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bug: fix algorithm overflow issues #2173

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merged 34 commits into from
Sep 11, 2024
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@MitchTurner MitchTurner commented Sep 6, 2024

Linked Issues/PRs

Closes #2164
Closes #2147

Description

The main change with this code is "normalizaing" the costs and rewards instead of keeping a total over all time. i.e. every time we receive a DA block, we see if the reward is greater than the costs, or vice versa. If the reward is higher, we set the reward to the difference and set the the last known cost to 0 and adjust the projected cost accordingly.

In addition, we were using a random set of types for the algorithm and also used casts in many places. This PR should fix a lot of those problems.

Bonus: This fix prompted me to run the optimization again. Since the set is much bigger now, I decided to enable running the simulation in parallel tasks to speed up the code.

Checklist

  • New behavior is reflected in tests

Before requesting review

  • I have reviewed the code myself

@MitchTurner MitchTurner self-assigned this Sep 10, 2024
@MitchTurner MitchTurner added the no changelog Skip the CI check of the changelog modification label Sep 10, 2024
@MitchTurner MitchTurner changed the title Bug/fix algorithm giving up 2164 bug: fix algorithm overflow issues Sep 10, 2024
@MitchTurner MitchTurner marked this pull request as ready for review September 10, 2024 15:41
@MitchTurner MitchTurner requested a review from a team September 10, 2024 15:41
Comment on lines 67 to 69
da_p_factor: i64,
/// The D component of the PID control for the DA gas price
da_d_factor: i64,
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is my understanding correct that these values are i64's because we need them to be for float calculation?

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I'm not sure what you mean by "float calculation". We don't have any floats in this code.

These actually probably don't need to be i and could be u. When I added them originally, I was open to the idea of using negative values. Just haven't reevaluated.

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ah okay. as far as i remember there were a bunch of floats used so i might be wrong

@@ -283,3 +290,127 @@ fn update__da_block_updates_projected_total_cost_with_known_and_guesses_on_top()
let expected = new_known_total_cost + guessed_part;
assert_eq!(actual, expected as u128);
}

prop_compose! {
fn arb_vec_of_da_blocks()(last_da_block: u32, count in 1..255usize, rng_seed: u64) -> Vec<RecordedBlock> {
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Maybe should use a different value than 255. That makes it seem non-arbitrary.

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@Dentosal Dentosal Sep 10, 2024

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I often use numbers like 123, 1234 or 0x1234, if there's no good reason to do otherwise. They contain no secondary meaning unlike 100 or 255, and are good nothing-up-my-sleeve numbers

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LGTM in general, left some suggestions/questions

crates/fuel-gas-price-algorithm/src/v1.rs Outdated Show resolved Hide resolved
@@ -153,11 +161,11 @@ pub struct AlgorithmUpdaterV1 {
/// The maximum percentage that the DA portion of the gas price can change in a single block
pub max_da_gas_price_change_percent: u8,
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@Dentosal Dentosal Sep 10, 2024

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nit: I feel like introducing a newtype to enforce the percentage invariant (in range 0..=100, or even nonzero here) might be a good idea. Up to you.

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I'm open to it! I'd just have to introduce fallibility into the constructor.

Also. In theory, this could be set to something larger than 100%. So even u8 is an arbitrary ceiling to how high it could be set to. I'm realizing that's why exec_gas_price_change_percent wasn't u8 before. Both could be higher in theory.

The l2_block_fullness_threshold_percent on the otherhand would be a better candidate for a newtype since there is no such thing as a 110% full block hopefully.

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@Dentosal Dentosal Sep 10, 2024

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The arbitrary u8 ceiling feels weird, if there's ever any reason to set it to 200%, surely there are also reasons to set it to 300% as well? In any case, it wasn't clear to me from the doc comment, so maybe explicitly writing it there would be a good first step, and the newtype can be introduced later when the implementation has settled down.

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@MitchTurner MitchTurner Sep 10, 2024

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Changed both to u16 and added explanation in comments. Will look into newtype.

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Added a newtype for the threshold percentage. I called it ClampedPercent to communicate that it's infallible and just clamps the value.

Dentosal
Dentosal previously approved these changes Sep 10, 2024
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LGTM; although I was mostly looking at the changeset and not the whole picture

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I hope @rymnc tried to dive deeper in the formulas and checked them=D

plotters = "0.3.5"
rand = "0.8.5"
rand_distr = "0.4.3"
serde = { version = "1.0.209", features = ["derive"] }
tokio = { version = "1.40.0", features = ["full"] }
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It is better to not use full if you only need something specific=)

@@ -25,6 +25,7 @@ pub fn get_da_cost_per_byte_from_source(
}
}

#[allow(dead_code)]
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Where do we use it?

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It's used in CSV reader.

@MitchTurner MitchTurner merged commit f308bae into master Sep 11, 2024
35 checks passed
@MitchTurner MitchTurner deleted the bug/fix-algorithm-giving-up-2164 branch September 11, 2024 08:53
@xgreenx xgreenx mentioned this pull request Sep 17, 2024
xgreenx added a commit that referenced this pull request Sep 18, 2024
## Version v0.36.0

### Added
- [2135](#2135): Added metrics
logging for number of blocks served over the p2p req/res protocol.
- [2151](#2151): Added
limitations on gas used during dry_run in API.
- [2188](#2188): Added the new
variant `V2` for the `ConsensusParameters` which contains the new
`block_transaction_size_limit` parameter.
- [2163](#2163): Added
runnable task for fetching block committer data.
- [2204](#2204): Added
`dnsaddr` resolution for TLD without suffixes.

### Changed

#### Breaking
- [2199](#2199): Applying
several breaking changes to the WASM interface from backlog:
- Get the module to execute WASM byte code from the storage first, an
fallback to the built-in version in the case of the
`FUEL_ALWAYS_USE_WASM`.
- Added `host_v1` with a new `peek_next_txs_size` method, that accepts
`tx_number_limit` and `size_limit`.
- Added new variant of the return type to pass the validation result. It
removes block serialization and deserialization and should improve
performance.
- Added a V1 execution result type that uses `JSONError` instead of
postcard serialized error. It adds flexibility of how variants of the
error can be managed. More information about it in
FuelLabs/fuel-vm#797. The change also moves
`TooManyOutputs` error to the top. It shows that `JSONError` works as
expected.
- [2145](#2145): feat:
Introduce time port in PoA service.
- [2155](#2155): Added trait
declaration for block committer data
- [2142](#2142): Added
benchmarks for varied forms of db lookups to assist in optimizations.
- [2158](#2158): Log the
public address of the signing key, if it is specified
- [2188](#2188): Upgraded the
`fuel-vm` to `0.57.0`. More information in the
[release](https://github.com/FuelLabs/fuel-vm/releases/tag/v0.57.0).

## What's Changed
* chore(p2p_service): add metrics for number of blocks requested over
p2p req/res protocol by @rymnc in
#2135
* Weekly `cargo update` by @github-actions in
#2149
* Debug V1 algorightm and use more realistic values in gas price
analysis by @MitchTurner in
#2129
* feat(gas_price_service): include trait declaration for block committer
data by @rymnc in #2155
* Convert gas price analysis tool to CLI by @MitchTurner in
#2156
* chore: add benchmarks for varied forms of lookups by @rymnc in
#2142
* Add label nochangelog on weekly cargo update by @AurelienFT in
#2152
* Log consensus-key signer address if specified by @acerone85 in
#2158
* chore(rocks_db): move ShallowTempDir to benches crate by @rymnc in
#2168
* chore(benches): conditional dropping of databases in benchmarks by
@rymnc in #2170
* feat: Introduce time port in PoA service by @netrome in
#2145
* Get DA costs from predefined data by @MitchTurner in
#2157
* chore(shallow_temp_dir): panic if not panicking by @rymnc in
#2172
* chore: Add initial CODEOWNERS file by @netrome in
#2179
* Weekly `cargo update` by @github-actions in
#2177
* fix(db_lookup_times): rework core logic of benchmark by @rymnc in
#2159
* Add verification on transaction dry_run that they don't spend more
than block gas limit by @AurelienFT in
#2151
* bug: fix algorithm overflow issues by @MitchTurner in
#2173
* feat(gas_price_service): create runnable task for expensive background
polling for da metadata by @rymnc in
#2163
* Weekly `cargo update` by @github-actions in
#2197
* Fix bug with gas price factor in V1 algorithm by @MitchTurner in
#2201
* Applying several breaking changes to the WASM interface from backlog
by @xgreenx in #2199
* chore(p2p): dnsaddr recursive resolution by @rymnc in
#2204

## New Contributors
* @acerone85 made their first contribution in
#2158

**Full Changelog**:
v0.35.0...v0.36.0
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