Implement RFC #104: Stale Nomination Reward Curve#11961
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shawntabrizi wants to merge 15 commits intomasterfrom
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Implement RFC #104: Stale Nomination Reward Curve#11961shawntabrizi wants to merge 15 commits intomasterfrom
shawntabrizi wants to merge 15 commits intomasterfrom
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Replace the hardcoded 10/10 era constants with a `NominationStalenessCurve` trait wired through `Config`. - `LinearStalenessCurve<GracePeriod, DecayPeriod, Floor>` — piecewise-linear decay, fully configurable. - `NoNominationStaleness` — no-op default that preserves pre-staleness behaviour. - `migrations::nomination_staleness::reset_all_nomination_submitted_in` and try-runtime helpers, ready to be wrapped in a versioned migration when production runtimes opt in. Storage version is intentionally not bumped. The mock runtime defaults the curve to disabled (`grace = u32::MAX`) so existing tests are unaffected. 14 new tests cover the curve at boundaries, refresh-trigger semantics (`nominate` resets, `bond_extra`/`chill` do not), snapshot weight reduction, exclusion at floor 0, and the migration helper. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
shawntabrizi
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shawntabrizi
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May 1, 2026
| /// Intended to be called from inside a versioned `on_runtime_upgrade` when the | ||
| /// nomination-staleness mechanism is first enabled on a runtime. See the module | ||
| /// docs for context. | ||
| pub fn reset_all_nomination_submitted_in<T: Config>() -> Weight { |
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This migration is only needed if we decide to start all nominators as fresh. Maybe an alternative approach would be to hard code a block number which we treat any block before this as starting at that block number.
Some other tricks like this.
kianenigma
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May 4, 2026
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Should be implemented on staking-async pallet, otherwise the structure looks good.
Move `NominationStalenessCurve`, `NoNominationStaleness`, and `LinearStalenessCurve` from `pallet-staking` into `sp-staking` so both `pallet-staking` and `pallet-staking-async` consume the same definitions. Apply the same staleness mechanism to `pallet-staking-async`: - New `Config::NominationStalenessCurve` associated type, defaulting to `NoNominationStaleness` in `TestDefaultConfig`. - Multiplier applied at the snapshot site in `get_npos_voters`. Mirrors the change in `pallet-staking`. - `migrations::nomination_staleness` helpers (`reset_all_nomination_submitted_in` plus try-runtime pre/post helpers), ready to be wrapped in a versioned migration when a runtime opts in. Storage version intentionally not bumped. - Mock wires `LinearStalenessCurve` over mutable `parameter_types!` so individual tests can configure the curve. Defaults disable it (`grace = u32::MAX`). - 14 new tests under `tests::nomination_staleness` mirroring the `pallet-staking` suite. `pallet-staking` and its tests continue to compile and pass (225/225). `pallet-staking-async` tests pass (274/274, +14 from this PR). Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Added the same changes to staking-async (so now both pallets have these changes), and moved the common traits and impls into |
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Qualify links to `NoNominationStaleness` and `reset_all_nomination_submitted_in` so rustdoc can resolve them from their respective scopes (the Config trait doc and the migrations module doc are both outside the scope where the bare names resolve). Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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Description
Implements RFC #104: Stale Nomination Reward Curve.
A nominator's voter weight is multiplied by a configurable decay function based on how long it has been since they last called
nominate. The multiplier is applied at the election snapshot input only; reward distribution downstream is unchanged, so a stale nominator's "lost" share of validator rewards naturally flows to that validator's non-stale co-nominators through existing exposure-based payout math.The mechanism is applied to both
pallet-stakingandpallet-staking-async. The shared trait and default impls live insp-stakingso the two pallets consume the same definitions.What's implemented
sp-stakingNominationStalenessCurvetrait.NoNominationStalenessthat preserves pre-staleness behaviour.LinearStalenessCurve<GracePeriod, DecayPeriod, Floor>.pallet-stakingandpallet-staking-asyncEach pallet adds:
Config::NominationStalenessCurveassociated type.TestDefaultConfigdefaults toNoNominationStaleness.submitted_infield onNominationsis now consumed at the election snapshot site (get_npos_voters) to compute the per-voter multiplier.migrations::nomination_staleness::reset_all_nomination_submitted_inplus try-runtime pre/post helpers, ready to be wrapped in a versioned migration when a runtime opts in. Storage version is intentionally not bumped in this PR.LinearStalenessCurveover mutableparameter_types!. Defaults disable the curve (grace = u32::MAX) so existing tests are unaffected.tests::nomination_staleness:nominateresets even with same targets,bond_extradoes not,chillremoves the entry entirely.Test status
pallet-staking: 225/225 tests pass.pallet-staking-async: 274/274 tests pass (+14 from this PR).sp-staking: compiles clean (including under--all-featuresfortry-runtime).Not in this PR
LinearStalenessCurve<28, 140, 0>into Polkadot / Kusama / Westend runtime configs. Production runtimes should opt in once the RFC is approved.OnRuntimeUpgradewrapper around the migration helpers.pallet-nomination-poolsexercising pool-level freshness.Review focus
NominationStalenessCurveandLinearStalenessCurveinsp-staking.get_npos_voters. These are the single points of behavioural change.28 / 140 / 0); see the RFC's Unresolved Questions for context.