Jacek Sieka 01ca415721
Store keys together with node data (#2849)
Currently, computed hash keys are stored in a separate column family
with respect to the MPT data they're generated from - this has several
disadvantages:

* A lot of space is wasted because the lookup key (`RootedVertexID`) is
repeated in both tables - this is 30% of the `AriKey` content!
* rocksdb must maintain in-memory bloom filters and LRU caches for said
keys, doubling its "minimal efficient cache size"
* An extra disk traversal must be made to check for existence of cached
hash key
* Doubles the amount of files on disk due to each column family being
its own set of files

Here, the two CFs are joined such that both key and data is stored in
`AriVtx`. This means:

* we save ~30% disk space on repeated lookup keys
* we save ~2gb of memory overhead that can be used to cache data instead
of indices
* we can skip storing hash keys for MPT leaf nodes - these are trivial
to compute and waste a lot of space - previously they had to present in
the `AriKey` CF to avoid having to look in two tables on the happy path.
* There is a small increase in write amplification because when a hash
value is updated for a branch node, we must write both key and branch
data - previously we would write only the key
* There's a small shift in CPU usage - instead of performing lookups in
the database, hashes for leaf nodes are (re)-computed on the fly
* We can return to slightly smaller on-disk SST files since there's
fewer of them, which should reduce disk traffic a bit

Internally, there are also other advantages:

* when clearing keys, we no longer have to store a zero hash in memory -
instead, we deduce staleness of the cached key from the presence of an
updated VertexRef - this saves ~1gb of mem overhead during import
* hash key cache becomes dedicated to branch keys since leaf keys are no
longer stored in memory, reducing churn
* key computation is a lot faster thanks to the skipped second disk
traversal - a key computation for mainnet can be completed in 11 hours
instead of ~2 days (!) thanks to better cache usage and less read
amplification - with additional improvements to the on-disk format, we
can probably get rid of the initial full traversal method of seeding the
key cache on first start after import

All in all, this PR reduces the size of a mainnet database from 160gb to
110gb and the peak memory footprint during import by ~1-2gb.
2024-11-20 09:56:27 +01:00

315 lines
9.2 KiB
Nim

# nimbus-eth1
# Copyright (c) 2023-2024 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.
## Rocksdb backend for Aristo DB
## =============================
##
## The iterators provided here are currently available only by direct
## backend access
## ::
## import
## aristo/aristo_init,
## aristo/aristo_init/aristo_rocksdb
##
## let rc = AristoDb.init(BackendRocksDB, "/var/tmp")
## if rc.isOk:
## let be = rc.value.to(RdbBackendRef)
## for (n, key, vtx) in be.walkVtx:
## ...
##
{.push raises: [].}
import
eth/common,
rocksdb,
results,
../aristo_desc,
../aristo_desc/desc_backend,
../aristo_blobify,
./init_common,
./rocks_db/[rdb_desc, rdb_get, rdb_init, rdb_put, rdb_walk],
../../opts
const
extraTraceMessages = false
## Enabled additional logging noise
type
RdbBackendRef* = ref object of TypedBackendRef
rdb: RdbInst ## Allows low level access to database
RdbPutHdlRef = ref object of TypedPutHdlRef
when extraTraceMessages:
import chronicles
logScope:
topics = "aristo-backend"
# ------------------------------------------------------------------------------
# Private helpers
# ------------------------------------------------------------------------------
proc newSession(db: RdbBackendRef): RdbPutHdlRef =
new result
result.TypedPutHdlRef.beginSession db
proc getSession(hdl: PutHdlRef; db: RdbBackendRef): RdbPutHdlRef =
hdl.TypedPutHdlRef.verifySession db
hdl.RdbPutHdlRef
proc endSession(hdl: PutHdlRef; db: RdbBackendRef): RdbPutHdlRef =
hdl.TypedPutHdlRef.finishSession db
hdl.RdbPutHdlRef
# ------------------------------------------------------------------------------
# Private functions: interface
# ------------------------------------------------------------------------------
proc getVtxFn(db: RdbBackendRef): GetVtxFn =
result =
proc(rvid: RootedVertexID, flags: set[GetVtxFlag]): Result[VertexRef,AristoError] =
# Fetch serialised data record
let vtx = db.rdb.getVtx(rvid, flags).valueOr:
when extraTraceMessages:
trace logTxt "getVtxFn() failed", rvid, error=error[0], info=error[1]
return err(error[0])
if vtx.isValid:
return ok(vtx)
err(GetVtxNotFound)
proc getKeyFn(db: RdbBackendRef): GetKeyFn =
result =
proc(rvid: RootedVertexID): Result[HashKey,AristoError] =
# Fetch serialised data record
let key = db.rdb.getKey(rvid).valueOr:
when extraTraceMessages:
trace logTxt "getKeyFn: failed", rvid, error=error[0], info=error[1]
return err(error[0])
if key.isValid:
return ok(key)
err(GetKeyNotFound)
proc getTuvFn(db: RdbBackendRef): GetTuvFn =
result =
proc(): Result[VertexID,AristoError]=
# Fetch serialised data record.
let data = db.rdb.getAdm(AdmTabIdTuv).valueOr:
when extraTraceMessages:
trace logTxt "getTuvFn: failed", error=error[0], info=error[1]
return err(error[0])
# Decode data record
if data.len == 0:
return ok VertexID(0)
# Decode data record
result = data.deblobify VertexID
proc getLstFn(db: RdbBackendRef): GetLstFn =
result =
proc(): Result[SavedState,AristoError]=
# Fetch serialised data record.
let data = db.rdb.getAdm(AdmTabIdLst).valueOr:
when extraTraceMessages:
trace logTxt "getLstFn: failed", error=error[0], info=error[1]
return err(error[0])
# Decode data record
data.deblobify SavedState
# -------------
proc putBegFn(db: RdbBackendRef): PutBegFn =
result =
proc(): Result[PutHdlRef,AristoError] =
db.rdb.begin()
ok db.newSession()
proc putVtxFn(db: RdbBackendRef): PutVtxFn =
result =
proc(hdl: PutHdlRef; rvid: RootedVertexID; vtx: VertexRef, key: HashKey) =
let hdl = hdl.getSession db
if hdl.error.isNil:
db.rdb.putVtx(rvid, vtx, key).isOkOr:
hdl.error = TypedPutHdlErrRef(
pfx: VtxPfx,
vid: error[0],
code: error[1],
info: error[2])
proc putTuvFn(db: RdbBackendRef): PutTuvFn =
result =
proc(hdl: PutHdlRef; vs: VertexID) =
let hdl = hdl.getSession db
if hdl.error.isNil:
if vs.isValid:
db.rdb.putAdm(AdmTabIdTuv, vs.blobify.data()).isOkOr:
hdl.error = TypedPutHdlErrRef(
pfx: AdmPfx,
aid: AdmTabIdTuv,
code: error[1],
info: error[2])
return
proc putLstFn(db: RdbBackendRef): PutLstFn =
result =
proc(hdl: PutHdlRef; lst: SavedState) =
let hdl = hdl.getSession db
if hdl.error.isNil:
let data = lst.blobify.valueOr:
hdl.error = TypedPutHdlErrRef(
pfx: AdmPfx,
aid: AdmTabIdLst,
code: error)
return
db.rdb.putAdm(AdmTabIdLst, data).isOkOr:
hdl.error = TypedPutHdlErrRef(
pfx: AdmPfx,
aid: AdmTabIdLst,
code: error[1],
info: error[2])
proc putEndFn(db: RdbBackendRef): PutEndFn =
result =
proc(hdl: PutHdlRef): Result[void,AristoError] =
let hdl = hdl.endSession db
if not hdl.error.isNil:
when extraTraceMessages:
case hdl.error.pfx:
of VtxPfx, KeyPfx: trace logTxt "putEndFn: vtx/key failed",
pfx=hdl.error.pfx, vid=hdl.error.vid, error=hdl.error.code
of AdmPfx: trace logTxt "putEndFn: admin failed",
pfx=AdmPfx, aid=hdl.error.aid.uint64, error=hdl.error.code
of Oops: trace logTxt "putEndFn: oops",
pfx=hdl.error.pfx, error=hdl.error.code
db.rdb.rollback()
return err(hdl.error.code)
# Commit session
db.rdb.commit().isOkOr:
when extraTraceMessages:
trace logTxt "putEndFn: failed", error=($error[0]), info=error[1]
return err(error[0])
ok()
proc closeFn(db: RdbBackendRef): CloseFn =
result =
proc(eradicate: bool) =
db.rdb.destroy(eradicate)
# ------------------------------------------------------------------------------
# Private functions: hosting interface changes
# ------------------------------------------------------------------------------
proc putBegHostingFn(db: RdbBackendRef): PutBegFn =
result =
proc(): Result[PutHdlRef,AristoError] =
db.rdb.begin()
if db.rdb.trgWriteEvent(db.rdb.session):
ok db.newSession()
else:
when extraTraceMessages:
trace logTxt "putBegFn: guest trigger aborted session"
db.rdb.rollback()
err(RdbGuestInstanceAborted)
# ------------------------------------------------------------------------------
# Public functions
# ------------------------------------------------------------------------------
proc rocksDbBackend*(
path: string;
opts: DbOptions;
dbOpts: DbOptionsRef;
cfOpts: ColFamilyOptionsRef;
guestCFs: openArray[ColFamilyDescriptor];
): Result[(BackendRef, seq[ColFamilyReadWrite]),AristoError] =
let db = RdbBackendRef(
beKind: BackendRocksDB)
# Initialise RocksDB
let oCfs = block:
let rc = db.rdb.init(path, opts, dbOpts, cfOpts, guestCFs)
if rc.isErr:
when extraTraceMessages:
trace logTxt "constructor failed",
error=rc.error[0], info=rc.error[1]
return err(rc.error[0])
rc.value()
db.getVtxFn = getVtxFn db
db.getKeyFn = getKeyFn db
db.getTuvFn = getTuvFn db
db.getLstFn = getLstFn db
db.putBegFn = putBegFn db
db.putVtxFn = putVtxFn db
db.putTuvFn = putTuvFn db
db.putLstFn = putLstFn db
db.putEndFn = putEndFn db
db.closeFn = closeFn db
ok((db, oCfs))
proc rocksDbSetEventTrigger*(
be: BackendRef;
hdl: RdbWriteEventCb;
): Result[void,AristoError] =
## Store event trigger. This also changes the backend type.
if hdl.isNil:
err(RdbBeWrTriggerNilFn)
else:
let db = RdbBackendRef(be)
db.rdb.trgWriteEvent = hdl
db.beKind = BackendRdbHosting
db.putBegFn = putBegHostingFn db
ok()
proc dup*(db: RdbBackendRef): RdbBackendRef =
## Duplicate descriptor shell as needed for API debugging
new result
init_common.init(result[], db[])
result.rdb = db.rdb
# ------------------------------------------------------------------------------
# Public iterators (needs direct backend access)
# ------------------------------------------------------------------------------
iterator walkVtx*(
be: RdbBackendRef;
kinds = {Branch, Leaf};
): tuple[evid: RootedVertexID, vtx: VertexRef] =
## Variant of `walk()` iteration over the vertex sub-table.
for (rvid, vtx) in be.rdb.walkVtx(kinds):
yield (rvid, vtx)
iterator walkKey*(
be: RdbBackendRef;
): tuple[rvid: RootedVertexID, key: HashKey] =
## Variant of `walk()` iteration over the Markle hash sub-table.
for (rvid, data) in be.rdb.walkKey:
yield (rvid, data)
# ------------------------------------------------------------------------------
# End
# ------------------------------------------------------------------------------