconTime: getBeaconTime, verifier: BatchVerifier.init(rng, taskpool) ) # Sync callbacks # ------------------------------------------------------------------------------ func hasBlocks*(self: BlockProcessor): bool = self.blockQueue.len() > 0 # Storage # ------------------------------------------------------------------------------ proc dumpInvalidBlock*( self: BlockProcessor, signedBlock: ForkySignedBeaconBlock) = if self.dumpEnabled: dump(self.dumpDirInvalid, signedBlock) proc dumpBlock[T]( self: BlockProcessor, signedBlock: ForkySignedBeaconBlock, res: Result[T, VerifierError]) = if self.dumpEnabled and res.isErr: case res.error of VerifierError.Invalid: self.dumpInvalidBlock(signedBlock) of VerifierError.MissingParent: dump(self.dumpDirIncoming, signedBlock) else: discard from ../consensus_object_pools/block_clearance import addBackfillBlock, addHeadBlockWithParent, checkHeadBlock proc storeBackfillBlock( self: var BlockProcessor, signedBlock: ForkySignedBeaconBlock, blobsOpt: Opt[BlobSidecars], dataColumnsOpt: Opt[DataColumnSidecars]): Result[void, VerifierError] = # The block is certainly not missing any more self.consensusManager.quarantine[].missing.del(signedBlock.root) # Establish blob viability before calling addbackfillBlock to avoid # writing the block in case of blob error. # var blobsOk = true var columnsOk = true # var blobsOk = true # when typeof(signedBlock).kind >= ConsensusFork.Deneb: # if blobsOpt.isSome: # let blobs = blobsOpt.get() # let kzgCommits = signedBlock.message.body.blob_kzg_commitments.asSeq # if blobs.len > 0 or kzgCommits.len > 0: # let r = validate_blobs(kzgCommits, blobs.mapIt(KzgBlob(bytes: it.blob)), # blobs.mapIt(it.kzg_proof)) # if r.isErr(): # debug "backfill blob validation failed", # blockRoot = shortLog(signedBlock.root), # blobs = shortLog(blobs), # blck = shortLog(signedBlock.message), # kzgCommits = mapIt(kzgCommits, shortLog(it)), # signature = shortLog(signedBlock.signature), # msg = r.error() # blobsOk = r.isOk() # if not blobsOk: # return err(VerifierError.Invalid) when typeof(signedBlock).kind >= ConsensusFork.Deneb: if dataColumnsOpt.isSome: let data_columns = dataColumnsOpt.get() if data_columns.len > 0: for i in 0..= ConsensusFork.Bellatrix: receivedBlock.message.body.execution_payload.block_hash else: # https://github.com/nim-lang/Nim/issues/19802 (static(default(Eth2Digest))) # Only called when expecting this to be valid because `newPayload` or some # previous `forkchoiceUpdated` had already marked it as valid. However, if # it's not the block that was received, don't info/warn either way given a # relative lack of immediate evidence. if receivedExecutionBlockHash != headBlockHash: return case payloadExecutionStatus of PayloadExecutionStatus.valid: # situation nominal discard of PayloadExecutionStatus.accepted, PayloadExecutionStatus.syncing: info "execution payload forkChoiceUpdated status ACCEPTED/SYNCING, but was previously VALID", payloadExecutionStatus = $payloadExecutionStatus, headBlockHash, safeBlockHash, finalizedBlockHash, receivedBlock = shortLog(receivedBlock) of PayloadExecutionStatus.invalid, PayloadExecutionStatus.invalid_block_hash: warn "execution payload forkChoiceUpdated status INVALID, but was previously VALID", payloadExecutionStatus = $payloadExecutionStatus, headBlockHash, safeBlockHash, finalizedBlockHash, receivedBlock = shortLog(receivedBlock) from ../consensus_object_pools/attestation_pool import addForkChoice, selectOptimisticHead, BeaconHead from ../consensus_object_pools/spec_cache import get_attesting_indices from ../spec/datatypes/phase0 import TrustedSignedBeaconBlock from ../spec/datatypes/altair import SignedBeaconBlock from ../spec/datatypes/bellatrix import ExecutionPayload, SignedBeaconBlock from ../spec/datatypes/capella import ExecutionPayload, SignedBeaconBlock, asTrusted, shortLog # TODO investigate why this seems to allow compilation even though it doesn't # directly address deneb.ExecutionPayload when complaint was that it didn't # know about "deneb" from ../spec/datatypes/deneb import SignedBeaconBlock, asTrusted, shortLog proc newExecutionPayload*( elManager: ELManager, blck: SomeForkyBeaconBlock): Future[Opt[PayloadExecutionStatus]] {.async: (raises: [CancelledError]).} = template executionPayload: untyped = blck.body.execution_payload if not elManager.hasProperlyConfiguredConnection: if elManager.hasConnection: info "No execution client connected; cannot process block payloads", executionPayload = shortLog(executionPayload) else: debug "No execution client connected; cannot process block payloads", executionPayload = shortLog(executionPayload) return Opt.none PayloadExecutionStatus debug "newPayload: inserting block into execution engine", executionPayload = shortLog(executionPayload) try: let payloadStatus = await elManager.sendNewPayload(blck) debug "newPayload: succeeded", parentHash = executionPayload.parent_hash, blockHash = executionPayload.block_hash, blockNumber = executionPayload.block_number, payloadStatus = $payloadStatus return Opt.some payloadStatus except CatchableError as err: warn "newPayload failed - check execution client", msg = err.msg, parentHash = shortLog(executionPayload.parent_hash), blockHash = shortLog(executionPayload.block_hash), blockNumber = executionPayload.block_number return Opt.none PayloadExecutionStatus proc getExecutionValidity( elManager: ELManager, blck: bellatrix.SignedBeaconBlock | capella.SignedBeaconBlock | deneb.SignedBeaconBlock | electra.SignedBeaconBlock): Future[NewPayloadStatus] {.async: (raises: [CancelledError]).} = if not blck.message.is_execution_block: return NewPayloadStatus.valid # vacuously try: let executionPayloadStatus = await elManager.newExecutionPayload( blck.message) if executionPayloadStatus.isNone: return NewPayloadStatus.noResponse case executionPayloadStatus.get of PayloadExecutionStatus.invalid, PayloadExecutionStatus.invalid_block_hash: # Blocks come either from gossip or request manager requests. In the # former case, they've passed libp2p gosisp validation which implies # correct signature for correct proposer,which makes spam expensive, # while for the latter, spam is limited by the request manager. info "execution payload invalid from EL client newPayload", executionPayloadStatus = $executionPayloadStatus.get, executionPayload = shortLog(blck.message.body.execution_payload), blck = shortLog(blck) return NewPayloadStatus.invalid of PayloadExecutionStatus.syncing, PayloadExecutionStatus.accepted: return NewPayloadStatus.notValid of PayloadExecutionStatus.valid: return NewPayloadStatus.valid except CatchableError as err: error "newPayload failed and leaked exception", err = err.msg, executionPayload = shortLog(blck.message.body.execution_payload), blck = shortLog(blck) return NewPayloadStatus.noResponse proc checkBloblessSignature( self: BlockProcessor, signed_beacon_block: deneb.SignedBeaconBlock | electra.SignedBeaconBlock): Result[void, cstring] = let dag = self.consensusManager.dag let parent = dag.getBlockRef(signed_beacon_block.message.parent_root).valueOr: return err("checkBloblessSignature called with orphan block") let proposer = getProposer( dag, parent, signed_beacon_block.message.slot).valueOr: return err("checkBloblessSignature: Cannot compute proposer") if distinctBase(proposer) != signed_beacon_block.message.proposer_index: return err("checkBloblessSignature: Incorrect proposer") if not verify_block_signature( dag.forkAtEpoch(signed_beacon_block.message.slot.epoch), getStateField(dag.headState, genesis_validators_root), signed_beacon_block.message.slot, signed_beacon_block.root, dag.validatorKey(proposer).get(), signed_beacon_block.signature): return err("checkBloblessSignature: Invalid proposer signature") ok() proc enqueueBlock*( self: var BlockProcessor, src: MsgSource, blck: ForkedSignedBeaconBlock, blobs: Opt[BlobSidecars], data_columns: Opt[DataColumnSidecars], resfut: Future[Result[void, VerifierError]].Raising([CancelledError]) = nil, maybeFinalized = false, validationDur = Duration()) = withBlck(blck): if forkyBlck.message.slot <= self.consensusManager.dag.finalizedHead.slot: # let backfill blocks skip the queue - these are always "fast" to process # because there are no state rewinds to deal with let res = self.storeBackfillBlock(forkyBlck, blobs, data_columns) resfut.complete(res) return try: self.blockQueue.addLastNoWait(BlockEntry( blck: blck, blobs: Opt.none(BlobSidecars), data_columns: data_columns, maybeFinalized: maybeFinalized, resfut: resfut, queueTick: Moment.now(), validationDur: validationDur, src: src)) except AsyncQueueFullError: raiseAssert "unbounded queue" proc storeBlock( self: ref BlockProcessor, src: MsgSource, wallTime: BeaconTime, signedBlock: ForkySignedBeaconBlock, blobsOpt: Opt[BlobSidecars], dataColumnsOpt: Opt[DataColumnSidecars], maybeFinalized = false, queueTick: Moment = Moment.now(), validationDur = Duration()): Future[Result[BlockRef, (VerifierError, ProcessingStatus)]] {.async: (raises: [CancelledError]).} = ## storeBlock is the main entry point for unvalidated blocks - all untrusted ## blocks, regardless of origin, pass through here. When storing a block, ## we will add it to the dag and pass it to all block consumers that need ## to know about it, such as the fork choice and the monitoring let attestationPool = self.consensusManager.attestationPool startTick = Moment.now() vm = self.validatorMonitor dag = self.consensusManager.dag wallSlot = wallTime.slotOrZero # If the block is missing its parent, it will be re-orphaned below self.consensusManager.quarantine[].removeOrphan(signedBlock) # The block is certainly not missing any more self.consensusManager.quarantine[].missing.del(signedBlock.root) if signedBlock.message.parent_root in self.consensusManager.quarantine[].unviable: # DAG doesn't know about unviable ancestor blocks - we do however! self.consensusManager.quarantine[].addUnviable(signedBlock.root) return err((VerifierError.UnviableFork, ProcessingStatus.completed)) template handleVerifierError(errorParam: VerifierError): auto = let error = errorParam case error of VerifierError.MissingParent: if (let r = self.consensusManager.quarantine[].addOrphan( dag.finalizedHead.slot, ForkedSignedBeaconBlock.init(signedBlock)); r.isErr()): debug "could not add orphan", blockRoot = shortLog(signedBlock.root), blck = shortLog(signedBlock.message), signature = shortLog(signedBlock.signature), err = r.error() else: # if blobsOpt.isSome: # for blobSidecar in blobsOpt.get: # self.blobQuarantine[].put(blobSidecar) # debug "Block quarantined", # blockRoot = shortLog(signedBlock.root), # blck = shortLog(signedBlock.message), # signature = shortLog(signedBlock.signature) if dataColumnsOpt.isSome: for dataColumnSidecar in dataColumnsOpt.get: self.dataColumnQuarantine[].put(dataColumnSidecar) debug "Block quarantined", blockRoot = shortLog(signedBlock.root), blck = shortLog(signedBlock.message), signature = shortLog(signedBlock.signature) of VerifierError.UnviableFork: # Track unviables so that descendants can be discarded promptly self.consensusManager.quarantine[].addUnviable(signedBlock.root) else: discard err((error, ProcessingStatus.completed)) let # We have to be careful that there exists only one in-flight entry point # for adding blocks or the checks performed in `checkHeadBlock` might # be invalidated (ie a block could be added while we wait for EL response # here) parent = dag.checkHeadBlock(signedBlock) if parent.isErr(): # TODO This logic can be removed if the database schema is extended # to store non-canonical heads on top of the canonical head! # If that is done, the database no longer contains extra blocks # that have not yet been assigned a `BlockRef` if parent.error() == VerifierError.MissingParent: # This indicates that no `BlockRef` is available for the `parent_root`. # However, the block may still be available in local storage. On startup, # only the canonical branch is imported into `blockchain_dag`, while # non-canonical branches are re-discovered with sync/request managers. # Data from non-canonical branches that has already been verified during # a previous run of the beacon node is already stored in the database but # only lacks a `BlockRef`. Loading the branch from the database saves a # lot of time, especially when a non-canonical branch has non-trivial # depth. Note that if it turns out that a non-canonical branch eventually # becomes canonical, it is vital to import it as quickly as possible. let parent_root = signedBlock.message.parent_root parentBlck = dag.getForkedBlock(parent_root) if parentBlck.isSome(): var blobsOk = true let blobs = withBlck(parentBlck.get()): when consensusFork >= ConsensusFork.Deneb: var blob_sidecars: BlobSidecars for i in 0 ..< forkyBlck.message.body.blob_kzg_commitments.len: let blob = BlobSidecar.new() if not dag.db.getBlobSidecar(parent_root, i.BlobIndex, blob[]): blobsOk = false # Pruned, or inconsistent DB break blob_sidecars.add blob Opt.some blob_sidecars else: Opt.none BlobSidecars if blobsOk: debug "Loaded parent block from storage", parent_root self[].enqueueBlock( MsgSource.gossip, parentBlck.unsafeGet().asSigned(), blobs, Opt.none(DataColumnSidecars)) var columnsOk = true let data_columns = withBlck(parentBlck.get()): when consensusFork >= ConsensusFork.Deneb: var data_column_sidecars: DataColumnSidecars for i in 0.. signedBlock.message.slot and (signedBlock.message.slot + PAYLOAD_PRE_WALL_SLOTS) < wallSlot and signedBlock.message.is_execution_block: # Skip payload validation when message source (reasonably) claims block # has been finalized - this speeds up forward sync - in the worst case # that the claim is false, we will correct every time we process a block # from an honest source (or when we're close to head). # Occasionally we also send a payload to the EL so that it can # progress in its own sync. NewPayloadStatus.noResponse else: when typeof(signedBlock).kind >= ConsensusFork.Bellatrix: await self.consensusManager.elManager.getExecutionValidity(signedBlock) else: NewPayloadStatus.valid # vacuously payloadValid = payloadStatus == NewPayloadStatus.valid if NewPayloadStatus.invalid == payloadStatus: self.consensusManager.quarantine[].addUnviable(signedBlock.root) self[].dumpInvalidBlock(signedBlock) return err((VerifierError.UnviableFork, ProcessingStatus.completed)) if NewPayloadStatus.noResponse == payloadStatus: # When the execution layer is not available to verify the payload, we do the # required check on the CL side instead and proceed as if the EL was syncing # TODO run https://github.com/ethereum/consensus-specs/blob/v1.3.0/specs/deneb/beacon-chain.md#blob-kzg-commitments # https://github.com/ethereum/execution-apis/blob/main/src/engine/experimental/blob-extension.md#specification # "This validation MUST be instantly run in all cases even during active sync process." # # Client software MUST validate `blockHash` value as being equivalent to # `Keccak256(RLP(ExecutionBlockHeader))` # https://github.com/ethereum/execution-apis/blob/v1.0.0-beta.3/src/engine/paris.md#specification when typeof(signedBlock).kind >= ConsensusFork.Bellatrix and typeof(signedBlock).kind <= ConsensusFork.Deneb: debugComment "electra can do this in principle" template payload(): auto = signedBlock.message.body.execution_payload if signedBlock.message.is_execution_block and payload.block_hash != signedBlock.message.compute_execution_block_hash(): debug "Execution block hash validation failed", execution_payload = shortLog(payload) self[].dumpInvalidBlock(signedBlock) doAssert strictVerification notin dag.updateFlags self.consensusManager.quarantine[].addUnviable(signedBlock.root) return err((VerifierError.Invalid, ProcessingStatus.completed)) else: discard let newPayloadTick = Moment.now() # TODO with v1.4.0, not sure this is still relevant # Establish blob viability before calling addHeadBlock to avoid # writing the block in case of blob error. # when typeof(signedBlock).kind >= ConsensusFork.Deneb: # if blobsOpt.isSome: # let blobs = blobsOpt.get() # let kzgCommits = signedBlock.message.body.blob_kzg_commitments.asSeq # if blobs.len > 0 or kzgCommits.len > 0: # let r = validate_blobs(kzgCommits, blobs.mapIt(KzgBlob(bytes: it.blob)), # blobs.mapIt(it.kzg_proof)) # if r.isErr(): # debug "blob validation failed", # blockRoot = shortLog(signedBlock.root), # blobs = shortLog(blobs), # blck = shortLog(signedBlock.message), # kzgCommits = mapIt(kzgCommits, shortLog(it)), # signature = shortLog(signedBlock.signature), # msg = r.error() # return err((VerifierError.Invalid, ProcessingStatus.completed)) # if dataColumnsOpt.isSome: # let data_column_sidecars = dataColumnsOpt.get # if data_column_sidecars.len > 0: # for i in 0..= ConsensusFork.Altair and Trusted isnot phase0.TrustedSignedBeaconBlock: # altair+ for i in trustedBlock.message.body.sync_aggregate.sync_committee_bits.oneIndices(): vm[].registerSyncAggregateInBlock( trustedBlock.message.slot, trustedBlock.root, forkyState.data.current_sync_committee.pubkeys.data[i]) self[].dumpBlock(signedBlock, blck) # There can be a scenario where we receive a block we already received. # However this block was before the last finalized epoch and so its parent # was pruned from the ForkChoice. if blck.isErr(): return handleVerifierError(blck.error()) # Even if the EL is not responding, we'll only try once every now and then # to give it a block - this avoids a pathological slowdown where a busy EL # times out on every block we give it because it's busy with the previous # one self[].lastPayload = signedBlock.message.slot # write blobs now that block has been written. let blobs = blobsOpt.valueOr: BlobSidecars @[] for b in blobs: self.consensusManager.dag.db.putBlobSidecar(b[]) # write data columns now that block has been written. let data_columns = dataColumnsOpt.valueOr: DataColumnSidecars @[] for c in data_columns: self.consensusManager.dag.db.putDataColumnSidecar(c[]) debug "Data column written to database!" let addHeadBlockTick = Moment.now() # Eagerly update head: the incoming block "should" get selected. # # storeBlock gets called from validator_duties, which depends on its not # blocking progress any longer than necessary, and processBlock here, in # which case it's fine to await for a while on engine API results. # # Three general scenarios: (1) pre-merge; (2) merge, already `VALID` by way # of `newPayload`; (3) optimistically imported, need to call fcU before DAG # updateHead. Because in a non-finalizing network, completing sync isn't as # useful because regular reorgs likely still occur, and when finalizing the # EL is only called every SLOTS_PER_PAYLOAD slots regardless, await, rather # than asyncSpawn forkchoiceUpdated calls. # # This reduces in-flight fcU spam, which both reduces EL load and decreases # otherwise somewhat unpredictable CL head movement. # Grab the new head according to our latest attestation data; determines how # async this needs to be. let newHead = attestationPool[].selectOptimisticHead( wallSlot.start_beacon_time) if newHead.isOk: template elManager(): auto = self.consensusManager.elManager if self.consensusManager[].shouldSyncOptimistically(wallSlot): # Optimistic head is far in the future; report it as head block to EL. # Note that the specification allows an EL client to skip fcU processing # if an update to an ancestor is requested. # > Client software MAY skip an update of the forkchoice state and MUST # NOT begin a payload build process if `forkchoiceState.headBlockHash` # references an ancestor of the head of canonical chain. # https://github.com/ethereum/execution-apis/blob/v1.0.0-beta.3/src/engine/paris.md#specification-1 # # However, in practice, an EL client may not have completed importing all # block headers, so may be unaware of a block's ancestor status. # Therefore, hopping back and forth between the optimistic head and the # chain DAG head does not work well in practice, e.g., Geth: # - "Beacon chain gapped" from DAG head to optimistic head, # - followed by "Beacon chain reorged" from optimistic head back to DAG. self.consensusManager[].updateHead(newHead.get.blck) template callForkchoiceUpdated(attributes: untyped) = if NewPayloadStatus.noResponse != payloadStatus and not self.consensusManager[].optimisticExecutionBlockHash.isZero: discard await elManager.forkchoiceUpdated( headBlockHash = self.consensusManager[].optimisticExecutionBlockHash, safeBlockHash = newHead.get.safeExecutionBlockHash, finalizedBlockHash = newHead.get.finalizedExecutionBlockHash, payloadAttributes = none attributes) let consensusFork = self.consensusManager.dag.cfg.consensusForkAtEpoch( newHead.get.blck.bid.slot.epoch) withConsensusFork(consensusFork): when consensusFork >= ConsensusFork.Bellatrix: callForkchoiceUpdated(consensusFork.PayloadAttributes) else: let headExecutionBlockHash = dag.loadExecutionBlockHash(newHead.get.blck).get(ZERO_HASH) wallSlot = self.getBeaconTime().slotOrZero if headExecutionBlockHash.isZero or NewPayloadStatus.noResponse == payloadStatus: # Blocks without execution payloads can't be optimistic, and don't try # to fcU to a block the EL hasn't seen self.consensusManager[].updateHead(newHead.get.blck) elif newHead.get.blck.executionValid: # `forkchoiceUpdated` necessary for EL client only. self.consensusManager[].updateHead(newHead.get.blck) template callExpectValidFCU(payloadAttributeType: untyped): auto = await elManager.expectValidForkchoiceUpdated( headBlockPayloadAttributesType = payloadAttributeType, headBlockHash = headExecutionBlockHash, safeBlockHash = newHead.get.safeExecutionBlockHash, finalizedBlockHash = newHead.get.finalizedExecutionBlockHash, receivedBlock = signedBlock) template callForkChoiceUpdated: auto = case self.consensusManager.dag.cfg.consensusForkAtEpoch( newHead.get.blck.bid.slot.epoch) of ConsensusFork.Deneb, ConsensusFork.Electra: # https://github.com/ethereum/execution-apis/blob/90a46e9137c89d58e818e62fa33a0347bba50085/src/engine/prague.md # does not define any new forkchoiceUpdated, so reuse V3 from Dencun callExpectValidFCU(payloadAttributeType = PayloadAttributesV3) of ConsensusFork.Capella: callExpectValidFCU(payloadAttributeType = PayloadAttributesV2) of ConsensusFork.Phase0, ConsensusFork.Altair, ConsensusFork.Bellatrix: callExpectValidFCU(payloadAttributeType = PayloadAttributesV1) if self.consensusManager.checkNextProposer(wallSlot).isNone: # No attached validator is next proposer, so use non-proposal fcU callForkChoiceUpdated() else: # Some attached validator is next proposer, so prepare payload. As # updateHead() updated the DAG head, runProposalForkchoiceUpdated, # which needs the state corresponding to that head block, can run. if (await self.consensusManager.runProposalForkchoiceUpdated( wallSlot)).isNone: callForkChoiceUpdated() else: await self.consensusManager.updateHeadWithExecution( newHead.get, self.getBeaconTime) else: warn "Head selection failed, using previous head", head = shortLog(dag.head), wallSlot let updateHeadTick = Moment.now() queueDur = startTick - queueTick newPayloadDur = newPayloadTick - startTick addHeadBlockDur = addHeadBlockTick - newPayloadTick updateHeadDur = updateHeadTick - addHeadBlockTick # "store block" is the full time it takes to process the block - in the log # we split this into execution and consensus timings storeBlockDur = newPayloadDur + addHeadBlockDur beacon_store_block_duration_seconds.observe(storeBlockDur.toFloatSeconds()) debug "Block processed", head = shortLog(dag.head), blck = shortLog(blck.get()), validationDur, queueDur, newPayloadDur, addHeadBlockDur, updateHeadDur for quarantined in self.consensusManager.quarantine[].pop(blck.get().root): # Process the blocks that had the newly accepted block as parent debug "Block from quarantine", blockRoot = shortLog(signedBlock.root), quarantined = shortLog(quarantined.root) withBlck(quarantined): when typeof(forkyBlck).kind < ConsensusFork.Deneb: self[].enqueueBlock( MsgSource.gossip, quarantined, Opt.none(BlobSidecars), Opt.none(DataColumnSidecars)) else: if len(forkyBlck.message.body.blob_kzg_commitments) == 0: self[].enqueueBlock( MsgSource.gossip, quarantined, Opt.some(BlobSidecars @[]), Opt.some(DataColumnSidecars @[])) else: if (let res = checkBloblessSignature(self[], forkyBlck); res.isErr): warn "Failed to verify signature of unorphaned blobless/columnless block", blck = shortLog(forkyBlck), error = res.error() continue if self.blobQuarantine[].hasBlobs(forkyBlck): let blobs = self.blobQuarantine[].popBlobs( forkyBlck.root, forkyBlck) self[].enqueueBlock(MsgSource.gossip, quarantined, Opt.some(blobs), Opt.none(DataColumnSidecars)) else: discard self.consensusManager.quarantine[].addBlobless( dag.finalizedHead.slot, forkyBlck) if self.dataColumnQuarantine[].hasDataColumns(forkyBlck): let data_columns = self.dataColumnQuarantine[].popDataColumns( forkyBlck.root, forkyBlck) self[].enqueueBlock(MsgSource.gossip, quarantined, Opt.none(BlobSidecars), Opt.some(data_columns)) else: discard self.consensusManager.quarantine[].addColumnless( dag.finalizedHead.slot, forkyBlck) ok blck.value() # Enqueue # ------------------------------------------------------------------------------ proc addBlock*( self: var BlockProcessor, src: MsgSource, blck: ForkedSignedBeaconBlock, blobs: Opt[BlobSidecars], data_columns: Opt[DataColumnSidecars], maybeFinalized = false, validationDur = Duration()): Future[Result[void, VerifierError]] {.async: (raises: [CancelledError], raw: true).} = ## Enqueue a Gossip-validated block for consensus verification # Backpressure: # There is no backpressure here - producers must wait for `resfut` to # constrain their own processing # Producers: # - Gossip (when synced) # - SyncManager (during sync) # - RequestManager (missing ancestor blocks) # - API let resfut = newFuture[Result[void, VerifierError]]("BlockProcessor.addBlock") enqueueBlock(self, src, blck, blobs, data_columns, resfut, maybeFinalized, validationDur) resfut # Event Loop # ------------------------------------------------------------------------------ proc processBlock( self: ref BlockProcessor, entry: BlockEntry) {.async: (raises: [CancelledError]).} = logScope: blockRoot = shortLog(entry.blck.root) let wallTime = self.getBeaconTime() (afterGenesis, _) = wallTime.toSlot() if not afterGenesis: error "Processing block before genesis, clock turned back?" quit 1 let res = withBlck(entry.blck): await self.storeBlock( entry.src, wallTime, forkyBlck, entry.blobs, entry.data_columns, entry.maybeFinalized, entry.queueTick, entry.validationDur) if res.isErr and res.error[1] == ProcessingStatus.notCompleted: # When an execution engine returns an error or fails to respond to a # payload validity request for some block, a consensus engine: # - MUST NOT optimistically import the block. # - MUST NOT apply the block to the fork choice store. # - MAY queue the block for later processing. # https://github.com/ethereum/consensus-specs/blob/v1.5.0-alpha.2/sync/optimistic.md#execution-engine-errors await sleepAsync(chronos.seconds(1)) self[].enqueueBlock( entry.src, entry.blck, entry.blobs, entry.data_columns, entry.resfut, entry.maybeFinalized, entry.validationDur) # To ensure backpressure on the sync manager, do not complete these futures. return if entry.resfut != nil: entry.resfut.complete( if res.isOk(): Result[void, VerifierError].ok() else: Result[void, VerifierError].err(res.error()[0])) proc runQueueProcessingLoop*(self: ref BlockProcessor) {.async.} = while true: # Cooperative concurrency: one block per loop iteration - because # we run both networking and CPU-heavy things like block processing # on the same thread, we need to make sure that there is steady progress # on the networking side or we get long lockups that lead to timeouts. const # We cap waiting for an idle slot in case there's a lot of network traffic # taking up all CPU - we don't want to _completely_ stop processing blocks # in this case - doing so also allows us to benefit from more batching / # larger network reads when under load. idleTimeout = 10.milliseconds discard await idleAsync().withTimeout(idleTimeout) await self.processBlock(await self[].blockQueue.popFirst())