nimbus-eth2/beacon_chain/validator_client/duties_service.nim

752 lines
27 KiB
Nim

# beacon_chain
# Copyright (c) 2021-2022 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.
import std/[sets, sequtils]
import chronicles
import common, api, block_service
const
ServiceName = "duties_service"
SUBSCRIPTION_LOOKAHEAD_EPOCHS* = 4'u64
logScope: service = ServiceName
type
DutiesServiceLoop* = enum
AttesterLoop, ProposerLoop, IndicesLoop, SyncCommitteeLoop,
ProposerPreparationLoop, ValidatorRegisterLoop
chronicles.formatIt(DutiesServiceLoop):
case it
of AttesterLoop: "attester_loop"
of ProposerLoop: "proposer_loop"
of IndicesLoop: "index_loop"
of SyncCommitteeLoop: "sync_committee_loop"
of ProposerPreparationLoop: "proposer_prepare_loop"
of ValidatorRegisterLoop: "validator_register_loop"
proc checkDuty(duty: RestAttesterDuty): bool =
(duty.committee_length <= MAX_VALIDATORS_PER_COMMITTEE) and
(uint64(duty.committee_index) < MAX_COMMITTEES_PER_SLOT) and
(uint64(duty.validator_committee_index) < duty.committee_length) and
(uint64(duty.validator_index) <= VALIDATOR_REGISTRY_LIMIT)
proc checkSyncDuty(duty: RestSyncCommitteeDuty): bool =
uint64(duty.validator_index) <= VALIDATOR_REGISTRY_LIMIT
proc pollForValidatorIndices*(vc: ValidatorClientRef) {.async.} =
let validatorIdents =
block:
var res: seq[ValidatorIdent]
for validator in vc.attachedValidators[].items():
if validator.needsUpdate():
res.add(ValidatorIdent.init(validator.pubkey))
res
var validators: seq[RestValidator]
var offset = 0
while offset < len(validatorIdents):
let arraySize = min(ClientMaximumValidatorIds, len(validatorIdents))
let idents =
block:
var res = newSeq[ValidatorIdent](arraySize)
var k = 0
for i in offset ..< arraySize:
res[k] = validatorIdents[i]
inc(k)
res
let res =
try:
await vc.getValidators(idents, ApiStrategyKind.First)
except ValidatorApiError as exc:
warn "Unable to get head state's validator information",
reason = exc.getFailureReason()
return
except CancelledError as exc:
debug "Validator's indices processing was interrupted"
raise exc
except CatchableError as exc:
error "Unexpected error occurred while getting validator information",
err_name = exc.name, err_msg = exc.msg
return
for item in res:
validators.add(item)
offset += arraySize
var
missing: seq[string]
updated: seq[string]
list: seq[AttachedValidator]
for item in validators:
let validator = vc.attachedValidators[].getValidator(item.validator.pubkey)
if validator.isNone():
missing.add(validatorLog(item.validator.pubkey, item.index))
else:
validator.get().updateValidator(Opt.some ValidatorAndIndex(
index: item.index,
validator: item.validator))
updated.add(validatorLog(item.validator.pubkey, item.index))
list.add(validator.get())
if len(updated) > 0:
info "Validator indices updated",
pending = len(validatorIdents) - len(updated),
missing = len(missing),
updated = len(updated)
trace "Validator indices update dump", missing_validators = missing,
updated_validators = updated
vc.indicesAvailable.fire()
proc pollForAttesterDuties*(vc: ValidatorClientRef,
epoch: Epoch): Future[int] {.async.} =
let validatorIndices =
block:
var res: seq[ValidatorIndex]
for index in vc.attachedValidators[].indices():
res.add(index)
res
if validatorIndices.len == 0:
return 0
var duties: seq[RestAttesterDuty]
var currentRoot: Option[Eth2Digest]
var offset = 0
while offset < len(validatorIndices):
let arraySize = min(DutiesMaximumValidatorIds, len(validatorIndices))
# We use `DutiesMaximumValidatorIds` here because validator ids are sent
# in HTTP request body and NOT in HTTP request headers.
let indices =
block:
var res = newSeq[ValidatorIndex](arraySize)
var k = 0
for i in offset ..< arraySize:
res[k] = validatorIndices[i]
inc(k)
res
let res =
try:
await vc.getAttesterDuties(epoch, indices, ApiStrategyKind.First)
except ValidatorApiError as exc:
warn "Unable to get attester duties", epoch = epoch,
reason = exc.getFailureReason()
return 0
except CancelledError as exc:
debug "Attester duties processing was interrupted"
raise exc
except CatchableError as exc:
error "Unexpected error occured while getting attester duties",
epoch = epoch, err_name = exc.name, err_msg = exc.msg
return 0
if currentRoot.isNone():
# First request
currentRoot = some(res.dependent_root)
else:
if currentRoot.get() != res.dependent_root:
# `dependent_root` must be equal for all requests/response, if it got
# changed it means that some reorg was happened in beacon node and we
# should re-request all queries again.
offset = 0
duties.setLen(0)
currentRoot = none[Eth2Digest]()
continue
for item in res.data:
duties.add(item)
offset += arraySize
let
relevantDuties = duties.filterIt(
checkDuty(it) and (it.pubkey in vc.attachedValidators[])
)
genesisRoot = vc.beaconGenesis.genesis_validators_root
let addOrReplaceItems =
block:
var alreadyWarned = false
var res: seq[tuple[epoch: Epoch, duty: RestAttesterDuty]]
for duty in relevantDuties:
let map = vc.attesters.getOrDefault(duty.pubkey)
let epochDuty = map.duties.getOrDefault(epoch, DefaultDutyAndProof)
if not(epochDuty.isDefault()):
if epochDuty.dependentRoot != currentRoot.get():
res.add((epoch, duty))
if not(alreadyWarned):
warn "Attester duties re-organization",
prior_dependent_root = epochDuty.dependentRoot,
dependent_root = currentRoot.get()
alreadyWarned = true
else:
info "Received new attester duty", duty, epoch = epoch,
dependent_root = currentRoot.get()
res.add((epoch, duty))
res
if len(addOrReplaceItems) > 0:
var pendingRequests: seq[Future[SignatureResult]]
var validators: seq[AttachedValidator]
for item in addOrReplaceItems:
let validator =
vc.attachedValidators[].getValidator(item.duty.pubkey).valueOr:
continue
let fork = vc.forkAtEpoch(item.duty.slot.epoch)
let future = validator.getSlotSignature(
fork, genesisRoot, item.duty.slot)
pendingRequests.add(future)
validators.add(validator)
try:
await allFutures(pendingRequests)
except CancelledError as exc:
var pendingCancel: seq[Future[void]]
for future in pendingRequests:
if not(future.finished()):
pendingCancel.add(future.cancelAndWait())
await allFutures(pendingCancel)
raise exc
for index, fut in pendingRequests:
let item = addOrReplaceItems[index]
let dap =
if fut.done():
let sigRes = fut.read()
if sigRes.isErr():
warn "Unable to create slot signature using remote signer",
validator = shortLog(validators[index]),
error_msg = sigRes.error()
DutyAndProof.init(item.epoch, currentRoot.get(), item.duty,
none[ValidatorSig]())
else:
DutyAndProof.init(item.epoch, currentRoot.get(), item.duty,
some(sigRes.get()))
else:
DutyAndProof.init(item.epoch, currentRoot.get(), item.duty,
none[ValidatorSig]())
var validatorDuties = vc.attesters.getOrDefault(item.duty.pubkey)
validatorDuties.duties[item.epoch] = dap
vc.attesters[item.duty.pubkey] = validatorDuties
return len(addOrReplaceItems)
proc pruneSyncCommitteeDuties*(vc: ValidatorClientRef, slot: Slot) =
if slot.is_sync_committee_period():
var newSyncCommitteeDuties: SyncCommitteeDutiesMap
let epoch = slot.epoch()
for key, item in vc.syncCommitteeDuties:
var currentPeriodDuties = EpochSyncDuties()
for epochKey, epochDuty in item.duties:
if epochKey >= epoch:
currentPeriodDuties.duties[epochKey] = epochDuty
newSyncCommitteeDuties[key] = currentPeriodDuties
vc.syncCommitteeDuties = newSyncCommitteeDuties
proc pollForSyncCommitteeDuties*(vc: ValidatorClientRef,
epoch: Epoch): Future[int] {.async.} =
let validatorIndices = toSeq(vc.attachedValidators[].indices())
var
filteredDuties: seq[RestSyncCommitteeDuty]
offset = 0
remainingItems = len(validatorIndices)
while offset < len(validatorIndices):
let
arraySize = min(DutiesMaximumValidatorIds, remainingItems)
# We use `DutiesMaximumValidatorIds` here because validator ids are sent
# in HTTP request body and NOT in HTTP request headers.
indices = validatorIndices[offset ..< (offset + arraySize)]
res =
try:
await vc.getSyncCommitteeDuties(epoch, indices, ApiStrategyKind.First)
except ValidatorApiError as exc:
warn "Unable to get sync committee duties", epoch = epoch,
reason = exc.getFailureReason()
return 0
except CancelledError as exc:
debug "Sync committee duties processing was interrupted"
raise exc
except CatchableError as exc:
error "Unexpected error occurred while getting sync committee duties",
epoch = epoch, err_name = exc.name, err_msg = exc.msg
return 0
for item in res.data:
if checkSyncDuty(item) and (item.pubkey in vc.attachedValidators[]):
filteredDuties.add(item)
offset += arraySize
remainingItems -= arraySize
let
relevantDuties =
block:
var res: seq[SyncCommitteeDuty]
for duty in filteredDuties:
for validatorSyncCommitteeIndex in
duty.validator_sync_committee_indices:
res.add(SyncCommitteeDuty(
pubkey: duty.pubkey,
validator_index: duty.validator_index,
validator_sync_committee_index: validatorSyncCommitteeIndex))
res
fork = vc.forkAtEpoch(epoch)
let addOrReplaceItems =
block:
var alreadyWarned = false
var res: seq[tuple[epoch: Epoch, duty: SyncCommitteeDuty]]
for duty in relevantDuties:
var dutyFound = false
vc.syncCommitteeDuties.withValue(duty.pubkey, map):
map.duties.withValue(epoch, epochDuty):
if epochDuty[] != duty:
dutyFound = true
if dutyFound and not alreadyWarned:
info "Sync committee duties re-organization", duty, epoch
alreadyWarned = true
res.add((epoch, duty))
res
if len(addOrReplaceItems) > 0:
for epoch, duty in items(addOrReplaceItems):
var validatorDuties =
vc.syncCommitteeDuties.getOrDefault(duty.pubkey)
validatorDuties.duties[epoch] = duty
vc.syncCommitteeDuties[duty.pubkey] = validatorDuties
return len(addOrReplaceItems)
proc pruneAttesterDuties(vc: ValidatorClientRef, epoch: Epoch) =
var attesters: AttesterMap
for key, item in vc.attesters:
var v = EpochDuties()
for epochKey, epochDuty in item.duties:
if (epochKey + HISTORICAL_DUTIES_EPOCHS) >= epoch:
v.duties[epochKey] = epochDuty
else:
debug "Attester duties for the epoch has been pruned", validator = key,
epoch = epochKey, loop = AttesterLoop
attesters[key] = v
vc.attesters = attesters
proc pollForAttesterDuties*(vc: ValidatorClientRef) {.async.} =
## Query the beacon node for attestation duties for all known validators.
##
## This function will perform (in the following order):
##
## 1. Poll for current-epoch duties and update the local `attesters` map.
## 2. Poll for next-epoch duties and update the local `attesters` map.
## 3. Push out any attestation subnet subscriptions to the BN.
let sres = vc.getCurrentSlot()
if sres.isSome():
let
currentSlot = sres.get()
currentEpoch = currentSlot.epoch()
nextEpoch = currentEpoch + 1'u64
if vc.attachedValidators[].count() != 0:
var counts: array[2, tuple[epoch: Epoch, count: int]]
counts[0] = (currentEpoch, await vc.pollForAttesterDuties(currentEpoch))
counts[1] = (nextEpoch, await vc.pollForAttesterDuties(nextEpoch))
if (counts[0].count == 0) and (counts[1].count == 0):
debug "No new attester's duties received", slot = currentSlot
let subscriptions =
block:
var res: seq[RestCommitteeSubscription]
for item in counts:
if item.count > 0:
for duty in vc.attesterDutiesForEpoch(item.epoch):
if currentSlot + SUBSCRIPTION_BUFFER_SLOTS < duty.data.slot:
let isAggregator =
if duty.slotSig.isSome():
is_aggregator(duty.data.committee_length,
duty.slotSig.get())
else:
false
let sub = RestCommitteeSubscription(
validator_index: duty.data.validator_index,
committee_index: duty.data.committee_index,
committees_at_slot: duty.data.committees_at_slot,
slot: duty.data.slot,
is_aggregator: isAggregator
)
res.add(sub)
res
if len(subscriptions) > 0:
let res = await vc.prepareBeaconCommitteeSubnet(subscriptions)
if res == 0:
warn "Failed to subscribe validators to beacon committee subnets",
slot = currentSlot, epoch = currentEpoch,
subscriptions_count = len(subscriptions)
vc.pruneAttesterDuties(currentEpoch)
proc pollForSyncCommitteeDuties* (vc: ValidatorClientRef) {.async.} =
let sres = vc.getCurrentSlot()
if sres.isSome():
let
currentSlot = sres.get()
currentEpoch = currentSlot.epoch()
if vc.attachedValidators[].count() != 0:
let
dutyPeriods =
block:
var res: seq[tuple[epoch: Epoch, period: SyncCommitteePeriod]]
let
currentPeriod = currentSlot.sync_committee_period()
lookaheadSlot = currentSlot +
SUBSCRIPTION_LOOKAHEAD_EPOCHS * SLOTS_PER_EPOCH
lookaheadPeriod = lookaheadSlot.sync_committee_period()
res.add(
(epoch: currentSlot.epoch(),
period: currentPeriod)
)
if lookAheadPeriod > currentPeriod:
res.add(
(epoch: lookaheadPeriod.start_epoch(),
period: lookAheadPeriod)
)
res
(counts, total) =
block:
var res: seq[tuple[epoch: Epoch, period: SyncCommitteePeriod,
count: int]]
var total = 0
if len(dutyPeriods) > 0:
for (epoch, period) in dutyPeriods:
let count = await vc.pollForSyncCommitteeDuties(epoch)
res.add((epoch: epoch, period: period, count: count))
total += count
(res, total)
if total == 0:
debug "No new sync committee member's duties received",
slot = currentSlot
let subscriptions =
block:
var res: seq[RestSyncCommitteeSubscription]
for item in counts:
if item.count > 0:
let untilEpoch = start_epoch(item.period + 1'u64)
let subscriptionsInfo =
vc.syncMembersSubscriptionInfoForEpoch(item.epoch)
for subInfo in subscriptionsInfo:
let sub = RestSyncCommitteeSubscription(
validator_index: subInfo.validator_index,
sync_committee_indices:
subInfo.validator_sync_committee_indices,
until_epoch: untilEpoch
)
res.add(sub)
res
if len(subscriptions) > 0:
let res = await vc.prepareSyncCommitteeSubnets(subscriptions)
if res != 0:
warn "Failed to subscribe validators to sync committee subnets",
slot = currentSlot, epoch = currentEpoch,
subscriptions_count = len(subscriptions)
vc.pruneSyncCommitteeDuties(currentSlot)
proc pruneBeaconProposers(vc: ValidatorClientRef, epoch: Epoch) =
var proposers: ProposerMap
for epochKey, data in vc.proposers:
if (epochKey + HISTORICAL_DUTIES_EPOCHS) >= epoch:
proposers[epochKey] = data
else:
debug "Proposer duty has been pruned", epoch = epochKey,
loop = ProposerLoop
vc.proposers = proposers
proc pollForBeaconProposers*(vc: ValidatorClientRef) {.async.} =
let sres = vc.getCurrentSlot()
if sres.isSome():
let
currentSlot = sres.get()
currentEpoch = currentSlot.epoch()
if vc.attachedValidators[].count() != 0:
try:
let res = await vc.getProposerDuties(currentEpoch,
ApiStrategyKind.First)
let
dependentRoot = res.dependent_root
duties = res.data
relevantDuties = duties.filterIt(it.pubkey in vc.attachedValidators[])
if len(relevantDuties) > 0:
vc.addOrReplaceProposers(currentEpoch, dependentRoot, relevantDuties)
else:
debug "No relevant proposer duties received", slot = currentSlot,
duties_count = len(duties)
except ValidatorApiError as exc:
warn "Unable to get proposer duties", slot = currentSlot,
epoch = currentEpoch, reason = exc.getFailureReason()
except CancelledError as exc:
debug "Proposer duties processing was interrupted"
raise exc
except CatchableError as exc:
debug "Unexpected error occured while getting proposer duties",
slot = currentSlot, epoch = currentEpoch, err_name = exc.name,
err_msg = exc.msg
vc.pruneBeaconProposers(currentEpoch)
proc prepareBeaconProposers*(service: DutiesServiceRef) {.async.} =
let vc = service.client
let sres = vc.getCurrentSlot()
if sres.isSome():
let
currentSlot = sres.get()
currentEpoch = currentSlot.epoch()
proposers = vc.prepareProposersList(currentEpoch)
if len(proposers) > 0:
let count =
try:
await prepareBeaconProposer(vc, proposers)
except ValidatorApiError as exc:
warn "Unable to prepare beacon proposers", slot = currentSlot,
epoch = currentEpoch, err_name = exc.name,
err_msg = exc.msg, reason = exc.getFailureReason()
0
except CancelledError as exc:
debug "Beacon proposer preparation processing was interrupted"
raise exc
except CatchableError as exc:
error "Unexpected error occured while preparing beacon proposers",
slot = currentSlot, epoch = currentEpoch, err_name = exc.name,
err_msg = exc.msg
0
debug "Beacon proposers prepared",
validators_count = vc.attachedValidators[].count(),
proposers_count = len(proposers),
prepared_count = count
proc registerValidators*(service: DutiesServiceRef) {.async.} =
let vc = service.client
let sres = vc.getCurrentSlot()
var default: seq[SignedValidatorRegistrationV1]
if sres.isSome():
let
genesisFork = vc.forks[0]
currentSlot = sres.get()
registrations =
try:
await vc.prepareRegistrationList(getTime(), genesisFork)
except CancelledError as exc:
debug "Validator registration preparation was interrupted",
slot = currentSlot, fork = genesisFork
raise exc
except CatchableError as exc:
error "Unexpected error occured while preparing validators " &
"registration data", slot = currentSlot, fork = genesisFork,
err_name = exc.name, err_msg = exc.msg
default
let count =
if len(registrations) > 0:
try:
await registerValidator(vc, registrations)
except ValidatorApiError as exc:
warn "Unable to register validators", slot = currentSlot,
fork = genesisFork, err_name = exc.name,
err_msg = exc.msg, reason = exc.getFailureReason()
0
except CancelledError as exc:
debug "Validator registration was interrupted", slot = currentSlot,
fork = genesisFork
raise exc
except CatchableError as exc:
error "Unexpected error occured while registering validators",
slot = currentSlot, fork = genesisFork, err_name = exc.name,
err_msg = exc.msg
0
else:
0
if count > 0:
debug "Validators registered", slot = currentSlot,
beacon_nodes_count = count, registrations = len(registrations),
validators_count = vc.attachedValidators[].count()
proc waitForNextSlot(service: DutiesServiceRef,
serviceLoop: DutiesServiceLoop) {.async.} =
let vc = service.client
let sleepTime = vc.beaconClock.durationToNextSlot()
await sleepAsync(sleepTime)
proc attesterDutiesLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
debug "Attester duties loop waiting for fork schedule update"
await vc.forksAvailable.wait()
doAssert(len(vc.forks) > 0, "Fork schedule must not be empty at this point")
while true:
await vc.pollForAttesterDuties()
await service.waitForNextSlot(AttesterLoop)
proc proposerDutiesLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
debug "Proposer duties loop waiting for fork schedule update"
await vc.forksAvailable.wait()
doAssert(len(vc.forks) > 0, "Fork schedule must not be empty at this point")
while true:
await vc.pollForBeaconProposers()
await service.waitForNextSlot(ProposerLoop)
proc validatorIndexLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
while true:
await vc.pollForValidatorIndices()
await service.waitForNextSlot(IndicesLoop)
proc proposerPreparationsLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
debug "Beacon proposer preparation loop waiting for validator indices update"
await vc.indicesAvailable.wait()
while true:
await service.prepareBeaconProposers()
await service.waitForNextSlot(ProposerPreparationLoop)
proc validatorRegisterLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
doAssert(vc.config.payloadBuilderEnable)
debug "Validator registration loop is waiting for initialization"
await allFutures(vc.indicesAvailable.wait(), vc.forksAvailable.wait())
while true:
await service.registerValidators()
await service.waitForNextSlot(ValidatorRegisterLoop)
proc syncCommitteeDutiesLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
debug "Sync committee duties loop waiting for fork schedule update"
await vc.forksAvailable.wait()
doAssert(len(vc.forks) > 0, "Fork schedule must not be empty at this point")
while true:
await vc.pollForSyncCommitteeDuties()
await service.waitForNextSlot(SyncCommitteeLoop)
template checkAndRestart(serviceLoop: DutiesServiceLoop,
future: Future[void], body: untyped): untyped =
if future.finished():
if future.failed():
let error = future.readError()
debug "The loop ended unexpectedly with an error",
error_name = error.name, error_msg = error.msg, loop = serviceLoop
elif future.cancelled():
debug "The loop was interrupted", loop = serviceLoop
else:
debug "The loop is finished unexpectedly without an error",
loop = serviceLoop
future = body
proc mainLoop(service: DutiesServiceRef) {.async.} =
let vc = service.client
service.state = ServiceState.Running
debug "Service started"
var
attestFut = service.attesterDutiesLoop()
proposeFut = service.proposerDutiesLoop()
indicesFut = service.validatorIndexLoop()
syncFut = service.syncCommitteeDutiesLoop()
prepareFut = service.proposerPreparationsLoop()
registerFut =
if vc.config.payloadBuilderEnable:
service.validatorRegisterLoop()
else:
nil
while true:
# This loop could look much more nicer/better, when
# https://github.com/nim-lang/Nim/issues/19911 will be fixed, so it could
# become safe to combine loops, breaks and exception handlers.
let breakLoop =
try:
var futures = @[FutureBase(attestFut), FutureBase(proposeFut),
FutureBase(indicesFut), FutureBase(syncFut),
FutureBase(prepareFut)]
if not(isNil(registerFut)): futures.add(FutureBase(registerFut))
discard await race(futures)
checkAndRestart(AttesterLoop, attestFut, service.attesterDutiesLoop())
checkAndRestart(ProposerLoop, proposeFut, service.proposerDutiesLoop())
checkAndRestart(IndicesLoop, indicesFut, service.validatorIndexLoop())
checkAndRestart(SyncCommitteeLoop, syncFut,
service.syncCommitteeDutiesLoop())
checkAndRestart(ProposerPreparationLoop, prepareFut,
service.proposerPreparationsLoop())
if not(isNil(registerFut)):
checkAndRestart(ValidatorRegisterLoop, registerFut,
service.validatorRegisterLoop())
false
except CancelledError:
debug "Service interrupted"
var pending: seq[Future[void]]
if not(attestFut.finished()):
pending.add(attestFut.cancelAndWait())
if not(proposeFut.finished()):
pending.add(proposeFut.cancelAndWait())
if not(indicesFut.finished()):
pending.add(indicesFut.cancelAndWait())
if not(syncFut.finished()):
pending.add(syncFut.cancelAndWait())
if not(prepareFut.finished()):
pending.add(prepareFut.cancelAndWait())
if not(isNil(registerFut)) and not(registerFut.finished()):
pending.add(registerFut.cancelAndWait())
await allFutures(pending)
true
except CatchableError as exc:
warn "Service crashed with unexpected error", err_name = exc.name,
err_msg = exc.msg
true
if breakLoop:
break
proc init*(t: typedesc[DutiesServiceRef],
vc: ValidatorClientRef): Future[DutiesServiceRef] {.async.} =
logScope: service = ServiceName
let res = DutiesServiceRef(name: ServiceName,
client: vc, state: ServiceState.Initialized)
debug "Initializing service"
# We query for indices first, to avoid empty queries for duties.
await vc.pollForValidatorIndices()
return res
proc start*(service: DutiesServiceRef) =
service.lifeFut = mainLoop(service)