Add branch cache (#2923)

Now that branches are small, we can add a branch cache that fits more
verticies in memory by only storing the branch portion (16 bytes) of the
VertexRef (136 bytes).

Where the original vertex cache hovers around a hit rate of ~60:ish,
this branch cache reaches >90% hit rate instead around block 20M which
gives a nice boost to processing.

A downside of this approach is that a new VertexRef must be allocated
for every cache hit instead of reusing an existing instance - this
causes some GC overhead that needs to be addressed.

Nice 15% improvement nonetheless, can't complain!

```
blocks: 19630784, baseline: 161h18m38s, contender: 136h23m23s
Time (total): -24h55m14s, -15.45%
```
This commit is contained in:
Jacek Sieka 2024-12-11 11:53:26 +01:00 committed by GitHub
parent 29decdf265
commit 7b88bb3b30
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
6 changed files with 140 additions and 49 deletions

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@ -386,17 +386,23 @@ type
defaultValueDesc: $defaultBlockCacheSize
name: "debug-rocksdb-block-cache-size".}: int
rdbVtxCacheSize {.
hidden
defaultValue: defaultRdbVtxCacheSize
defaultValueDesc: $defaultRdbVtxCacheSize
name: "debug-rdb-vtx-cache-size".}: int
rdbKeyCacheSize {.
hidden
defaultValue: defaultRdbKeyCacheSize
defaultValueDesc: $defaultRdbKeyCacheSize
name: "debug-rdb-key-cache-size".}: int
rdbVtxCacheSize {.
rdbBranchCacheSize {.
hidden
defaultValue: defaultRdbVtxCacheSize
defaultValueDesc: $defaultRdbVtxCacheSize
name: "debug-rdb-vtx-cache-size".}: int
defaultValue: defaultRdbBranchCacheSize
defaultValueDesc: $defaultRdbBranchCacheSize
name: "debug-rdb-branch-cache-size".}: int
rdbPrintStats {.
hidden
@ -773,11 +779,13 @@ func dbOptions*(conf: NimbusConf, noKeyCache = false): DbOptions =
rowCacheSize = conf.rocksdbRowCacheSize,
blockCacheSize = conf.rocksdbBlockCacheSize,
rdbKeyCacheSize =
if noKeyCache: 0 else: conf.rdbKeyCacheSize ,
rdbVtxCacheSize =
# The import command does not use the key cache - better give it to vtx
if noKeyCache: conf.rdbKeyCacheSize + conf.rdbVtxCacheSize
else: conf.rdbVtxCacheSize,
if noKeyCache: 0 else: conf.rdbKeyCacheSize,
rdbVtxCacheSize = conf.rdbVtxCacheSize,
rdbBranchCacheSize =
# The import command does not use the key cache - better give it to branch
if noKeyCache: conf.rdbKeyCacheSize + conf.rdbBranchCacheSize
else: conf.rdbBranchCacheSize,
rdbPrintStats = conf.rdbPrintStats,
)

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@ -60,6 +60,9 @@ type
rdVtxLru*: LruCache[VertexID,VertexRef] ## Read cache
rdVtxSize*: int
rdBranchLru*: LruCache[VertexID, (VertexID, uint16)]
rdBranchSize*: int
basePath*: string ## Database directory
trgWriteEvent*: RdbWriteEventCb ## Database piggiback call back handler
@ -84,6 +87,7 @@ var
# happens from a separate thread.
# TODO maybe turn this into more general framework for LRU reporting since
# we have lots of caches of this sort
rdbBranchLruStats*: array[RdbStateType, RdbLruCounter]
rdbVtxLruStats*: array[RdbStateType, array[VertexType, RdbLruCounter]]
rdbKeyLruStats*: array[RdbStateType, RdbLruCounter]

View File

@ -36,6 +36,7 @@ when defined(metrics):
type
RdbVtxLruCounter = ref object of Counter
RdbKeyLruCounter = ref object of Counter
RdbBranchLruCounter = ref object of Counter
var
rdbVtxLruStatsMetric {.used.} = RdbVtxLruCounter.newCollector(
@ -46,6 +47,9 @@ when defined(metrics):
rdbKeyLruStatsMetric {.used.} = RdbKeyLruCounter.newCollector(
"aristo_rdb_key_lru_total", "HashKey LRU lookup", labels = ["state", "hit"]
)
rdbBranchLruStatsMetric {.used.} = RdbBranchLruCounter.newCollector(
"aristo_rdb_branch_lru_total", "Branch LRU lookup", labels = ["state", "hit"]
)
method collect*(collector: RdbVtxLruCounter, output: MetricHandler) =
let timestamp = collector.now()
@ -76,6 +80,19 @@ when defined(metrics):
timestamp = timestamp,
)
method collect*(collector: RdbBranchLruCounter, output: MetricHandler) =
let timestamp = collector.now()
for state in RdbStateType:
for hit in [false, true]:
output(
name = "aristo_rdb_branch_lru_total",
value = float64(rdbBranchLruStats[state].get(hit)),
labels = ["state", "hit"],
labelValues = [$state, $ord(hit)],
timestamp = timestamp,
)
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
@ -156,6 +173,17 @@ proc getVtx*(
rdb: var RdbInst, rvid: RootedVertexID, flags: set[GetVtxFlag]
): Result[VertexRef, (AristoError, string)] =
# Try LRU cache first
block:
let rc =
if GetVtxFlag.PeekCache in flags:
rdb.rdBranchLru.peek(rvid.vid)
else:
rdb.rdBranchLru.get(rvid.vid)
if rc.isOk():
rdbBranchLruStats[rvid.to(RdbStateType)].inc(true)
return ok(VertexRef(vType: Branch, startVid: rc[][0], used: rc[][1]))
block:
var rc =
if GetVtxFlag.PeekCache in flags:
rdb.rdVtxLru.peek(rvid.vid)
@ -186,10 +214,16 @@ proc getVtx*(
if res.isErr():
return err((res.error(), "Parsing failed")) # Parsing failed
if res.value.vType == Branch and res.value.pfx.len == 0:
rdbBranchLruStats[rvid.to(RdbStateType)].inc(false)
else:
rdbVtxLruStats[rvid.to(RdbStateType)][res.value().vType].inc(false)
# Update cache and return - in peek mode, avoid evicting cache items
if GetVtxFlag.PeekCache notin flags or rdb.rdVtxLru.len < rdb.rdVtxLru.capacity:
if GetVtxFlag.PeekCache notin flags:
if res.value.vType == Branch and res.value.pfx.len == 0:
rdb.rdBranchLru.put(rvid.vid, (res.value().startVid, res.value.used))
else:
rdb.rdVtxLru.put(rvid.vid, res.value())
ok res.value()

View File

@ -25,11 +25,9 @@ import
# Private constructor
# ------------------------------------------------------------------------------
const
lruOverhead = 20
# Approximate LRU cache overhead per entry based on minilru sizes
const lruOverhead = 20 # Approximate LRU cache overhead per entry based on minilru sizes
proc dumpCacheStats(keySize, vtxSize: int) =
proc dumpCacheStats(keySize, vtxSize, branchSize: int) =
block vtx:
var misses, hits: uint64
echo "vtxLru(", vtxSize, ")"
@ -67,14 +65,33 @@ proc dumpCacheStats(keySize, vtxSize: int) =
let hitRate = float64(hits * 100) / (float64(hits + misses))
echo &" all {misses:>10} {hits:>10} {misses+hits:>10} {hitRate:>5.2f}%"
block key:
var misses, hits: uint64
echo "branchLru(", branchSize, ") "
echo " state miss hit total hitrate"
for state in RdbStateType:
let
(miss, hit) =
(rdbBranchLruStats[state].get(false), rdbBranchLruStats[state].get(true))
hitRate = float64(hit * 100) / (float64(hit + miss))
misses += miss
hits += hit
echo &"{state:>8} {miss:>10} {hit:>10} {miss+hit:>10} {hitRate:>5.2f}%"
let hitRate = float64(hits * 100) / (float64(hits + misses))
echo &" all {misses:>10} {hits:>10} {misses+hits:>10} {hitRate:>5.2f}%"
proc initImpl(
rdb: var RdbInst;
basePath: string;
opts: DbOptions;
rdb: var RdbInst,
basePath: string,
opts: DbOptions,
dbOpts: DbOptionsRef,
cfOpts: ColFamilyOptionsRef;
guestCFs: openArray[ColFamilyDescriptor] = [];
): Result[seq[ColFamilyReadWrite],(AristoError,string)] =
cfOpts: ColFamilyOptionsRef,
guestCFs: openArray[ColFamilyDescriptor] = [],
): Result[seq[ColFamilyReadWrite], (AristoError, string)] =
## Database backend constructor
const initFailed = "RocksDB/init() failed"
@ -84,23 +101,30 @@ proc initImpl(
rdb.rdKeySize =
opts.rdbKeyCacheSize div (sizeof(VertexID) + sizeof(HashKey) + lruOverhead)
rdb.rdVtxSize =
opts.rdbVtxCacheSize div (sizeof(VertexID) + sizeof(default(VertexRef)[]) + lruOverhead)
opts.rdbVtxCacheSize div
(sizeof(VertexID) + sizeof(default(VertexRef)[]) + lruOverhead)
rdb.rdBranchSize =
opts.rdbBranchCacheSize div (sizeof(typeof(rdb.rdBranchLru).V) + lruOverhead)
rdb.rdKeyLru = typeof(rdb.rdKeyLru).init(rdb.rdKeySize)
rdb.rdVtxLru = typeof(rdb.rdVtxLru).init(rdb.rdVtxSize)
rdb.rdBranchLru = typeof(rdb.rdBranchLru).init(rdb.rdBranchSize)
if opts.rdbPrintStats:
let
ks = rdb.rdKeySize
vs = rdb.rdVtxSize
bs = rdb.rdBranchSize
# TODO instead of dumping at exit, these stats could be logged or written
# to a file for better tracking over time - that said, this is mainly
# a debug utility at this point
addExitProc(proc() =
dumpCacheStats(ks, vs))
addExitProc(
proc() =
dumpCacheStats(ks, vs, bs)
)
let
dataDir = rdb.dataDir
let dataDir = rdb.dataDir
try:
dataDir.createDir
except OSError, IOError:
@ -132,7 +156,7 @@ proc initImpl(
let cfs = useCFs.toSeq.mapIt(it.initColFamilyDescriptor cfOpts) & guestCFq
# Open database for the extended family :)
let baseDb = openRocksDb(dataDir, dbOpts, columnFamilies=cfs).valueOr:
let baseDb = openRocksDb(dataDir, dbOpts, columnFamilies = cfs).valueOr:
raiseAssert initFailed & " cannot create base descriptor: " & error
# Initialise column handlers (this stores implicitely `baseDb`)
@ -148,18 +172,17 @@ proc initImpl(
# ------------------------------------------------------------------------------
proc init*(
rdb: var RdbInst;
basePath: string;
opts: DbOptions;
dbOpts: DbOptionsRef;
cfOpts: ColFamilyOptionsRef;
guestCFs: openArray[ColFamilyDescriptor];
): Result[seq[ColFamilyReadWrite],(AristoError,string)] =
rdb: var RdbInst,
basePath: string,
opts: DbOptions,
dbOpts: DbOptionsRef,
cfOpts: ColFamilyOptionsRef,
guestCFs: openArray[ColFamilyDescriptor],
): Result[seq[ColFamilyReadWrite], (AristoError, string)] =
## Temporarily define a guest CF list here.
rdb.initImpl(basePath, opts, dbOpts, cfOpts, guestCFs)
proc destroy*(rdb: var RdbInst; eradicate: bool) =
proc destroy*(rdb: var RdbInst, eradicate: bool) =
## Destructor
rdb.baseDb.close()
@ -174,7 +197,6 @@ proc destroy*(rdb: var RdbInst; eradicate: bool) =
if 0 < w.len and w[^1] != '~':
break done
rdb.baseDir.removeDir
except CatchableError:
discard

View File

@ -51,6 +51,7 @@ proc rollback*(rdb: var RdbInst) =
if not rdb.session.isClosed():
rdb.rdKeyLru = typeof(rdb.rdKeyLru).init(rdb.rdKeySize)
rdb.rdVtxLru = typeof(rdb.rdVtxLru).init(rdb.rdVtxSize)
rdb.rdBranchLru = typeof(rdb.rdBranchLru).init(rdb.rdBranchSize)
rdb.disposeSession()
proc commit*(rdb: var RdbInst): Result[void,(AristoError,string)] =
@ -100,8 +101,24 @@ proc putVtx*(
# Update existing cached items but don't add new ones since doing so is
# likely to evict more useful items (when putting many items, we might even
# evict those that were just added)
if vtx.vType == Branch and vtx.pfx.len == 0:
rdb.rdVtxLru.del(rvid.vid)
if rdb.rdBranchLru.len < rdb.rdBranchLru.capacity:
rdb.rdBranchLru.put(rvid.vid, (vtx.startVid, vtx.used))
else:
discard rdb.rdBranchLru.update(rvid.vid, (vtx.startVid, vtx.used))
else:
rdb.rdBranchLru.del(rvid.vid)
if rdb.rdVtxLru.len < rdb.rdVtxLru.capacity:
rdb.rdVtxLru.put(rvid.vid, vtx)
else:
discard rdb.rdVtxLru.update(rvid.vid, vtx)
if key.isValid:
if rdb.rdKeyLru.len < rdb.rdKeyLru.capacity:
rdb.rdKeyLru.put(rvid.vid, key)
else:
discard rdb.rdKeyLru.update(rvid.vid, key)
else:
rdb.rdKeyLru.del rvid.vid
@ -115,6 +132,7 @@ proc putVtx*(
return err((rvid.vid,errSym,error))
# Update cache, vertex will most probably never be visited anymore
rdb.rdBranchLru.del rvid.vid
rdb.rdVtxLru.del rvid.vid
rdb.rdKeyLru.del rvid.vid

View File

@ -33,10 +33,12 @@ const
## re-reads from file.
##
## A bit of space on top of the filter is left for data block caching
defaultRdbVtxCacheSize* = 768 * 1024 * 1024
defaultRdbVtxCacheSize* = 512 * 1024 * 1024
## Cache of branches and leaves in the state MPTs (world and account)
defaultRdbKeyCacheSize* = 256 * 1024 * 1024
## Hashes of the above
defaultRdbBranchCacheSize* = 1024 * 1024 * 1024
## Cache of branches and leaves in the state MPTs (world and account)
type DbOptions* = object # Options that are transported to the database layer
@ -46,6 +48,7 @@ type DbOptions* = object # Options that are transported to the database layer
blockCacheSize*: int
rdbVtxCacheSize*: int
rdbKeyCacheSize*: int
rdbBranchCacheSize*: int
rdbPrintStats*: bool
func init*(
@ -56,6 +59,7 @@ func init*(
blockCacheSize = defaultBlockCacheSize,
rdbVtxCacheSize = defaultRdbVtxCacheSize,
rdbKeyCacheSize = defaultRdbKeyCacheSize,
rdbBranchCacheSize = defaultRdbBranchCacheSize,
rdbPrintStats = false,
): T =
T(
@ -65,5 +69,6 @@ func init*(
blockCacheSize: blockCacheSize,
rdbVtxCacheSize: rdbVtxCacheSize,
rdbKeyCacheSize: rdbKeyCacheSize,
rdbBranchCacheSize: rdbBranchCacheSize,
rdbPrintStats: rdbPrintStats,
)