nimbus-eth2/research/block_sim.nim
Jacek Sieka 03005f48e1
Backfill support for ChainDAG (#3171)
In the ChainDAG, 3 block pointers are kept: genesis, tail and head. This
PR adds one more block pointer: the backfill block which represents the
block that has been backfilled so far.

When doing a checkpoint sync, a random block is given as starting point
- this is the tail block, and we require that the tail block has a
corresponding state.

When backfilling, we end up with blocks without corresponding states,
hence we cannot use `tail` as a backfill pointer - there is no state.

Nonetheless, we need to keep track of where we are in the backfill
process between restarts, such that we can answer GetBeaconBlocksByRange
requests.

This PR adds the basic support for backfill handling - it needs to be
integrated with backfill sync, and the REST API needs to be adjusted to
take advantage of the new backfilled blocks when responding to certain
requests.

Future work will also enable moving the tail in either direction:
* pruning means moving the tail forward in time and removing states
* backwards means recreating past states from genesis, such that
intermediate states are recreated step by step all the way to the tail -
at that point, tail, genesis and backfill will match up.
* backfilling is done when backfill != genesis - later, this will be the
WSS checkpoint instead
2021-12-13 14:36:06 +01:00

432 lines
15 KiB
Nim

# beacon_chain
# Copyright (c) 2019-2021 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.
# `block_sim` is a block and attestation simulator similar to `state_sim` whose
# task is to run the beacon chain without considering the network or the
# wall clock. Functionally, it achieves the same as the distributed beacon chain
# by producing blocks and attestations as if they were created by separate
# nodes, just like a set of `beacon_node` instances would.
#
# Similar to `state_sim`, but uses the block and attestation pools along with
# a database, as if a real node was running.
import
math, stats, times, strformat,
tables, options, random, tables, os,
confutils, chronicles, eth/db/kvstore_sqlite3,
chronos/timer, eth/keys, taskpools,
../tests/testblockutil,
../beacon_chain/spec/[
beaconstate, forks, helpers, signatures, state_transition],
../beacon_chain/spec/datatypes/[phase0, altair, merge],
../beacon_chain/[beacon_chain_db, beacon_clock],
../beacon_chain/eth1/eth1_monitor,
../beacon_chain/validators/validator_pool,
../beacon_chain/gossip_processing/[batch_validation, gossip_validation],
../beacon_chain/consensus_object_pools/[blockchain_dag, block_quarantine,
block_clearance, attestation_pool,
sync_committee_msg_pool],
./simutils
type Timers = enum
tBlock = "Process non-epoch slot with block"
tEpoch = "Process epoch slot with block"
tHashBlock = "Tree-hash block"
tSignBlock = "Sign block"
tAttest = "Have committee attest to block"
tSyncCommittees = "Produce sync committee actions"
tReplay = "Replay all produced blocks"
template seconds(x: uint64): timer.Duration =
timer.seconds(int(x))
func gauss(r: var Rand; mu = 0.0; sigma = 1.0): float =
# TODO This is present in Nim 1.4
const K = sqrt(2 / E)
var
a = 0.0
b = 0.0
while true:
a = rand(r, 1.0)
b = (2.0 * rand(r, 1.0) - 1.0) * K
if b * b <= -4.0 * a * a * ln(a): break
mu + sigma * (b / a)
# TODO confutils is an impenetrable black box. how can a help text be added here?
cli do(slots = SLOTS_PER_EPOCH * 6,
validators = SLOTS_PER_EPOCH * 400, # One per shard is minimum
attesterRatio {.desc: "ratio of validators that attest in each round"} = 0.82,
syncCommitteeRatio {.desc: "ratio of validators that perform sync committee actions in each round"} = 0.75,
blockRatio {.desc: "ratio of slots with blocks"} = 1.0,
replay = true):
let
(genesisState, depositContractSnapshot) = loadGenesis(validators, false)
genesisBlock = get_initial_beacon_block(genesisState[])
genesisTime = float getStateField(genesisState[], genesis_time)
var
cfg = defaultRuntimeConfig
cfg.ALTAIR_FORK_EPOCH = 64.Slot.epoch
cfg.MERGE_FORK_EPOCH = 128.Slot.epoch
echo "Starting simulation..."
let db = BeaconChainDB.new("block_sim_db")
defer: db.close()
ChainDAGRef.preInit(db, genesisState[], genesisState[], genesisBlock)
putInitialDepositContractSnapshot(db, depositContractSnapshot)
var
dag = ChainDAGRef.init(cfg, db, {})
eth1Chain = Eth1Chain.init(cfg, db)
merkleizer = depositContractSnapshot.createMerkleizer
taskpool = Taskpool.new()
verifier = BatchVerifier(rng: keys.newRng(), taskpool: taskpool)
quarantine = newClone(Quarantine.init())
attPool = AttestationPool.init(dag, quarantine)
batchCrypto = BatchCrypto.new(
keys.newRng(), eager = proc(): bool = true, taskpool)
syncCommitteePool = newClone SyncCommitteeMsgPool.init()
timers: array[Timers, RunningStat]
attesters: RunningStat
r = initRand(1)
tmpState = assignClone(dag.headState)
eth1Chain.addBlock Eth1Block(
number: Eth1BlockNumber 1,
timestamp: Eth1BlockTimestamp genesisTime,
voteData: Eth1Data(
deposit_root: merkleizer.getDepositsRoot,
deposit_count: merkleizer.getChunkCount))
let replayState = assignClone(dag.headState)
proc handleAttestations(slot: Slot) =
let
attestationHead = dag.head.atSlot(slot)
dag.withState(tmpState[], attestationHead):
let committees_per_slot =
get_committee_count_per_slot(stateData.data, slot.epoch, cache)
for committee_index in 0'u64..<committees_per_slot:
let committee = get_beacon_committee(
stateData.data, slot, committee_index.CommitteeIndex, cache)
for index_in_committee, validatorIdx in committee:
if rand(r, 1.0) <= attesterRatio:
let
data = makeAttestationData(
stateData.data, slot, committee_index.CommitteeIndex, blck.root)
sig =
get_attestation_signature(getStateField(stateData.data, fork),
getStateField(stateData.data, genesis_validators_root),
data, MockPrivKeys[validatorIdx])
var aggregation_bits = CommitteeValidatorsBits.init(committee.len)
aggregation_bits.setBit index_in_committee
attPool.addAttestation(
Attestation(
data: data,
aggregation_bits: aggregation_bits,
signature: sig.toValidatorSig()
), [validatorIdx], sig, data.slot)
proc handleSyncCommitteeActions(slot: Slot) =
type
Aggregator = object
subcommitteeIdx: SyncSubcommitteeIndex
validatorIdx: ValidatorIndex
selectionProof: ValidatorSig
let
syncCommittee = @(dag.syncCommitteeParticipants(slot + 1))
genesis_validators_root = dag.genesisValidatorsRoot
fork = dag.forkAtEpoch(slot.epoch)
messagesTime = slot.toBeaconTime(seconds(SECONDS_PER_SLOT div 3))
contributionsTime = slot.toBeaconTime(seconds(2 * SECONDS_PER_SLOT div 3))
var aggregators: seq[Aggregator]
for subcommitteeIdx in allSyncSubcommittees():
for validatorIdx in syncSubcommittee(syncCommittee, subcommitteeIdx):
if rand(r, 1.0) > syncCommitteeRatio:
continue
let
validatorPrivKey = MockPrivKeys[validatorIdx]
signature = get_sync_committee_message_signature(
fork, genesis_validators_root, slot, dag.head.root, validatorPrivKey)
msg = SyncCommitteeMessage(
slot: slot,
beacon_block_root: dag.head.root,
validator_index: uint64 validatorIdx,
signature: signature.toValidatorSig)
let res = waitFor dag.validateSyncCommitteeMessage(
batchCrypto,
syncCommitteePool,
msg,
subcommitteeIdx,
messagesTime,
false)
doAssert res.isOk
let (positions, cookedSig) = res.get()
syncCommitteePool[].addSyncCommitteeMessage(
msg.slot,
msg.beacon_block_root,
msg.validator_index,
cookedSig,
subcommitteeIdx,
positions)
let
selectionProofSig = get_sync_committee_selection_proof(
fork, genesis_validators_root, slot, uint64 subcommitteeIdx,
validatorPrivKey).toValidatorSig
if is_sync_committee_aggregator(selectionProofSig):
aggregators.add Aggregator(
subcommitteeIdx: subcommitteeIdx,
validatorIdx: validatorIdx,
selectionProof: selectionProofSig)
for aggregator in aggregators:
var contribution: SyncCommitteeContribution
let contributionWasProduced = syncCommitteePool[].produceContribution(
slot, dag.head.root, aggregator.subcommitteeIdx, contribution)
if contributionWasProduced:
let
contributionAndProof = ContributionAndProof(
aggregator_index: uint64 aggregator.validatorIdx,
contribution: contribution,
selection_proof: aggregator.selectionProof)
validatorPrivKey =
MockPrivKeys[aggregator.validatorIdx.ValidatorIndex]
signedContributionAndProof = SignedContributionAndProof(
message: contributionAndProof,
signature: get_contribution_and_proof_signature(
fork, genesis_validators_root, contributionAndProof,
validatorPrivKey).toValidatorSig)
res = waitFor dag.validateContribution(
batchCrypto,
syncCommitteePool,
signedContributionAndProof,
contributionsTime,
false)
doAssert res.isOk
syncCommitteePool[].addContribution(
signedContributionAndProof, res.get())
proc getNewBlock[T](
stateData: var StateData, slot: Slot, cache: var StateCache): T =
let
finalizedEpochRef = dag.getFinalizedEpochRef()
proposerIdx = get_beacon_proposer_index(
stateData.data, cache, getStateField(stateData.data, slot)).get()
privKey = MockPrivKeys[proposerIdx]
eth1ProposalData = eth1Chain.getBlockProposalData(
stateData.data,
finalizedEpochRef.eth1_data,
finalizedEpochRef.eth1_deposit_index)
sync_aggregate =
when T is phase0.SignedBeaconBlock:
SyncAggregate.init()
elif T is altair.SignedBeaconBlock or T is merge.SignedBeaconBlock:
syncCommitteePool[].produceSyncAggregate(dag.head.root)
else:
static: doAssert false
hashedState =
when T is phase0.SignedBeaconBlock:
addr stateData.data.phase0Data
elif T is altair.SignedBeaconBlock:
addr stateData.data.altairData
elif T is merge.SignedBeaconBlock:
addr stateData.data.mergeData
else:
static: doAssert false
message = makeBeaconBlock(
cfg,
hashedState[],
proposerIdx,
privKey.genRandaoReveal(
getStateField(stateData.data, fork),
getStateField(stateData.data, genesis_validators_root),
slot).toValidatorSig(),
eth1ProposalData.vote,
default(GraffitiBytes),
attPool.getAttestationsForBlock(stateData.data, cache),
eth1ProposalData.deposits,
BeaconBlockExits(),
sync_aggregate,
default(ExecutionPayload),
noRollback,
cache)
var
newBlock = T(
message: message.get()
)
let blockRoot = withTimerRet(timers[tHashBlock]):
hash_tree_root(newBlock.message)
newBlock.root = blockRoot
# Careful, state no longer valid after here because of the await..
newBlock.signature = withTimerRet(timers[tSignBlock]):
get_block_signature(
getStateField(stateData.data, fork),
getStateField(stateData.data, genesis_validators_root),
newBlock.message.slot,
blockRoot, privKey).toValidatorSig()
newBlock
proc proposePhase0Block(slot: Slot) =
if rand(r, 1.0) > blockRatio:
return
dag.withState(tmpState[], dag.head.atSlot(slot)):
let
newBlock = getNewBlock[phase0.SignedBeaconBlock](stateData, slot, cache)
added = dag.addHeadBlock(verifier, newBlock) do (
blckRef: BlockRef, signedBlock: phase0.TrustedSignedBeaconBlock,
epochRef: EpochRef):
# Callback add to fork choice if valid
attPool.addForkChoice(
epochRef, blckRef, signedBlock.message, blckRef.slot)
blck() = added[]
dag.updateHead(added[], quarantine[])
if dag.needStateCachesAndForkChoicePruning():
dag.pruneStateCachesDAG()
attPool.prune()
proc proposeAltairBlock(slot: Slot) =
if rand(r, 1.0) > blockRatio:
return
dag.withState(tmpState[], dag.head.atSlot(slot)):
let
newBlock = getNewBlock[altair.SignedBeaconBlock](stateData, slot, cache)
added = dag.addHeadBlock(verifier, newBlock) do (
blckRef: BlockRef, signedBlock: altair.TrustedSignedBeaconBlock,
epochRef: EpochRef):
# Callback add to fork choice if valid
attPool.addForkChoice(
epochRef, blckRef, signedBlock.message, blckRef.slot)
blck() = added[]
dag.updateHead(added[], quarantine[])
if dag.needStateCachesAndForkChoicePruning():
dag.pruneStateCachesDAG()
attPool.prune()
proc proposeMergeBlock(slot: Slot) =
if rand(r, 1.0) > blockRatio:
return
dag.withState(tmpState[], dag.head.atSlot(slot)):
let
newBlock = getNewBlock[merge.SignedBeaconBlock](stateData, slot, cache)
added = dag.addHeadBlock(verifier, newBlock) do (
blckRef: BlockRef, signedBlock: merge.TrustedSignedBeaconBlock,
epochRef: EpochRef):
# Callback add to fork choice if valid
attPool.addForkChoice(
epochRef, blckRef, signedBlock.message, blckRef.slot)
blck() = added[]
dag.updateHead(added[], quarantine[])
if dag.needStateCachesAndForkChoicePruning():
dag.pruneStateCachesDAG()
attPool.prune()
var
lastEth1BlockAt = genesisTime
eth1BlockNum = 1000
for i in 0..<slots:
let
slot = Slot(i + 1)
t =
if slot.isEpoch: tEpoch
else: tBlock
now = genesisTime + float(slot * SECONDS_PER_SLOT)
while true:
let nextBlockTime = lastEth1BlockAt +
max(1.0, gauss(r, float defaultRuntimeConfig.SECONDS_PER_ETH1_BLOCK, 3.0))
if nextBlockTime > now:
break
inc eth1BlockNum
var eth1Block = Eth1Block(
number: Eth1BlockNumber eth1BlockNum,
timestamp: Eth1BlockTimestamp nextBlockTime,
voteData: Eth1Data(
block_hash: makeFakeHash(eth1BlockNum)))
let newDeposits = int clamp(gauss(r, 5.0, 8.0), 0.0, 1000.0)
for i in 0 ..< newDeposits:
let validatorIdx = merkleizer.getChunkCount.int
let d = makeDeposit(validatorIdx, {skipBLSValidation})
eth1Block.deposits.add d
merkleizer.addChunk hash_tree_root(d).data
eth1Block.voteData.deposit_root = merkleizer.getDepositsRoot
eth1Block.voteData.deposit_count = merkleizer.getChunkCount
eth1Chain.addBlock eth1Block
lastEth1BlockAt = nextBlockTime
if blockRatio > 0.0:
withTimer(timers[t]):
case dag.cfg.stateForkAtEpoch(slot.epoch)
of BeaconStateFork.Merge: proposeMergeBlock(slot)
of BeaconStateFork.Altair: proposeAltairBlock(slot)
of BeaconStateFork.Phase0: proposePhase0Block(slot)
if attesterRatio > 0.0:
withTimer(timers[tAttest]):
handleAttestations(slot)
if syncCommitteeRatio > 0.0:
withTimer(timers[tSyncCommittees]):
handleSyncCommitteeActions(slot)
syncCommitteePool[].pruneData(slot)
# TODO if attestation pool was smarter, it would include older attestations
# too!
verifyConsensus(dag.headState.data, attesterRatio * blockRatio)
if t == tEpoch:
echo &". slot: {shortLog(slot)} ",
&"epoch: {shortLog(slot.compute_epoch_at_slot)}"
else:
write(stdout, ".")
flushFile(stdout)
if replay:
withTimer(timers[tReplay]):
var cache = StateCache()
dag.updateStateData(
replayState[], dag.head.atSlot(Slot(slots)), false, cache)
echo "Done!"
printTimers(dag.headState.data, attesters, true, timers)