nimbus-eth2/beacon_chain/request_manager.nim

168 lines
5.6 KiB
Nim

import options, sequtils, strutils
import chronos, chronicles
import spec/[datatypes, digest], eth2_network, beacon_node_types, sync_protocol,
sync_manager, ssz/merkleization, ./eth2_processor
export sync_manager
logScope:
topics = "requman"
const
SYNC_MAX_REQUESTED_BLOCKS* = 32 # Spec allows up to MAX_REQUEST_BLOCKS.
## Maximum number of blocks which will be requested in each
## `beaconBlocksByRoot` invocation.
PARALLEL_REQUESTS* = 2
## Number of peers we using to resolve our request.
type
RequestManager* = object
network*: Eth2Node
inpQueue*: AsyncQueue[FetchRecord]
outQueue*: AsyncQueue[BlockEntry]
loopFuture: Future[void]
func shortLog*(x: seq[Eth2Digest]): string =
"[" & x.mapIt(shortLog(it)).join(", ") & "]"
func shortLog*(x: seq[FetchRecord]): string =
"[" & x.mapIt(shortLog(it.root)).join(", ") & "]"
proc init*(T: type RequestManager, network: Eth2Node,
outputQueue: AsyncQueue[BlockEntry]): RequestManager =
RequestManager(
network: network,
inpQueue: newAsyncQueue[FetchRecord](),
outQueue: outputQueue
)
proc checkResponse(roots: openArray[Eth2Digest],
blocks: openArray[SignedBeaconBlock]): bool =
## This procedure checks peer's response.
var checks = @roots
if len(blocks) > len(roots):
return false
for blk in blocks:
let res = checks.find(blk.root)
if res == -1:
return false
else:
checks.del(res)
return true
proc validate(rman: RequestManager,
b: SignedBeaconBlock): Future[Result[void, BlockError]] {.async.} =
let sblock = SyncBlock(
blk: b,
resfut: newFuture[Result[void, BlockError]]("request.manager.validate")
)
await rman.outQueue.addLast(BlockEntry(v: sblock))
return await sblock.resfut
proc fetchAncestorBlocksFromNetwork(rman: RequestManager,
items: seq[Eth2Digest]) {.async.} =
var peer: Peer
try:
peer = await rman.network.peerPool.acquire()
debug "Requesting blocks by root", peer = peer, blocks = shortLog(items),
peer_score = peer.getScore()
let blocks = await peer.beaconBlocksByRoot(BlockRootsList items)
if blocks.isOk:
let ublocks = blocks.get()
if checkResponse(items, ublocks):
var res: Result[void, BlockError]
if len(ublocks) > 0:
for b in ublocks:
res = await rman.validate(b)
# We are ignoring errors:
# `BlockError.MissingParent` - because the order of the blocks that
# we requested may be different from the order in which we need
# these blocks to apply.
# `BlockError.Old`, `BlockError.Duplicate` and `BlockError.Unviable`
# errors could occur due to the concurrent/parallel requests we are
# made.
if res.isErr() and (res.error == BlockError.Invalid):
# We stop processing blocks further to avoid DoS attack with big
# chunk of incorrect blocks.
break
else:
res = Result[void, BlockError].ok()
if res.isOk():
if len(ublocks) > 0:
# We reward peer only if it returns something.
peer.updateScore(PeerScoreGoodBlocks)
else:
# We are not penalizing other errors because of the reasons described
# above.
if res.error == BlockError.Invalid:
peer.updateScore(PeerScoreBadBlocks)
else:
peer.updateScore(PeerScoreBadResponse)
else:
peer.updateScore(PeerScoreNoBlocks)
except CancelledError as exc:
raise exc
except CatchableError as exc:
peer.updateScore(PeerScoreNoBlocks)
debug "Error while fetching ancestor blocks", exc = exc.msg,
items = shortLog(items), peer = peer, peer_score = peer.getScore()
raise exc
finally:
if not(isNil(peer)):
rman.network.peerPool.release(peer)
proc requestManagerLoop(rman: RequestManager) {.async.} =
var rootList = newSeq[Eth2Digest]()
var workers = newSeq[Future[void]](PARALLEL_REQUESTS)
while true:
try:
rootList.setLen(0)
let req = await rman.inpQueue.popFirst()
rootList.add(req.root)
var count = min(SYNC_MAX_REQUESTED_BLOCKS - 1, len(rman.inpQueue))
while count > 0:
rootList.add(rman.inpQueue.popFirstNoWait().root)
dec(count)
let start = SyncMoment.now(Slot(0))
for i in 0 ..< PARALLEL_REQUESTS:
workers[i] = rman.fetchAncestorBlocksFromNetwork(rootList)
# We do not care about
await allFutures(workers)
let finish = SyncMoment.now(Slot(0) + uint64(len(rootList)))
var succeed = 0
for worker in workers:
if worker.finished() and not(worker.failed()):
inc(succeed)
debug "Request manager tick", blocks_count = len(rootList),
succeed = succeed,
failed = (len(workers) - succeed),
queue_size = len(rman.inpQueue),
sync_speed = speed(start, finish)
except CatchableError as exc:
debug "Got a problem in request manager", exc = exc.msg
proc start*(rman: var RequestManager) =
## Start Request Manager's loop.
rman.loopFuture = rman.requestManagerLoop()
proc stop*(rman: RequestManager) =
## Stop Request Manager's loop.
if not(isNil(rman.loopFuture)):
rman.loopFuture.cancel()
proc fetchAncestorBlocks*(rman: RequestManager, roots: seq[FetchRecord]) =
## Enqueue list missing blocks roots ``roots`` for download by
## Request Manager ``rman``.
for item in roots:
rman.inpQueue.addLastNoWait(item)