This is a first step towards measuring the efficiency of the LRU caches
over time - metrics can be collected during import or when running
regulary.
Since `nim-metrics` carries some overhead for its default way of
reporting metrics, this PR implements a custom collector over atomic
counters, given that this is one of the hottest spots in the block
processing pipeline.
Using a compile-time flag, the same metrics can be printed on exit which
is useful when comparing different strategies for caching - here's a
recent run over blocks 16000001-1616384 - this is a good candidate to
expose in a better way in the future, maybe:
```
state vtype miss hit total hitrate
Account Leaf 4909417 4466215 9375632 47.64%
Account Branch 20742574 72015123 92757697 77.64%
World Leaf 940483 1140946 2081429 54.82%
World Branch 8224151 131496580 139720731 94.11%
all all 34816625 209118864 243935489 85.73%
```
* pre-allocate `blobify` data and remove redundant error handling
(cannot fail on correct data)
* use threadvar for temporary storage when decoding rdb, avoiding
closure env
* speed up database walkers by avoiding many temporaries
~5% perf improvement on block import, 100x on database iteration (useful
for building analysis tooling)
Tested up to block ~14m, zstd uses ~12% less space which seems to result
in a small:ish (2-4%) performance improvement on block import speed -
this seems like a better baseline for more extensive testing in the
future.
Pre: 57383308 kb
Post: 50831236 kb
* bump metrics
* Remove cruft
* Cosmetics, update some logging, noise control
* Renamed `CoreDb` function `hasKey` => `hasKeyRc` and provided `hasKey`
why:
Currently, `hasKey` returns a `Result[]` rather than a `bool` which
is what one would expect from a function prototype of this name.
This was a bit of an annoyance and cost unnecessary attention.
In the current VM opcode dispatcher, a two-level case statement is
generated that first matches the opcode and then uses another nested
case statement to select the actual implementation based on which fork
it is, causing the dispatcher to grow by `O(opcodes) * O(forks)`.
The fork does not change between instructions causing significant
inefficiency for this approach - not only because it repeats the fork
lookup but also because of code size bloat and missed optimizations.
A second source of inefficiency in dispatching is the tracer code which
in the vast majority of cases is disabled but nevertheless sees multiple
conditionals being evaluated for each instruction only to remain
disabled throughout exeuction.
This PR rewrites the opcode dispatcher macro to generate a separate
dispatcher for each fork and tracer setting and goes on to pick the
right one at the start of the computation.
This has many advantages:
* much smaller dispatcher
* easier to compile
* better inlining
* fewer pointlessly repeated instruction
* simplified macro (!)
* slow "low-compiler-memory" dispatcher code can be removed
Net block import improvement at about 4-6% depending on the contract -
synthetic EVM benchmnarks would show an even better result most likely.
Because EthBlock is quite large, the stack usage that results from the
multiple copies (temporary and not) present in the import command is
larger than it should be - this PR moves some of that data to a closure
environment allocated once per EthBlock - a larger restructuring of the
code is due but in the meantime, this simple change speeds up garbage
collection a little bit.
* Remove redundant `eth/68` message and clean up docu
details:
There is only eth/68 available at the moment
* Allow to turn on chronicles line number logging in `Makefile`
* Accept (and forget) tx hashes announcements
why:
Does no harm to just ignore it at the moment
* Bump nim-eth (rlp fix)
When the stack has an empty layer on top, there's no need to copy the
contents of `top` to it since it would be the same.
~13% processing saved (!)
pre
```
INF 2024-08-17 19:11:31.748+02:00 Imported blocks
blockNumber=18667648 blocks=12000 importedSlot=7860043 txs=1797812
mgas=181135.177 bps=8.763 tps=1375.062 mgps=132.125 avgBps=6.798
avgTps=1018.501 avgMGps=102.617 elapsed=29m25s154ms
```
post
```
INF 2024-08-17 18:22:52.513+02:00 Imported blocks
blockNumber=18667648 blocks=12000 importedSlot=7860043 txs=1797812
mgas=181135.177 bps=9.648 tps=1513.961 mgps=145.472 avgBps=7.876
avgTps=1179.998 avgMGps=118.888 elapsed=25m23s572ms
```
The reverse slot hash mechanism causes quite a bit of database traffic
but is broadly not useful except for iterating the storage of an
account, something that a validator never does (it's used by the
tracers).
This flag adds one more thing that is not stored in the database, to be
explored more comprehensively when designing full, validator and archive
modes with different pruning options in the future.
`ldb` says this is 60gb of data (!):
```
ldb --db=. --ignore_unknown_options --column_family=KvtGen approxsize
--hex --from=0x05
--to=0x05ffffffffffffffffffffffffffffffffffffffffffffff
66488353954
```
* Move snap un-dumpers to aristo unit test folder
why:
The only place where it is used, now to test the database against
legacy snap sync dump samples.
While the details of the dumped data have mostly outlived their purpuse,
its use as **entropy** data thrown against `Aristo` has still been
useful to find/debug tricky DB problems.
* Remove cruft
* `nimbus-eth1-blobs` not used anymore as test data source
* Cleaning up, removing cruft and debugging statements
* Make `aristo_delta` fluffy compatible
why:
A sub-module that uses `chronicles` must import all possible
modules used by a parent module that imports the sub-module.
* update TODO
* Extract sub-tree deletion functions into separate sub-modules
* Move/rename `aristo_desc.accLruSize` => `aristo_constants.ACC_LRU_SIZE`
* Lazily delete sub-trees
why:
This gives some control of the memory used to keep the deleted vertices
in the cached layers. For larger sub-trees, keys and vertices might be
on the persistent backend to a large extend. This would pull an amount
of extra information from the backend into the cached layer.
For lazy deleting it is enough to remember sub-trees by a small set of
(at most 16) sub-roots to be processed when storing persistent data.
Marking the tree root deleted immediately allows to let most of the code
base work as before.
* Comments and cosmetics
* No need to import all for `Aristo` here
* Kludge to make `chronicle` usage in sub-modules work with `fluffy`
why:
That `fluffy` would not run with any logging in `core_deb` is a problem
I have known for a while. Up to now, logging was only used for debugging.
With the current `Aristo` PR, there are cases where logging might be
wanted but this works only if `chronicles` runs without the
`json[dynamic]` sinks.
So this should be re-visited.
* More of a kludge
why:
It is not safe in general to recycle vertex IDs while the `RocksDb`
cache has `VertexID` rather than `RootedVertexID` where the former
type seems preferable.
In some fringe cases one might remove a vertex with key `(root1,vid)`
and insert another vertex with key `(root2,vid)` while re-using the
vertex ID `vid`. Without knowledge of `root1` and `root2`, the LRU
cache will return the same vertex for `(root2,vid)` also for
`(root1,vid)`.
Based on some simple testing done with a few combinations of cache
sizes, it seems that the block cache has grown in importance compared to
the where we were before changing on-disk format and adding a lot of
other point caches.
With these settings, there's roughly a 15% performance increase when
processing blocks in the 18M range over the status quo while memory
usage decreases by more than 1gb!
Only a few values were tested so there's certainly more to do here but
this change sets up a better baseline for any future optimizations.
In particular, since the initial defaults were chosen root vertex id:s
were introduced as key prefixes meaning that storage for each account
will be grouped together and thus it becomes more likely that a block
loaded from disk will be hit multiple times - this seems to give the
block cache an edge over the row cache, specially when traversing the
storage trie.
* Provide portal proof functions in `aristo_api`
why:
So it can be fully supported by `CoreDb`
* Fix prototype in `kvt_api`
* Fix node constructor for account leafs with storage trees
* Provide simple path check based on portal proof functionality
* Provide portal proof functionality in `CoreDb`
* Update TODO list
* Extracted `test_tx.testTxMergeProofAndKvpList()` => separate file
* Fix serialiser
why:
Typo lead to duplicate rlp-encoded nodes in chain
* Remove cruft
* Implemnt portal proof nodes generators `partXxxTwig()`
* Add unit test for portal proof nodes generator `partAccountTwig()`
* Cosmetics
* Simplify serialiser return code format
* Fix proof generator for extension nodes
why:
Code was simply bonkers, not detected before the unit tests were
adapted to check for just this.
* Implemented portal proof nodes verifier `partUntwig()`
* Cosmetics
* Fix `testutp` cli poblem
* Implement partial trees
why:
This is currently needed for unit tests to pre-load the database
with test data similar to `proof` node pre-load.
The basic features for `snap-sync` boundary proofs are available
as well for future use. What is missing is the final proof verification
and a complete storage data load/merge function (stub is available.)
* Cosmetics, clean up
* remove some redundant EH
* avoid pessimising move (introduces a copy in this case!)
* shift less data around when reading era files (reduces stack usage)
* Update config for Ledger and CoreDb
why:
Prepare for tracer which depends on the API jump table (as well as
the profiler.) The API jump table is now enabled in unit/integration
test mode piggybacking on the `unittest2DisableParamFiltering`
compiler flag or on an extra compiler flag `dbjapi_enabled`.
* No deed for error field in `NodeRef`
why:
Was opnly needed by proof nodes pre-loader which will be re-implemented
* Cosmetics
* Aristo: Merge `delta_siblings` module into `deltaPersistent()`
* Aristo: Add `isEmpty()` for canonical checking whether a layer is empty
* Aristo: Merge `LayerDeltaRef` into `LayerObj`
why:
No need to maintain nested object refs anymore. Previously the
`LayerDeltaRef` object had a companion `LayerFinalRef` which held
non-delta layer information.
* Kvt: Merge `LayerDeltaRef` into `LayerRef`
why:
No need to maintain nested object refs (as with `Aristo`)
* Kvt: Re-write balancer logic similar to `Aristo`
why:
Although `Kvt` was a cheap copy of `Aristo` it sort of got out of
sync and the balancer code was wrong.
* Update iterator over forked peers
why:
Yield additional field `isLast` indicating that the last iteration
cycle was approached.
* Optimise balancer calculation.
why:
One can often avoid providing a new object containing the merge of two
layers for the balancer. This avoids copying tables. In some cases this
is replaced by `hasKey()` look ups though. One uses one of the two
to combine and merges the other into the first.
Of course, this needs some checks for making sure that none of the
components to merge is eventually shared with something else.
* Fix copyright year
When lazily verifying state roots, we may end up with an entire state
without roots that gets computed for the whole database - in the current
design, that would result in hashes for the entire trie being held in
memory.
Since the hash depends only on the data in the vertex, we can store it
directly at the top-most level derived from the verticies it depends on
- be that memory or database - this makes the memory usage broadly
linear with respect to the already-existing in-memory change set stored
in the layers.
It also ensures that if we have multiple forks in memory, hashes get
cached in the correct layer maximising reuse between forks.
The same layer numbering scheme as elsewhere is reused, where -2 is the
backend, -1 is the balancer, then 0+ is the top of the stack and stack.
A downside of this approach is that we create many small batches - a
future improvement could be to collect all such writes in a single
batch, though the memory profile of this approach should be examined
first (where is the batch kept, exactly?).
* Remove `chunkedMpt` from `persistent()`/`stow()` function
why:
Proof-mode code was removed with PR #2445 and needs to be re-designed.
* Remove unused `beStateRoot` argument from `deltaMerge()`
* Update/drastically simplify `txStow()`
why:
Got rid of many boundary conditions
details:
Many pre-conditions have changed. In particular, previous versions
used the account state (hash) which was conveniently available and
checked it against the backend in order to find out whether there
was something to do, at all. Currently, only an empty set of all
tables in the delta layer has the balancer update ignored.
Notable changes are:
* no check against account state (see above)
* balancer filters have no hash signature (some legacy stuff left over
from journals)
* no (shap sync) proof data which made the generation of the a top layer
more complex
* Cosmetics, cruft removal
* Update unit test file & function name
why:
Was legacy module
Our need is only a baseline tx pool gasLimit calculator.
If need we can expand it in the future.
But for now, a simple but understandable tx pool is more important.
* Remove cruft left-over from PR #2494
* TODO
* Update comments on `HashKey` type values
* Remove obsolete hash key conversion flag `forceRoot`
why:
Is treated implicitly by having vertex keys as `HashKey` type and
root vertex states converted to `Hash256`
* Use block number or timestamp to determine fork rules
Avoid confusion raised by `forkGTE` usage where block informations are present.
* Get rid of forkGTE
Jacek Sieka
Jordan Hrycaj
web3-developer
andri lim
Advaita Saha