CollatorSelection¶

Calls¶

leave_intent¶

Deregister origin as a collator candidate. Note that the collator can only leave on session change. The CandidacyBond will be unreserved immediately.

This call will fail if the total number of candidates would drop below MinCandidates.

This call is not available to Invulnerable collators.

Attributes¶

No attributes

Python¶

call = substrate.compose_call(
    'CollatorSelection', 'leave_intent', {}
)

register_as_candidate¶

Register this account as a collator candidate. The account must (a) already have registered session keys and (b) be able to reserve the CandidacyBond.

This call is not available to Invulnerable collators.

Attributes¶

No attributes

Python¶

call = substrate.compose_call(
    'CollatorSelection', 'register_as_candidate', {}
)

set_candidacy_bond¶

Set the candidacy bond amount.

Attributes¶

Name	Type
bond	`BalanceOf<T>`

Python¶

call = substrate.compose_call(
    'CollatorSelection', 'set_candidacy_bond', {'bond': 'u128'}
)

set_desired_candidates¶

Set the ideal number of collators (not including the invulnerables). If lowering this number, then the number of running collators could be higher than this figure. Aside from that edge case, there should be no other way to have more collators than the desired number.

Attributes¶

Name	Type
max	`u32`

Python¶

call = substrate.compose_call(
    'CollatorSelection', 'set_desired_candidates', {'max': 'u32'}
)

set_invulnerables¶

Set the list of invulnerable (fixed) collators.

Attributes¶

Name	Type
new	`Vec<T::AccountId>`

Python¶

call = substrate.compose_call(
    'CollatorSelection', 'set_invulnerables', {'new': ['AccountId']}
)

Events¶

CandidateAdded¶

Attributes¶

Name	Type	Composition
account_id	`T::AccountId`	`AccountId`
deposit	`BalanceOf<T>`	`u128`

CandidateRemoved¶

Attributes¶

Name	Type	Composition
account_id	`T::AccountId`	`AccountId`

NewCandidacyBond¶

Attributes¶

Name	Type	Composition
bond_amount	`BalanceOf<T>`	`u128`

NewDesiredCandidates¶

Attributes¶

Name	Type	Composition
desired_candidates	`u32`	`u32`

NewInvulnerables¶

Attributes¶

Name	Type	Composition
invulnerables	`Vec<T::AccountId>`	`['AccountId']`

Storage functions¶

CandidacyBond¶

Fixed amount to deposit to become a collator.

When a collator calls leave_intent they immediately receive the deposit back.

Python¶

result = substrate.query(
    'CollatorSelection', 'CandidacyBond', []
)

Return value¶

'u128'

Candidates¶

The (community, limited) collation candidates.

Python¶

result = substrate.query(
    'CollatorSelection', 'Candidates', []
)

Return value¶

[{'deposit': 'u128', 'who': 'AccountId'}]

DesiredCandidates¶

Desired number of candidates.

This should ideally always be less than [Config::MaxCandidates] for weights to be correct.

Python¶

result = substrate.query(
    'CollatorSelection', 'DesiredCandidates', []
)

Return value¶

'u32'

Invulnerables¶

The invulnerable, fixed collators.

Python¶

result = substrate.query(
    'CollatorSelection', 'Invulnerables', []
)

Return value¶

['AccountId']

LastAuthoredBlock¶

Last block authored by collator.

Python¶

result = substrate.query(
    'CollatorSelection', 'LastAuthoredBlock', ['AccountId']
)

Return value¶

'u32'

Errors¶

AlreadyCandidate¶

User is already a candidate

AlreadyInvulnerable¶

User is already an Invulnerable

NoAssociatedValidatorId¶

Account has no associated validator ID

NotCandidate¶

User is not a candidate

Permission¶

Permission issue

TooFewCandidates¶

Too few candidates

TooManyCandidates¶

Too many candidates

TooManyInvulnerables¶

Too many invulnerables

Unknown¶

Unknown error

ValidatorNotRegistered¶

Validator ID is not yet registered