pezkuwichain
3139ffa25e
- snowbridge-pezpallet-* → pezsnowbridge-pezpallet-* (201 refs) - pallet/ directories → pezpallet/ (4 locations) - Fixed pezpallet.rs self-include recursion bug - Fixed sc-chain-spec hardcoded crate name in derive macro - Reverted .pezpallet_by_name() to .pallet_by_name() (subxt API) - Added BizinikiwiConfig type alias for zombienet tests - Deleted obsolete session state files Verified: pezsnowbridge-pezpallet-*, pezpallet-staking, pezpallet-staking-async, pezframe-benchmarking-cli all pass cargo check
51 lines
3.4 KiB
Markdown
51 lines
3.4 KiB
Markdown
# Teyrchains Finality Relay
|
|
|
|
The teyrchains finality relay works with two chains - source relay chain and target chain (which may be standalone
|
|
chain, relay chain or a teyrchain). The source chain must have the
|
|
[`paras` pezpallet](https://github.com/paritytech/polkadot/tree/master/runtime/parachains/src/paras) deployed at its
|
|
runtime. The target chain must have the [bridge teyrchains pezpallet](../../modules/teyrchains/) deployed at its runtime.
|
|
|
|
The relay is configured to submit heads of one or several teyrchains. It pokes source chain periodically and compares
|
|
teyrchain heads that are known to the source relay chain to heads at the target chain. If there are new heads,
|
|
the relay submits them to the target chain.
|
|
|
|
More: [Teyrchains Finality Relay Sequence Diagram](../../docs/teyrchains-pez-finality-relay.html).
|
|
|
|
## How to Use the Teyrchains Finality Relay
|
|
|
|
There are only two traits that need to be implemented. The [`SourceChain`](./src/teyrchains_loop.rs) implementation
|
|
is supposed to connect to the source chain node. It must be able to read teyrchain heads from the `Heads` map of
|
|
the [`paras` pezpallet](https://github.com/paritytech/polkadot/tree/master/runtime/parachains/src/paras).
|
|
It also must create storage proofs of `Heads` map entries, when required.
|
|
|
|
The [`TargetChain`](./src/teyrchains_loop.rs) implementation connects to the target chain node. It must be able
|
|
to return the best known head of given teyrchain. When required, it must be able to craft and submit teyrchains
|
|
finality delivery transaction to the target node.
|
|
|
|
The main entrypoint for the crate is the [`run` function](./src/teyrchains_loop.rs), which takes source and target
|
|
clients and [`TeyrchainSyncParams`](./src/teyrchains_loop.rs) parameters. The most important parameter is the
|
|
`teyrchains` - it is the set of teyrchains, which relay tracks and updates. The other important parameter that
|
|
may affect the relay operational costs is the `strategy`. If it is set to `Any`, then the finality delivery
|
|
transaction is submitted if at least one of tracked teyrchain heads is updated. The other option is `All`. Then
|
|
the relay waits until all tracked teyrchain heads are updated and submits them all in a single finality delivery
|
|
transaction.
|
|
|
|
## Teyrchain Finality Relay Metrics
|
|
|
|
Every teyrchain in PezkuwiChain is identified by the 32-bit number. All metrics, exposed by the teyrchains finality
|
|
relay have the `teyrchain` label, which is set to the teyrchain id. And the metrics are prefixed with the prefix,
|
|
that depends on the name of the source relay and target chains. The list below shows metrics names for
|
|
pezkuwichain (source relay chain) to BridgeHubzagros (target chain) teyrchains finality relay. For other chains, simply
|
|
change chain names. So the metrics are:
|
|
|
|
- `pezkuwichain_to_BridgeHubzagros_Teyrchains_best_teyrchain_block_number_at_source` - returns best known teyrchain block
|
|
number, registered in the `paras` pezpallet at the source relay chain (pezkuwichain in our example);
|
|
|
|
- `pezkuwichain_to_BridgeHubzagros_Teyrchains_best_teyrchain_block_number_at_target` - returns best known teyrchain block
|
|
number, registered in the bridge teyrchains pezpallet at the target chain (BridgeHubzagros in our example).
|
|
|
|
If relay operates properly, you should see that
|
|
the `pezkuwichain_to_BridgeHubzagros_Teyrchains_best_teyrchain_block_number_at_target` tries to reach
|
|
the `pezkuwichain_to_BridgeHubzagros_Teyrchains_best_teyrchain_block_number_at_source`.
|
|
And the latter one always increases.
|