nimbus-eth1/nimbus/sync/snap/constants.nim

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Nim

# Nimbus
# Copyright (c) 2021 Status Research & Development GmbH
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
# http://www.apache.org/licenses/LICENSE-2.0)
# * MIT license ([LICENSE-MIT](LICENSE-MIT) or
# http://opensource.org/licenses/MIT)
# at your option. This file may not be copied, modified, or distributed
# except according to those terms.
{.push raises: [Defect].}
const
pivotTableLruEntriesMax* = 50
## Max depth of pivot table. On overflow, the oldest one will be removed.
pivotBlockDistanceMin* = 128
## The minimal depth of two block headers needed to activate a new state
## root pivot.
##
## Effects on assembling the state via `snap/1` protocol:
##
## * A small value of this constant increases the propensity to update the
## pivot header more often. This is so because each new peer negoiates a
## pivot block number at least the current one.
##
## * A large value keeps the current pivot more stable but some experiments
## suggest that the `snap/1` protocol is answered only for later block
## numbers (aka pivot blocks.) So a large value tends to keep the pivot
## farther away from the chain head.
##
## Note that 128 is the magic distance for snapshots used by *Geth*.
pivotBlockDistanceThrottledPivotChangeMin* = 256
## Slower pivot change while healing or nearly complete accounts database
## takes place.
pivotEnvStopChangingIfComplete* = true
## If set `true`, new peers will not change the pivot even if the
## negotiated pivot would be newer. This should be the default.
# --------------
snapRequestBytesLimit* = 2 * 1024 * 1024
## Soft bytes limit to request in `snap` protocol calls.
snapRequestTrieNodesFetchMax* = 1024
## Informal maximal number of trie nodes to fetch at once in `snap`
## protocol calls. This is not an official limit but found with several
## implementations (e.g. Geth.)
##
## Resticting the fetch list length early allows to better paralellise
## healing.
snapAccountsSaveProcessedChunksMax* = 1000
## Recovery data are stored if the processed ranges list contains no more
## than this many range *chunks*.
##
## If the range set is too much fragmented, no data will be saved and
## restart has to perform from scratch or an earlier checkpoint.
snapAccountsSaveStorageSlotsMax* = 10_000
## Recovery data are stored if the oustanding storage slots to process do
## not amount to more than this many entries.
##
## If there are too many dangling nodes, no data will be saved and restart
## has to perform from scratch or an earlier checkpoint.
snapStorageSlotsFetchMax* = 2 * 1024
## Maximal number of storage tries to fetch with a single message.
snapStorageSlotsQuPrioThresh* = 5_000
## For a new worker, prioritise processing the storage slots queue over
## processing accounts if the queue has more than this many items.
##
## For a running worker processing accounts, stop processing accounts
## and switch to processing the storage slots queue if the queue has
## more than this many items.
# --------------
swapInAccountsCoverageTrigger* = 0.30
## Similar to `healAccountsCoverageTrigger` below only for trying to
## swap in from earlier pivots.
swapInAccountsPivotsMin* = 2
## Require at least this man pivots available before any swap in can
## take place (must be at least 2.) This value is typically combined
## with `swapInAccountsCoverageTrigger`.
# --------------
healInspectionBatch* = 10_000
## Number of nodes to inspect in a single batch. In between batches, a
## task/thread switch is allowed.
healInspectionBatchWaitNanoSecs* = 500
## Wait some time asynchroneously after processing `healInspectionBatch`
## nodes to allow for a pseudo -task switch.
healAccountsCoverageTrigger* = 0.999
## Apply accounts healing if the global snap download coverage factor
## exceeds this setting. The global coverage factor is derived by merging
## all account ranges retrieved for all pivot state roots (see
## `coveredAccounts` in `CtxData`.)
##
## A small value of this constant leads to early healing. This produces
## stray leaf account records so fragmenting larger intervals of missing
## account ranges. This in turn leads to smaller but more range requests
## over the network. More requests might be a disadvantage if peers only
## serve a maximum number requests (rather than data.)
healAccountsPivotTriggerMinFactor* = 0.17
## Additional condition to meed before starting healing. The current
## pivot must have at least this much processed as recorded in the
## `processed` ranges set. This is the minimim value (see below.)
healAccountsPivotTriggerWeight* = 0.01
healAccountsPivotTriggerNMax* = 10
## Enable healing not before the `processed` ranges set fill factor has
## at least the following value.
## ::
## MinFactor + max(0, NMax - pivotTable.len) * Weight
##
## (the `healAccountsPivotTrigger` prefix of the constant names is ommited.)
##
## This effects in favouring late healing when more pivots have been
## downloaded.
healAccountsBatchFetchMax* = 10 * 1024
## Keep on gloing in healing task up until this many nodes have been
## fetched from the network or some error contition terminates the task.
##
## This constant should be larger than `snapStorageSlotsFetchMax`
healSlorageSlotsTrigger* = 0.70
## Consider per account storage slost healing if a per-account hexary
## sub-trie has reached this factor of completeness.
healStorageSlotsInspectionBatch* = 10_000
## Similar to `healAccountsInspectionBatch` but for storage slots.
healStorageSlotsBatchMax* = 32
## Maximal number of storage tries to to heal in a single batch run. Only
## this many items will be removed from the batch queue. These items will
## then be processed one by one.
# --------------
comErrorsTimeoutMax* = 3
## Maximal number of non-resonses accepted in a row. If there are more than
## `comErrorsTimeoutMax` consecutive errors, the worker will be degraded
## as zombie.
comErrorsTimeoutSleepMSecs* = 5000
## Wait/suspend for this many seconds after a timeout error if there are
## not more than `comErrorsTimeoutMax` errors in a row (maybe some other
## network or no-data errors mixed in.) Set 0 to disable.
comErrorsNetworkMax* = 5
## Similar to `comErrorsTimeoutMax` but for network errors.
comErrorsNetworkSleepMSecs* = 5000
## Similar to `comErrorsTimeoutSleepSecs` but for network errors.
## Set 0 to disable.
comErrorsNoDataMax* = 3
## Similar to `comErrorsTimeoutMax` but for missing data errors.
comErrorsNoDataSleepMSecs* = 0
## Similar to `comErrorsTimeoutSleepSecs` but for missing data errors.
## Set 0 to disable.
static:
doAssert 1 < swapInAccountsPivotsMin
doAssert healAccountsCoverageTrigger < 1.0 # larger values make no sense
doAssert snapStorageSlotsQuPrioThresh < snapAccountsSaveStorageSlotsMax
doAssert snapStorageSlotsFetchMax < healAccountsBatchFetchMax
# ------------------------------------------------------------------------------
# End
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