[−][src]Crate pallet_im_online
I'm online Module
If the local node is a validator (i.e. contains an authority key), this module gossips a heartbeat transaction with each new session. The heartbeat functions as a simple mechanism to signal that the node is online in the current era.
Received heartbeats are tracked for one era and reset with each new era. The module exposes two public functions to query if a heartbeat has been received in the current era or session.
The heartbeat is a signed transaction, which was signed using the session key and includes the recent best block number of the local validators chain as well as the NetworkState. It is submitted as an Unsigned Transaction via off-chain workers.
Interface
Public Functions
is_online
- True if the validator sent a heartbeat in the current session.
Usage
use frame_support::{decl_module, dispatch}; use frame_system::{self as system, ensure_signed}; use pallet_im_online::{self as im_online}; pub trait Trait: im_online::Trait {} decl_module! { pub struct Module<T: Trait> for enum Call where origin: T::Origin { #[weight = 0] pub fn is_online(origin, authority_index: u32) -> dispatch::DispatchResult { let _sender = ensure_signed(origin)?; let _is_online = <im_online::Module<T>>::is_online(authority_index); Ok(()) } } }
Dependencies
This module depends on the Session module.
Modules
ed25519 | |
sr25519 |
Structs
GenesisConfig | Genesis config for the module, allow to build genesis storage. |
Heartbeat | Heartbeat which is sent/received. |
Module | |
UnresponsivenessOffence | An offence that is filed if a validator didn't send a heartbeat message. |
Enums
Call | Dispatchable calls. |
Error | Error for the im-online module. |
RawEvent | Events for this module. |
Traits
Trait |
Type Definitions
AuthIndex | |
Event |