How to change inflation rate of a substrate based chain?

Question

I want to change inflation rate of a substrate based chain, the method for inflation is written in frame/staking/reward-curve and it being initialised in bin/node/runtime/lib.rs

pallet_staking_reward_curve::build! {
    const REWARD_CURVE: PiecewiseLinear<'static> = curve!(
        min_inflation: 0_025_000,
        max_inflation: 0_100_000,
        ideal_stake: 0_500_000,
        falloff: 0_050_000,
        max_piece_count: 40,
        test_precision: 0_005_000,
    );
}

So i changed the min_inflation and max_inflation in runtime/lib.rs but the inflation rate does change. What I want to ask is am I doing something wrong or is it not the right way to change the inflation rate.

Answer 1

Yes, that's the right way. That's what the pallet wants you to do.

parameter_types! {
    pub const RewardCurve: &'static PiecewiseLinear<'static> = &REWARD_CURVE;
}


impl pallet_staking::Config for Runtime {
    ...
    type EraPayout = pallet_staking::ConvertCurve<RewardCurve>;
}

As you can see, the trait name is Config. So this is a configuration for you.

You may write your pallet in the future. And if you want other people to use the pallet more flexibly. You would also provide some configurations.