nimbus-eth2/beacon_chain/beacon_node.nim

1174 lines
43 KiB
Nim

import
# Standard library
os, net, tables, random, strutils, times, sequtils,
# Nimble packages
stew/[objects, bitseqs, byteutils],
chronos, chronicles, confutils, metrics,
json_serialization/std/[options, sets], serialization/errors,
kvstore, kvstore_lmdb, eth/async_utils,
# Local modules
spec/[datatypes, digest, crypto, beaconstate, helpers, validator, network],
conf, time, state_transition, beacon_chain_db,
validator_pool, extras, attestation_pool, block_pool, eth2_network,
beacon_node_types, mainchain_monitor, version, ssz, ssz/dynamic_navigator,
sync_protocol, request_manager, validator_keygen, interop, statusbar
const
genesisFile = "genesis.ssz"
hasPrompt = not defined(withoutPrompt)
maxEmptySlotCount = uint64(24*60*60) div SECONDS_PER_SLOT
# https://github.com/ethereum/eth2.0-metrics/blob/master/metrics.md#interop-metrics
declareGauge beacon_slot,
"Latest slot of the beacon chain state"
declareGauge beacon_head_slot,
"Slot of the head block of the beacon chain"
declareGauge beacon_head_root,
"Root of the head block of the beacon chain"
# Metrics for tracking attestation and beacon block loss
declareCounter beacon_attestations_sent,
"Number of beacon chain attestations sent by this peer"
declareCounter beacon_attestations_received,
"Number of beacon chain attestations received by this peer"
declareCounter beacon_blocks_proposed,
"Number of beacon chain blocks sent by this peer"
declareCounter beacon_blocks_received,
"Number of beacon chain blocks received by this peer"
logScope: topics = "beacnde"
type
BeaconNode = ref object
nickname: string
network: Eth2Node
forkVersion: array[4, byte]
networkIdentity: Eth2NodeIdentity
requestManager: RequestManager
bootstrapNodes: seq[BootstrapAddr]
db: BeaconChainDB
config: BeaconNodeConf
attachedValidators: ValidatorPool
blockPool: BlockPool
attestationPool: AttestationPool
mainchainMonitor: MainchainMonitor
beaconClock: BeaconClock
proc onBeaconBlock*(node: BeaconNode, blck: SignedBeaconBlock) {.gcsafe.}
proc updateHead(node: BeaconNode): BlockRef
proc saveValidatorKey(keyName, key: string, conf: BeaconNodeConf) =
let validatorsDir = conf.localValidatorsDir
let outputFile = validatorsDir / keyName
createDir validatorsDir
writeFile(outputFile, key)
info "Imported validator key", file = outputFile
proc getStateFromSnapshot(conf: BeaconNodeConf, state: var BeaconState): bool =
var
genesisPath = conf.dataDir/genesisFile
snapshotContents: TaintedString
writeGenesisFile = false
if conf.stateSnapshot.isSome:
let
snapshotPath = conf.stateSnapshot.get.string
snapshotExt = splitFile(snapshotPath).ext
if cmpIgnoreCase(snapshotExt, ".ssz") != 0:
error "The supplied state snapshot must be a SSZ file",
suppliedPath = snapshotPath
quit 1
snapshotContents = readFile(snapshotPath)
if fileExists(genesisPath):
let genesisContents = readFile(genesisPath)
if snapshotContents != genesisContents:
error "Data directory not empty. Existing genesis state differs from supplied snapshot",
dataDir = conf.dataDir.string, snapshot = snapshotPath
quit 1
else:
debug "No genesis file in data directory", genesisPath
writeGenesisFile = true
genesisPath = snapshotPath
else:
try:
snapshotContents = readFile(genesisPath)
except CatchableError as err:
error "Failed to read genesis file", err = err.msg
quit 1
try:
state = SSZ.decode(snapshotContents, BeaconState)
except SerializationError:
error "Failed to import genesis file", path = genesisPath
quit 1
info "Loaded genesis state", path = genesisPath
if writeGenesisFile:
try:
notice "Writing genesis to data directory", path = conf.dataDir/genesisFile
writeFile(conf.dataDir/genesisFile, snapshotContents.string)
except CatchableError as err:
error "Failed to persist genesis file to data dir",
err = err.msg, genesisFile = conf.dataDir/genesisFile
quit 1
result = true
proc addBootstrapAddr(v: var seq[BootstrapAddr], add: TaintedString) =
try:
v.add BootstrapAddr.initAddress(string add)
except CatchableError as e:
warn "Skipping invalid address", err = e.msg
proc loadBootstrapFile(bootstrapFile: string): seq[BootstrapAddr] =
if fileExists(bootstrapFile):
for line in lines(bootstrapFile):
result.addBootstrapAddr(line)
proc init*(T: type BeaconNode, conf: BeaconNodeConf): Future[BeaconNode] {.async.} =
let
networkId = getPersistentNetIdentity(conf)
nickname = if conf.nodeName == "auto": shortForm(networkId)
else: conf.nodeName
db = BeaconChainDB.init(kvStore LmdbStoreRef.init(conf.databaseDir))
var mainchainMonitor: MainchainMonitor
if not BlockPool.isInitialized(db):
# Fresh start - need to load a genesis state from somewhere
var genesisState = new BeaconState
# Try file from command line first
if not conf.getStateFromSnapshot(genesisState[]):
# Didn't work, try creating a genesis state using main chain monitor
# TODO Could move this to a separate "GenesisMonitor" process or task
# that would do only this - see
if conf.depositWeb3Url.len != 0:
mainchainMonitor = MainchainMonitor.init(
conf.depositWeb3Url, conf.depositContractAddress, Eth2Digest())
mainchainMonitor.start()
else:
error "No initial state, need genesis state or deposit contract address"
quit 1
genesisState[] = await mainchainMonitor.getGenesis()
if genesisState[].slot != GENESIS_SLOT:
# TODO how to get a block from a non-genesis state?
error "Starting from non-genesis state not supported",
stateSlot = genesisState[].slot,
stateRoot = hash_tree_root(genesisState[])
quit 1
let tailBlock = get_initial_beacon_block(genesisState[])
try:
BlockPool.preInit(db, genesisState[], tailBlock)
doAssert BlockPool.isInitialized(db), "preInit should have initialized db"
except CatchableError as e:
error "Failed to initialize database", err = e.msg
quit 1
# TODO check that genesis given on command line (if any) matches database
let
blockPool = BlockPool.init(db)
if mainchainMonitor.isNil and conf.depositWeb3Url.len != 0:
mainchainMonitor = MainchainMonitor.init(
conf.depositWeb3Url, conf.depositContractAddress,
blockPool.headState.data.data.eth1_data.block_hash)
mainchainMonitor.start()
var bootNodes: seq[BootstrapAddr]
for node in conf.bootstrapNodes: bootNodes.addBootstrapAddr(node)
bootNodes.add(loadBootstrapFile(string conf.bootstrapNodesFile))
bootNodes.add(loadBootstrapFile(conf.dataDir / "bootstrap_nodes.txt"))
bootNodes = filterIt(bootNodes, not it.isSameNode(networkId))
let
network = await createEth2Node(conf, bootNodes)
let addressFile = string(conf.dataDir) / "beacon_node.address"
network.saveConnectionAddressFile(addressFile)
var res = BeaconNode(
nickname: nickname,
network: network,
forkVersion: blockPool.headState.data.data.fork.current_version,
networkIdentity: networkId,
requestManager: RequestManager.init(network),
bootstrapNodes: bootNodes,
db: db,
config: conf,
attachedValidators: ValidatorPool.init(),
blockPool: blockPool,
attestationPool: AttestationPool.init(blockPool),
mainchainMonitor: mainchainMonitor,
beaconClock: BeaconClock.init(blockPool.headState.data.data),
)
# TODO sync is called when a remote peer is connected - is that the right
# time to do so?
let sync = network.protocolState(BeaconSync)
sync.init(blockPool, res.forkVersion,
proc(signedBlock: SignedBeaconBlock) =
if signedBlock.message.slot mod SLOTS_PER_EPOCH == 0:
# TODO this is a hack to make sure that lmd ghost is run regularly
# while syncing blocks - it's poor form to keep it here though -
# the logic should be moved elsewhere
# TODO why only when syncing? well, because the way the code is written
# we require a connection to a boot node to start, and that boot
# node will start syncing as part of connection setup - it looks
# like it needs to finish syncing before the slot timer starts
# ticking which is a problem: all the synced blocks will be added
# to the block pool without any periodic head updates while this
# process is ongoing (during a blank start for example), which
# leads to an unhealthy buildup of blocks in the non-finalized part
# of the block pool
# TODO is it a problem that someone sending us a block can force
# a potentially expensive head resolution?
discard res.updateHead()
onBeaconBlock(res, signedBlock))
return res
proc connectToNetwork(node: BeaconNode) {.async.} =
if node.bootstrapNodes.len > 0:
info "Connecting to bootstrap nodes", bootstrapNodes = node.bootstrapNodes
else:
info "Waiting for connections"
await node.network.connectToNetwork(node.bootstrapNodes)
template findIt(s: openarray, predicate: untyped): int =
var res = -1
for i, it {.inject.} in s:
if predicate:
res = i
break
res
proc addLocalValidator(
node: BeaconNode, state: BeaconState, privKey: ValidatorPrivKey) =
let pubKey = privKey.pubKey()
let idx = state.validators.findIt(it.pubKey == pubKey)
if idx == -1:
# We allow adding a validator even if its key is not in the state registry:
# it might be that the deposit for this validator has not yet been processed
warn "Validator not in registry (yet?)", pubKey
node.attachedValidators.addLocalValidator(pubKey, privKey)
proc addLocalValidators(node: BeaconNode, state: BeaconState) =
for validatorKey in node.config.validatorKeys:
node.addLocalValidator state, validatorKey
info "Local validators attached ", count = node.attachedValidators.count
func getAttachedValidator(node: BeaconNode,
state: BeaconState,
idx: ValidatorIndex): AttachedValidator =
let validatorKey = state.validators[idx].pubkey
node.attachedValidators.getValidator(validatorKey)
proc isSynced(node: BeaconNode, head: BlockRef): bool =
## TODO This function is here as a placeholder for some better heurestics to
## determine if we're in sync and should be producing blocks and
## attestations. Generally, the problem is that slot time keeps advancing
## even when there are no blocks being produced, so there's no way to
## distinguish validators geniunely going missing from the node not being
## well connected (during a network split or an internet outage for
## example). It would generally be correct to simply keep running as if
## we were the only legit node left alive, but then we run into issues:
## with enough many empty slots, the validator pool is emptied leading
## to empty committees and lots of empty slot processing that will be
## thrown away as soon as we're synced again.
let
# The slot we should be at, according to the clock
beaconTime = node.beaconClock.now()
wallSlot = beaconTime.toSlot()
# TODO if everyone follows this logic, the network will not recover from a
# halt: nobody will be producing blocks because everone expects someone
# else to do it
if wallSlot.afterGenesis and (wallSlot.slot > head.slot) and
(wallSlot.slot - head.slot) > maxEmptySlotCount:
false
else:
true
proc updateHead(node: BeaconNode): BlockRef =
# Check pending attestations - maybe we found some blocks for them
node.attestationPool.resolve()
# Grab the new head according to our latest attestation data
let newHead = node.attestationPool.selectHead()
# Store the new head in the block pool - this may cause epochs to be
# justified and finalized
node.blockPool.updateHead(newHead)
beacon_head_root.set newHead.root.toGaugeValue
newHead
proc sendAttestation(node: BeaconNode,
fork: Fork,
validator: AttachedValidator,
attestationData: AttestationData,
committeeLen: int,
indexInCommittee: int) {.async.} =
logScope: pcs = "send_attestation"
let
validatorSignature = await validator.signAttestation(attestationData, fork)
var aggregationBits = CommitteeValidatorsBits.init(committeeLen)
aggregationBits.setBit indexInCommittee
var attestation = Attestation(
data: attestationData,
signature: validatorSignature,
aggregation_bits: aggregationBits
)
node.network.broadcast(topicAttestations, attestation)
if node.config.dump:
SSZ.saveFile(
node.config.dumpDir / "att-" & $attestationData.slot & "-" &
$attestationData.index & "-" & validator.pubKey.shortLog &
".ssz", attestation)
info "Attestation sent",
attestationData = shortLog(attestationData),
validator = shortLog(validator),
signature = shortLog(validatorSignature),
indexInCommittee = indexInCommittee,
cat = "consensus"
beacon_attestations_sent.inc()
proc proposeBlock(node: BeaconNode,
validator: AttachedValidator,
head: BlockRef,
slot: Slot): Future[BlockRef] {.async.} =
logScope: pcs = "block_proposal"
if head.slot >= slot:
# We should normally not have a head newer than the slot we're proposing for
# but this can happen if block proposal is delayed
warn "Skipping proposal, have newer head already",
headSlot = shortLog(head.slot),
headBlockRoot = shortLog(head.root),
slot = shortLog(slot),
cat = "fastforward"
return head
# Advance state to the slot immediately preceding the one we're creating a
# block for - potentially we will be processing empty slots along the way.
let (nroot, nblck) = node.blockPool.withState(
node.blockPool.tmpState, head.atSlot(slot)):
let (eth1data, deposits) =
if node.mainchainMonitor.isNil:
(get_eth1data_stub(
state.eth1_deposit_index, slot.compute_epoch_at_slot()),
newSeq[Deposit]())
else:
(node.mainchainMonitor.eth1Data,
node.mainchainMonitor.getPendingDeposits())
# To create a block, we'll first apply a partial block to the state, skipping
# some validations.
let
fork = state.fork
blockBody = BeaconBlockBody(
randao_reveal: validator.genRandaoReveal(fork, slot),
eth1_data: eth1data,
attestations:
node.attestationPool.getAttestationsForBlock(state, slot),
deposits: deposits)
var
newBlock = SignedBeaconBlock(
message: BeaconBlock(
slot: slot,
parent_root: head.root,
body: blockBody))
tmpState = hashedState
discard state_transition(tmpState, newBlock.message, {skipValidation})
# TODO only enable in fast-fail debugging situations
# otherwise, bad attestations can bring down network
# doAssert ok # TODO: err, could this fail somehow?
newBlock.message.state_root = tmpState.root
let blockRoot = hash_tree_root(newBlock.message)
# Careful, state no longer valid after here..
# We use the fork from the pre-newBlock state which should be fine because
# fork carries two epochs, so even if it's a fork block, the right thing
# will happen here
newBlock.signature =
await validator.signBlockProposal(fork, slot, blockRoot)
(blockRoot, newBlock)
let newBlockRef = node.blockPool.add(nroot, nblck)
if newBlockRef == nil:
warn "Unable to add proposed block to block pool",
newBlock = shortLog(newBlock.message),
blockRoot = shortLog(blockRoot),
cat = "bug"
return head
info "Block proposed",
blck = shortLog(newBlock.message),
blockRoot = shortLog(newBlockRef.root),
validator = shortLog(validator),
cat = "consensus"
if node.config.dump:
SSZ.saveFile(
node.config.dumpDir / "block-" & $newBlock.message.slot & "-" &
shortLog(newBlockRef.root) & ".ssz", newBlock)
SSZ.saveFile(
node.config.dumpDir / "state-" & $tmpState.data.slot & "-" &
shortLog(newBlockRef.root) & "-" & shortLog(tmpState.root) & ".ssz",
tmpState.data)
node.network.broadcast(topicBeaconBlocks, newBlock)
beacon_blocks_proposed.inc()
return newBlockRef
proc onAttestation(node: BeaconNode, attestation: Attestation) =
# We received an attestation from the network but don't know much about it
# yet - in particular, we haven't verified that it belongs to particular chain
# we're on, or that it follows the rules of the protocol
logScope: pcs = "on_attestation"
debug "Attestation received",
attestationData = shortLog(attestation.data),
signature = shortLog(attestation.signature),
cat = "consensus" # Tag "consensus|attestation"?
let
wallSlot = node.beaconClock.now().toSlot()
head = node.blockPool.head
if not wallSlot.afterGenesis or wallSlot.slot < head.blck.slot:
warn "Received attestation before genesis or head - clock is wrong?",
afterGenesis = wallSlot.afterGenesis,
wallSlot = shortLog(wallSlot.slot),
headSlot = shortLog(head.blck.slot),
cat = "clock_drift" # Tag "attestation|clock_drift"?
return
if attestation.data.slot > head.blck.slot and
(attestation.data.slot - head.blck.slot) > maxEmptySlotCount:
warn "Ignoring attestation, head block too old (out of sync?)",
attestationSlot = attestation.data.slot, headSlot = head.blck.slot
return
node.attestationPool.add(attestation)
proc onBeaconBlock(node: BeaconNode, blck: SignedBeaconBlock) =
# We received a block but don't know much about it yet - in particular, we
# don't know if it's part of the chain we're currently building.
let blockRoot = hash_tree_root(blck.message)
debug "Block received",
blck = shortLog(blck.message),
blockRoot = shortLog(blockRoot),
cat = "block_listener",
pcs = "receive_block"
beacon_blocks_received.inc()
if node.blockPool.add(blockRoot, blck).isNil:
return
# The block we received contains attestations, and we might not yet know about
# all of them. Let's add them to the attestation pool - in case they block
# is not yet resolved, neither will the attestations be!
# But please note that we only care about recent attestations.
# TODO shouldn't add attestations if the block turns out to be invalid..
let currentSlot = node.beaconClock.now.toSlot
if currentSlot.afterGenesis and
blck.message.slot.epoch + 1 >= currentSlot.slot.epoch:
for attestation in blck.message.body.attestations:
node.onAttestation(attestation)
proc handleAttestations(node: BeaconNode, head: BlockRef, slot: Slot) =
## Perform all attestations that the validators attached to this node should
## perform during the given slot
logScope: pcs = "on_attestation"
if slot + SLOTS_PER_EPOCH < head.slot:
# The latest block we know about is a lot newer than the slot we're being
# asked to attest to - this makes it unlikely that it will be included
# at all.
# TODO the oldest attestations allowed are those that are older than the
# finalized epoch.. also, it seems that posting very old attestations
# is risky from a slashing perspective. More work is needed here.
notice "Skipping attestation, head is too recent",
headSlot = shortLog(head.slot),
slot = shortLog(slot)
return
let attestationHead = head.findAncestorBySlot(slot)
if head != attestationHead.blck:
# In rare cases, such as when we're busy syncing or just slow, we'll be
# attesting to a past state - we must then recreate the world as it looked
# like back then
notice "Attesting to a state in the past, falling behind?",
headSlot = shortLog(head.slot),
attestationHeadSlot = shortLog(attestationHead.slot),
attestationSlot = shortLog(slot)
trace "Checking attestations",
attestationHeadRoot = shortLog(attestationHead.blck.root),
attestationSlot = shortLog(slot),
cat = "attestation"
# Collect data to send before node.stateCache grows stale
var attestations: seq[tuple[
data: AttestationData, committeeLen, indexInCommittee: int,
validator: AttachedValidator]]
# We need to run attestations exactly for the slot that we're attesting to.
# In case blocks went missing, this means advancing past the latest block
# using empty slots as fillers.
# https://github.com/ethereum/eth2.0-specs/blob/v0.8.4/specs/validator/0_beacon-chain-validator.md#validator-assignments
# TODO we could cache the validator assignment since it's valid for the entire
# epoch since it doesn't change, but that has to be weighed against
# the complexity of handling forks correctly - instead, we use an adapted
# version here that calculates the committee for a single slot only
node.blockPool.withState(node.blockPool.tmpState, attestationHead):
var cache = get_empty_per_epoch_cache()
let committees_per_slot = get_committee_count_at_slot(state, slot)
for committee_index in 0'u64..<committees_per_slot:
let
committee = get_beacon_committee(state, slot, committee_index, cache)
for index_in_committee, validatorIdx in committee:
let validator = node.getAttachedValidator(state, validatorIdx)
if validator != nil:
let ad = makeAttestationData(state, slot, committee_index, blck.root)
attestations.add((ad, committee.len, index_in_committee, validator))
for a in attestations:
traceAsyncErrors sendAttestation(
node, state.fork, a.validator, a.data, a.committeeLen, a.indexInCommittee)
proc handleProposal(node: BeaconNode, head: BlockRef, slot: Slot):
Future[BlockRef] {.async.} =
## Perform the proposal for the given slot, iff we have a validator attached
## that is supposed to do so, given the shuffling in head
# TODO here we advance the state to the new slot, but later we'll be
# proposing for it - basically, we're selecting proposer based on an
# empty slot
var cache = get_empty_per_epoch_cache()
node.blockPool.withState(node.blockPool.tmpState, head.atSlot(slot)):
let proposerIdx = get_beacon_proposer_index(state, cache)
if proposerIdx.isNone:
notice "Missing proposer index",
slot=slot,
epoch=slot.compute_epoch_at_slot,
num_validators=state.validators.len,
active_validators=
get_active_validator_indices(state, slot.compute_epoch_at_slot),
balances=state.balances
return head
let validator = node.getAttachedValidator(state, proposerIdx.get)
if validator != nil:
return await proposeBlock(node, validator, head, slot)
trace "Expecting block proposal",
headRoot = shortLog(head.root),
slot = shortLog(slot),
proposer = shortLog(state.validators[proposerIdx.get].pubKey),
cat = "consensus",
pcs = "wait_for_proposal"
return head
proc onSlotStart(node: BeaconNode, lastSlot, scheduledSlot: Slot) {.gcsafe, async.} =
## Called at the beginning of a slot - usually every slot, but sometimes might
## skip a few in case we're running late.
## lastSlot: the last slot that we sucessfully processed, so we know where to
## start work from
## scheduledSlot: the slot that we were aiming for, in terms of timing
logScope: pcs = "slot_start"
let
# The slot we should be at, according to the clock
beaconTime = node.beaconClock.now()
wallSlot = beaconTime.toSlot()
info "Slot start",
lastSlot = shortLog(lastSlot),
scheduledSlot = shortLog(scheduledSlot),
beaconTime = shortLog(beaconTime),
peers = node.network.peersCount,
headSlot = shortLog(node.blockPool.head.blck.slot),
headEpoch = shortLog(node.blockPool.head.blck.slot.compute_epoch_at_slot()),
headRoot = shortLog(node.blockPool.head.blck.root),
finalizedSlot = shortLog(node.blockPool.finalizedHead.blck.slot),
finalizedRoot = shortLog(node.blockPool.finalizedHead.blck.root),
finalizedSlot = shortLog(node.blockPool.finalizedHead.blck.slot.compute_epoch_at_slot()),
cat = "scheduling"
if not wallSlot.afterGenesis or (wallSlot.slot < lastSlot):
let
slot =
if wallSlot.afterGenesis: wallSlot.slot
else: GENESIS_SLOT
nextSlot = slot + 1 # At least GENESIS_SLOT + 1!
# This can happen if the system clock changes time for example, and it's
# pretty bad
# TODO shut down? time either was or is bad, and PoS relies on accuracy..
warn "Beacon clock time moved back, rescheduling slot actions",
beaconTime = shortLog(beaconTime),
lastSlot = shortLog(lastSlot),
scheduledSlot = shortLog(scheduledSlot),
nextSlot = shortLog(nextSlot),
cat = "clock_drift" # tag "scheduling|clock_drift"?
addTimer(saturate(node.beaconClock.fromNow(nextSlot))) do (p: pointer):
asyncCheck node.onSlotStart(slot, nextSlot)
return
let
slot = wallSlot.slot # afterGenesis == true!
nextSlot = slot + 1
beacon_slot.set slot.int64
if slot > lastSlot + SLOTS_PER_EPOCH:
# We've fallen behind more than an epoch - there's nothing clever we can
# do here really, except skip all the work and try again later.
# TODO how long should the period be? Using an epoch because that's roughly
# how long attestations remain interesting
# TODO should we shut down instead? clearly we're unable to keep up
warn "Unable to keep up, skipping ahead",
lastSlot = shortLog(lastSlot),
slot = shortLog(slot),
nextSlot = shortLog(nextSlot),
scheduledSlot = shortLog(scheduledSlot),
cat = "overload"
addTimer(saturate(node.beaconClock.fromNow(nextSlot))) do (p: pointer):
# We pass the current slot here to indicate that work should be skipped!
asyncCheck node.onSlotStart(slot, nextSlot)
return
# Whatever we do during the slot, we need to know the head, because this will
# give us a state to work with and thus a shuffling.
# TODO typically, what consitutes correct actions stays constant between slot
# updates and is stable across some epoch transitions as well - see how
# we can avoid recalculating everything here
var head = node.updateHead()
# TODO is the slot of the clock or the head block more interestion? provide
# rationale in comment
beacon_head_slot.set slot.int64
# TODO if the head is very old, that is indicative of something being very
# wrong - us being out of sync or disconnected from the network - need
# to consider what to do in that case:
# * nothing - the other parts of the application will reconnect and
# start listening to broadcasts, learn a new head etc..
# risky, because the network might stall if everyone does
# this, because no blocks will be produced
# * shut down - this allows the user to notice and take action, but is
# kind of harsh
# * keep going - we create blocks and attestations as usual and send them
# out - if network conditions improve, fork choice should
# eventually select the correct head and the rest will
# disappear naturally - risky because user is not aware,
# and might lose stake on canonical chain but "just works"
# when reconnected..
if node.attachedValidators.count == 0:
# There are no validators, thus we don't have any additional work to do
# beyond keeping track of the head
discard
elif not node.isSynced(head):
warn "Node out of sync, skipping block and attestation production for this slot",
slot, headSlot = head.slot
else:
var curSlot = lastSlot + 1
while curSlot < slot:
# Timers may be delayed because we're busy processing, and we might have
# more work to do. We'll try to do so in an expedited way.
# TODO maybe even collect all work synchronously to avoid unnecessary
# state rewinds while waiting for async operations like validator
# signature..
notice "Catching up",
curSlot = shortLog(curSlot),
lastSlot = shortLog(lastSlot),
slot = shortLog(slot),
cat = "overload"
# For every slot we're catching up, we'll propose then send
# attestations - head should normally be advancing along the same branch
# in this case
# TODO what if we receive blocks / attestations while doing this work?
head = await handleProposal(node, head, curSlot)
# For each slot we missed, we need to send out attestations - if we were
# proposing during this time, we'll use the newly proposed head, else just
# keep reusing the same - the attestation that goes out will actually
# rewind the state to what it looked like at the time of that slot
# TODO smells like there's an optimization opportunity here
handleAttestations(node, head, curSlot)
curSlot += 1
head = await handleProposal(node, head, slot)
# We've been doing lots of work up until now which took time. Normally, we
# send out attestations at the slot mid-point, so we go back to the clock
# to see how much time we need to wait.
# TODO the beacon clock might jump here also. It's probably easier to complete
# the work for the whole slot using a monotonic clock instead, then deal
# with any clock discrepancies once only, at the start of slot timer
# processing..
# https://github.com/ethereum/eth2.0-specs/blob/v0.9.4/specs/validator/0_beacon-chain-validator.md#attesting
# A validator should create and broadcast the attestation to the
# associated attestation subnet one-third of the way through the slot
# during which the validator is assigned―that is, SECONDS_PER_SLOT / 3
# seconds after the start of slot.
let
attestationStart = node.beaconClock.fromNow(slot)
thirdSlot = seconds(int64(SECONDS_PER_SLOT)) div 3
if attestationStart.inFuture or attestationStart.offset <= thirdSlot:
let fromNow =
if attestationStart.inFuture: attestationStart.offset + thirdSlot
else: thirdSlot - attestationStart.offset
trace "Waiting to send attestations",
slot = shortLog(slot),
fromNow = shortLog(fromNow),
cat = "scheduling"
await sleepAsync(fromNow)
# Time passed - we might need to select a new head in that case
head = node.updateHead()
handleAttestations(node, head, slot)
# TODO ... and beacon clock might jump here also. sigh.
let
nextSlotStart = saturate(node.beaconClock.fromNow(nextSlot))
info "Slot end",
slot = shortLog(slot),
nextSlot = shortLog(nextSlot),
headSlot = shortLog(node.blockPool.head.blck.slot),
headEpoch = shortLog(node.blockPool.head.blck.slot.compute_epoch_at_slot()),
headRoot = shortLog(node.blockPool.head.blck.root),
finalizedSlot = shortLog(node.blockPool.finalizedHead.blck.slot),
finalizedEpoch = shortLog(node.blockPool.finalizedHead.blck.slot.compute_epoch_at_slot()),
finalizedRoot = shortLog(node.blockPool.finalizedHead.blck.root),
cat = "scheduling"
addTimer(nextSlotStart) do (p: pointer):
asyncCheck node.onSlotStart(slot, nextSlot)
proc handleMissingBlocks(node: BeaconNode) =
let missingBlocks = node.blockPool.checkMissing()
if missingBlocks.len > 0:
var left = missingBlocks.len
info "Requesting detected missing blocks", missingBlocks
node.requestManager.fetchAncestorBlocks(missingBlocks) do (b: SignedBeaconBlock):
onBeaconBlock(node, b)
# TODO instead of waiting for a full second to try the next missing block
# fetching, we'll do it here again in case we get all blocks we asked
# for (there might be new parents to fetch). of course, this is not
# good because the onSecond fetching also kicks in regardless but
# whatever - this is just a quick fix for making the testnet easier
# work with while the sync problem is dealt with more systematically
dec left
if left == 0:
addTimer(Moment.now()) do (p: pointer):
handleMissingBlocks(node)
proc onSecond(node: BeaconNode, moment: Moment) {.async.} =
node.handleMissingBlocks()
let nextSecond = max(Moment.now(), moment + chronos.seconds(1))
addTimer(nextSecond) do (p: pointer):
asyncCheck node.onSecond(nextSecond)
proc run*(node: BeaconNode) =
waitFor node.network.subscribe(topicBeaconBlocks) do (signedBlock: SignedBeaconBlock):
onBeaconBlock(node, signedBlock)
waitFor node.network.subscribe(topicAttestations) do (attestation: Attestation):
# Avoid double-counting attestation-topic attestations on shared codepath
# when they're reflected through beacon blocks
beacon_attestations_received.inc()
node.onAttestation(attestation)
let
t = node.beaconClock.now().toSlot()
curSlot = if t.afterGenesis: t.slot
else: GENESIS_SLOT
nextSlot = curSlot + 1 # No earlier than GENESIS_SLOT + 1
fromNow = saturate(node.beaconClock.fromNow(nextSlot))
info "Scheduling first slot action",
beaconTime = shortLog(node.beaconClock.now()),
nextSlot = shortLog(nextSlot),
fromNow = shortLog(fromNow),
cat = "scheduling"
addTimer(fromNow) do (p: pointer):
asyncCheck node.onSlotStart(curSlot, nextSlot)
let second = Moment.now() + chronos.seconds(1)
addTimer(second) do (p: pointer):
asyncCheck node.onSecond(second)
runForever()
var gPidFile: string
proc createPidFile(filename: string) =
createDir splitFile(filename).dir
writeFile filename, $os.getCurrentProcessId()
gPidFile = filename
addQuitProc proc {.noconv.} = removeFile gPidFile
proc start(node: BeaconNode) =
# TODO: while it's nice to cheat by waiting for connections here, we
# actually need to make this part of normal application flow -
# losing all connections might happen at any time and we should be
# prepared to handle it.
waitFor node.connectToNetwork()
let
head = node.blockPool.head
finalizedHead = node.blockPool.finalizedHead
info "Starting beacon node",
version = fullVersionStr,
timeSinceFinalization =
int64(finalizedHead.slot.toBeaconTime()) -
int64(node.beaconClock.now()),
headSlot = shortLog(head.blck.slot),
headRoot = shortLog(head.blck.root),
finalizedSlot = shortLog(finalizedHead.blck.slot),
finalizedRoot = shortLog(finalizedHead.blck.root),
SLOTS_PER_EPOCH,
SECONDS_PER_SLOT,
SPEC_VERSION,
dataDir = node.config.dataDir.string,
cat = "init",
pcs = "start_beacon_node"
let
bs = BlockSlot(blck: head.blck, slot: head.blck.slot)
node.blockPool.withState(node.blockPool.tmpState, bs):
node.addLocalValidators(state)
node.run()
func formatGwei(amount: uint64): string =
# TODO This is implemented in a quite a silly way.
# Better routines for formatting decimal numbers
# should exists somewhere else.
let
eth = amount div 1000000000
remainder = amount mod 1000000000
result = $eth
if remainder != 0:
result.add '.'
result.add $remainder
while result[^1] == '0':
result.setLen(result.len - 1)
when hasPrompt:
from unicode import Rune
import terminal, prompt
proc providePromptCompletions*(line: seq[Rune], cursorPos: int): seq[string] =
# TODO
# The completions should be generated with the general-purpose command-line
# parsing API of Confutils
result = @[]
proc processPromptCommands(p: ptr Prompt) {.thread.} =
while true:
var cmd = p[].readLine()
case cmd
of "quit":
quit 0
else:
p[].writeLine("Unknown command: " & cmd)
proc slotOrZero(time: BeaconTime): Slot =
let exSlot = time.toSlot
if exSlot.afterGenesis: exSlot.slot
else: Slot(0)
proc initPrompt(node: BeaconNode) =
if isatty(stdout) and node.config.statusBarEnabled:
enableTrueColors()
# TODO: nim-prompt seems to have threading issues at the moment
# which result in sporadic crashes. We should introduce a
# lock that guards the access to the internal prompt line
# variable.
#
# var p = Prompt.init("nimbus > ", providePromptCompletions)
# p.useHistoryFile()
proc dataResolver(expr: string): string =
# TODO:
# We should introduce a general API for resolving dot expressions
# such as `db.latest_block.slot` or `metrics.connected_peers`.
# Such an API can be shared between the RPC back-end, CLI tools
# such as ncli, a potential GraphQL back-end and so on.
# The status bar feature would allow the user to specify an
# arbitrary expression that is resolvable through this API.
case expr.toLowerAscii
of "connected_peers":
$(sync_protocol.libp2p_peers.value.int)
of "last_finalized_epoch":
var head = node.blockPool.finalizedHead
# TODO: Should we display a state root instead?
$(head.slot.epoch) & " (" & shortLog(head.blck.root) & ")"
of "epoch":
$node.beaconClock.now.slotOrZero.epoch
of "epoch_slot":
$(node.beaconClock.now.slotOrZero mod SLOTS_PER_EPOCH)
of "slots_per_epoch":
$SLOTS_PER_EPOCH
of "slot":
$node.beaconClock.now.slotOrZero
of "slot_trailing_digits":
var slotStr = $node.beaconClock.now.slotOrZero
if slotStr.len > 3: slotStr = slotStr[^3..^1]
slotStr
of "attached_validators_balance":
var balance = uint64(0)
# TODO slow linear scan!
for idx, b in node.blockPool.headState.data.data.balances:
if node.getAttachedValidator(
node.blockPool.headState.data.data, ValidatorIndex(idx)) != nil:
balance += b
formatGwei(balance)
else:
# We ignore typos for now and just render the expression
# as it was written. TODO: come up with a good way to show
# an error message to the user.
"$" & expr
var statusBar = StatusBarView.init(
node.config.statusBarContents,
dataResolver)
when compiles(defaultChroniclesStream.output.writer):
defaultChroniclesStream.output.writer =
proc (logLevel: LogLevel, msg: LogOutputStr) {.gcsafe.} =
# p.hidePrompt
erase statusBar
# p.writeLine msg
stdout.write msg
render statusBar
# p.showPrompt
proc statusBarUpdatesPollingLoop() {.async.} =
while true:
update statusBar
await sleepAsync(chronos.seconds(1))
traceAsyncErrors statusBarUpdatesPollingLoop()
# var t: Thread[ptr Prompt]
# createThread(t, processPromptCommands, addr p)
when isMainModule:
randomize()
let config = BeaconNodeConf.load(
version = clientId,
copyrightBanner = clientId & "\p" & copyrights)
when compiles(defaultChroniclesStream.output.writer):
defaultChroniclesStream.output.writer =
proc (logLevel: LogLevel, msg: LogOutputStr) {.gcsafe.} =
stdout.write(msg)
if config.logLevel != LogLevel.NONE:
setLogLevel(config.logLevel)
## Ctrl+C handling
proc controlCHandler() {.noconv.} =
when defined(windows):
# workaround for https://github.com/nim-lang/Nim/issues/4057
setupForeignThreadGc()
debug "Shutting down after having received SIGINT"
quit(QuitFailure)
setControlCHook(controlCHandler)
case config.cmd
of createTestnet:
var deposits: seq[Deposit]
for i in config.firstValidator.int ..< config.totalValidators.int:
let depositFile = config.validatorsDir /
validatorFileBaseName(i) & ".deposit.json"
try:
deposits.add Json.loadFile(depositFile, Deposit)
except SerializationError as err:
stderr.write "Error while loading a deposit file:\n"
stderr.write err.formatMsg(depositFile), "\n"
stderr.write "Please regenerate the deposit files by running makeDeposits again\n"
quit 1
let
startTime = uint64(times.toUnix(times.getTime()) + config.genesisOffset)
outGenesis = config.outputGenesis.string
eth1Hash = if config.depositWeb3Url.len == 0: eth1BlockHash
else: waitFor getLatestEth1BlockHash(config.depositWeb3Url)
var
initialState = initialize_beacon_state_from_eth1(
eth1Hash, startTime, deposits, {skipValidation})
# https://github.com/ethereum/eth2.0-pm/tree/6e41fcf383ebeb5125938850d8e9b4e9888389b4/interop/mocked_start#create-genesis-state
initialState.genesis_time = startTime
doAssert initialState.validators.len > 0
let outGenesisExt = splitFile(outGenesis).ext
if cmpIgnoreCase(outGenesisExt, ".json") == 0:
Json.saveFile(outGenesis, initialState, pretty = true)
echo "Wrote ", outGenesis
let outSszGenesis = outGenesis.changeFileExt "ssz"
SSZ.saveFile(outSszGenesis, initialState)
echo "Wrote ", outSszGenesis
var
bootstrapAddress = getPersistenBootstrapAddr(
config, parseIpAddress(config.bootstrapAddress), Port config.bootstrapPort)
let bootstrapFile = config.outputBootstrapFile.string
if bootstrapFile.len > 0:
let bootstrapAddrLine = $bootstrapAddress
writeFile(bootstrapFile, bootstrapAddrLine)
echo "Wrote ", bootstrapFile
of importValidator:
template reportFailureFor(keyExpr) =
error "Failed to import validator key", key = keyExpr
programResult = 1
if config.keyFiles.len == 0:
stderr.write "Please specify at least one keyfile to import."
quit 1
for keyFile in config.keyFiles:
try:
saveValidatorKey(keyFile.string.extractFilename,
readFile(keyFile.string), config)
except:
reportFailureFor keyFile.string
of noCommand:
createPidFile(config.dataDir.string / "beacon_node.pid")
var node = waitFor BeaconNode.init(config)
when hasPrompt:
initPrompt(node)
when useInsecureFeatures:
if config.metricsServer:
let metricsAddress = config.metricsServerAddress
info "Starting metrics HTTP server",
address = metricsAddress, port = config.metricsServerPort
metrics.startHttpServer(metricsAddress, Port(config.metricsServerPort))
if node.nickname != "":
dynamicLogScope(node = node.nickname): node.start()
else:
node.start()
of makeDeposits:
createDir(config.depositsDir)
let
quickstartDeposits = generateDeposits(
config.totalQuickstartDeposits, config.depositsDir, false)
randomDeposits = generateDeposits(
config.totalRandomDeposits, config.depositsDir, true,
firstIdx = config.totalQuickstartDeposits)
if config.depositWeb3Url.len > 0 and config.depositContractAddress.len > 0:
info "Sending deposits",
web3 = config.depositWeb3Url,
depositContract = config.depositContractAddress
waitFor sendDeposits(
quickstartDeposits & randomDeposits,
config.depositWeb3Url,
config.depositContractAddress,
config.depositPrivateKey)
of query:
case config.queryCmd
of QueryCmd.nimQuery:
# TODO: This will handle a simple subset of Nim using
# dot syntax and `[]` indexing.
echo "nim query: ", config.nimQueryExpression
of QueryCmd.get:
let pathFragments = config.getQueryPath.split('/', maxsplit = 1)
let bytes =
case pathFragments[0]
of "genesis_state":
readFile(config.dataDir/genesisFile).string.toBytes()
else:
stderr.write config.getQueryPath & " is not a valid path"
quit 1
let navigator = DynamicSszNavigator.init(bytes, BeaconState)
echo navigator.navigatePath(pathFragments[1 .. ^1]).toJson