# Distribution
TIP
Paloma's distribution module inherits from Cosmos SDK's distribution
(opens new window) module. This document is a stub and covers mainly important Paloma-specific notes about how it is used.
The distribution module describes a mechanism that tracks collected fees and passively distributes them to validators and delegators. Additionally, the distribution module defines the community pool, which is a pool of funds under the control of on-chain governance.
# Concepts
# Validator and delegator rewards
TIP
Passive distribution means that validators and delegators need to manually collect their fee rewards by submitting withdrawal transactions.
Collected rewards are pooled globally and distrubuted to validators and delegators. Each validator has the opportunity to charge delegators commission on the rewards collected on behalf of the delegators. Fees are collected directly into a global reward pool and a validator proposer-reward pool. Due to the nature of passive accounting, whenever changes to parameters which affect the rate of reward distribution occur, withdrawal of rewards must also occur.
# State
This section was taken from the official Cosmos SDK docs, and placed here for your convenience to understand the distribution module's parameters and genesis variables.
# FeePool
All globally tracked parameters for distribution are stored within
FeePool
. Rewards are collected and added to the reward pool and
distributed to validators/delegators from here.
Note that the reward pool holds decimal coins (DecCoins
) to allow
for fractions of coins to be received from operations like inflation.
When coins are distributed from the pool they are truncated back to
sdk.Coins
which are non-decimal.
# Validator distribution
The following validator distribution information for the relevant validator is updated each time:
- Delegation amount to a validator is updated,
- A validator successfully proposes a block and receives a reward.
- Any delegator withdraws from a validator or the validator withdraws its commission.
# Delegation distribution
Each delegation distribution only needs to record the height at which it last withdrew fees. Because a delegation must withdraw fees each time its properties change (aka bonded tokens etc.), its properties will remain constant and the delegator's accumulation factor can be calculated passively knowing only the height of the last withdrawal and its current properties.
# Message types
# MsgSetWithdrawAddress
type MsgSetWithdrawAddress struct {
DelegatorAddress sdk.AccAddress `json:"delegator_address" yaml:"delegator_address"`
WithdrawAddress sdk.AccAddress `json:"withdraw_address" yaml:"withdraw_address"`
}
# MsgWithdrawDelegatorReward
// msg struct for delegation withdraw from a single validator
type MsgWithdrawDelegatorReward struct {
DelegatorAddress sdk.AccAddress `json:"delegator_address" yaml:"delegator_address"`
ValidatorAddress sdk.ValAddress `json:"validator_address" yaml:"validator_address"`
}
# MsgWithdrawValidatorCommission
type MsgWithdrawValidatorCommission struct {
ValidatorAddress sdk.ValAddress `json:"validator_address" yaml:"validator_address"`
}
# MsgFundCommunityPool
type MsgFundCommunityPool struct {
Amount sdk.Coins `json:"amount" yaml:"amount"`
Depositor sdk.AccAddress `json:"depositor" yaml:"depositor"`
}
# Proposals
# CommunityPoolSpendProposal
The distribution module defines a special proposal that, upon being passed, disburses the coins specified in Amount
to the Recipient
account using funds from the community pool.
type CommunityPoolSpendProposal struct {
Title string `json:"title" yaml:"title"`
Description string `json:"description" yaml:"description"`
Recipient sdk.AccAddress `json:"recipient" yaml:"recipient"`
Amount sdk.Coins `json:"amount" yaml:"amount"`
}
# Transitions
# Begin-Block
This section derives from the official Cosmos SDK docs, and is placed here for your convenience to understand the distribution module's parameters.
At the beginning of each block, the distribution module will set the proposer for determining distribution during endblock and distribute rewards for the previous block.
The fees received are transferred to the Distribution ModuleAccount
, which tracks the flow of coins in and out of the module. Fees are also allocated to the proposer, community fund, and global pool:
- Proposer: When a validator is the proposer of a round, that validator and its delegators receive 1-5% of the fee rewards.
- Global pool: The remainder of the funds is allocated to the global pool, where they are distributed proportionally by voting power to all bonded validators independent of whether they voted. This allocation is called social distribution. Social distribution is applied to the proposer validator in addition to the proposer reward.
The proposer reward is calculated from precommits Tendermint messages to incentivize validators to wait and include additional precommits in the block. All provision rewards are added to a provision reward pool, which each validator holds individually (ValidatorDistribution.ProvisionsRewardPool
).
func AllocateTokens(feesCollected sdk.Coins, feePool FeePool, proposer ValidatorDistribution,
sumPowerPrecommitValidators, totalBondedTokens, communityTax,
proposerCommissionRate sdk.Dec)
SendCoins(FeeCollectorAddr, DistributionModuleAccAddr, feesCollected)
feesCollectedDec = MakeDecCoins(feesCollected)
proposerReward = feesCollectedDec * (0.01 + 0.04
* sumPowerPrecommitValidators / totalBondedTokens)
commission = proposerReward * proposerCommissionRate
proposer.PoolCommission += commission
proposer.Pool += proposerReward - commission
communityFunding = feesCollectedDec * communityTax
feePool.CommunityFund += communityFunding
poolReceived = feesCollectedDec - proposerReward - communityFunding
feePool.Pool += poolReceived
SetValidatorDistribution(proposer)
SetFeePool(feePool)
# Parameters
The subspace for the distribution module is distribution
.
type GenesisState struct {
...
CommunityTax sdk.Dec `json:"community_tax" yaml:"community_tax"`
BaseProposerReward sdk.Dec `json:"base_proposer_reward" yaml:"base_proposer_reward"`
BonusProposerReward sdk.Dec `json:"bonus_proposer_reward" yaml:"bonus_proposer_reward"`
WithdrawAddrEnabled bool `json:"withdraw_addr_enabled"`
...
}
# Genesis parameters
The genesis parameters for the crisis module outlined in the Genesis Builder Script (opens new window) are as follows:
community_pool_allocation = TOTAL_ALLOCATION - pre_attack_allocation - \
post_attack_allocation - validator_allocation - emergency_allocation
# Distribution: community pool
genesis['app_state']['distribution']['fee_pool']['community_pool'] = [{
'denom': DENOM_GRAIN,
'amount': str(community_pool_allocation)
}]
# Distribution: set community tax to 0
genesis['app_state']['distribution']['params'] = {
'community_tax': '0.000000000000000000',
'base_proposer_reward': '0.010000000000000000',
'bonus_proposer_reward': '0.040000000000000000',
'withdraw_addr_enabled': True
}
# Distribution: module account registration
add_module_account(
genesis, 'distribution',
'paloma1jv65s3grqf6v6jl3dp4t6c9t9rk99cd8pm7utl',
str(community_pool_allocation), [])
# CommunityTax
- type:
Dec
# BaseProposerReward
- type:
Dec
# BonusProposerReward
- type:
Dec
# WithdrawAddrEnabled
- type:
bool