nimbus-eth1/nimbus/sync/flare/worker_config.nim

139 lines
5.4 KiB
Nim

# Nimbus
# Copyright (c) 2021-2024 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
pkg/chronos
const
enableTicker* = true
## Log regular status updates similar to metrics. Great for debugging.
runsThisManyPeersOnly* = 8
## Set to `1` for running a single peer only at a time. Great for debugging.
##
## Otherwise, this setting limits the number of peers accepted by the
## `runStart()` peer initialiser. When testing with an unlimited number of
## peers with some double digit number of connected peers, the observed
## response times when fetching headers seemed to degrade considerable into
## seconds (rather than ms.) This will be further looked at to be confirmed
## or rejected as insignificant.
##
## FIXME: This setting has priority over the `maxPeers` setting of the
## `FlareSyncRef.init()` initaliser. This might be harmonised at
## a later stage.
# ----------------------
metricsUpdateInterval* = chronos.seconds(10)
## Wait at least this time before next update
daemonWaitInterval* = chronos.seconds(10)
## Some waiting time at the end of the daemon task which always lingers
## in the background.
workerIdleWaitInterval* = chronos.seconds(10)
## Sleep some time in multi-mode if there is nothing to do
asyncThreadSwitchTimeSlot* = chronos.nanoseconds(10)
## Nano-sleep to allows pseudo/async thread switch
# ----------------------
nFetchHeadersRequest* = 1_024
## Number of headers that will be requested with a single `eth/xx` message.
##
## On `Geth`, responses to larger requests are all truncted to 1024 header
## entries (see `Geth` constant `maxHeadersServe`.)
fetchHeadersReqThresholdZombie* = chronos.seconds(2)
fetchHeadersReqThresholdCount* = 3
## Response time allowance. If the response time for the set of headers
## exceeds this threshold for more than `fetchHeadersReqThresholdCount`
## times in a row, then this peer will be banned for a while.
fetchHeadersReqMinResponsePC* = 10
## Some peers only returned one header at a time. If these peers sit on a
## farm, they might collectively slow down the download process. So this
## constant sets a percentage of minimum headers needed to return so that
## the peers is not treated as a slow responder (see above for slow
## responder count.)
nFetchHeadersBatch* = 8 * nFetchHeadersRequest
## Length of the request/stage batch. Several headers are consecutively
## fetched and stashed together as a single record on the staged queue.
headersStagedQueueLengthLwm* = 32
## Limit the number of records in the staged headers queue.
##
## Queue entries start accumulating if one peer stalls while fetching the
## top chain so leaving a gap. This gap must be filled first before
## inserting the queue into a contiguous chain of headers.
##
## This low-water mark tryggers the system to do some **magic** to mitigate
## the above problem. Currently the **magic** is to let (pseudo) threads
## terminate and then restart all over again.
headersStagedQueueLengthHwm* = 48
## If this size is exceeded, the staged queue is flushed and resized to
## `headersStagedQueueLengthLwm-1` entries. Then contents is re-fetched
## from scratch.
# ----------------------
nFetchBodiesRequest* = 128
## Similar to `nFetchHeadersRequest`
fetchBodiesReqThresholdZombie* = chronos.seconds(2)
fetchBodiesReqThresholdCount* = 3
## Similar to `fetchHeadersReqThreshold*`
fetchBodiesReqMinResponsePC* = 10
## Similar to `fetchHeadersReqMinResponsePC`
nFetchBodiesBatchDefault* = 6 * nFetchBodiesRequest
## Similar to `nFetchHeadersBatch`
##
## This value can be overridden with a smaller value which must be at
## least `nFetchBodiesRequest`.
blocksStagedQueueLenMaxDefault* = 16
## Maximum number of staged header + bodies blocks records to be filled. If
## this size is reached, the process stops with staging with the exception
## of the lowest blockes (in case there is a gap.)
##
## This value might be adjusted with a larger value if
## `nFetchBodiesBatchDefault` is overridden with a smaller value.
##
## Some cursory measurements on `MainNet` suggest an average maximum block
## size ~25KiB (i.e. header + body) at block height ~4.5MiB. There will be
## as many as `nFetchBodiesBatch` blocks on a single staged blocks record.
## And there will be at most `blocksStagedQueueLengthMax+1` records on the
## staged blocks queue. (The `+1` is exceptional, appears when the least
## entry block number is too high and so leaves a gap to the ledger state
## block number.)
# ----------------------
static:
doAssert 0 < runsThisManyPeersOnly
doAssert 0 < nFetchHeadersRequest
doAssert nFetchHeadersRequest <= nFetchHeadersBatch
doAssert 0 < headersStagedQueueLengthLwm
doAssert headersStagedQueueLengthLwm < headersStagedQueueLengthHwm
doAssert 0 < nFetchBodiesRequest
doAssert nFetchBodiesRequest <= nFetchBodiesBatchDefault
doAssert 0 < blocksStagedQueueLenMaxDefault
# End