Mukan Erkin Törük
20afb5db80
Some checks failed
Build SimApp / build (amd64) (push) Waiting to run
Build SimApp / build (arm64) (push) Waiting to run
CodeQL / Analyze (push) Waiting to run
Build & Push / build (push) Waiting to run
Run Gosec / Gosec (push) Waiting to run
Lint / golangci-lint (push) Waiting to run
Checks dependencies and mocks generation / Check go mod tidy (push) Waiting to run
Checks dependencies and mocks generation / Check up to date mocks (push) Waiting to run
System Tests / setup (push) Waiting to run
System Tests / test-system (push) Blocked by required conditions
System Tests / test-system-legacy (push) Blocked by required conditions
Tests / Code Coverage / split-test-files (push) Waiting to run
Tests / Code Coverage / tests (00) (push) Blocked by required conditions
Tests / Code Coverage / tests (01) (push) Blocked by required conditions
Tests / Code Coverage / tests (02) (push) Blocked by required conditions
Tests / Code Coverage / tests (03) (push) Blocked by required conditions
Tests / Code Coverage / test-integration (push) Waiting to run
Tests / Code Coverage / test-e2e (push) Waiting to run
Tests / Code Coverage / repo-analysis (push) Blocked by required conditions
Tests / Code Coverage / test-sim-nondeterminism (push) Waiting to run
Tests / Code Coverage / test-clientv2 (push) Waiting to run
Tests / Code Coverage / test-core (push) Waiting to run
Tests / Code Coverage / test-depinject (push) Waiting to run
Tests / Code Coverage / test-errors (push) Waiting to run
Tests / Code Coverage / test-math (push) Waiting to run
Tests / Code Coverage / test-schema (push) Waiting to run
Tests / Code Coverage / test-collections (push) Waiting to run
Tests / Code Coverage / test-cosmovisor (push) Waiting to run
Tests / Code Coverage / test-confix (push) Waiting to run
Tests / Code Coverage / test-store (push) Waiting to run
Tests / Code Coverage / test-log (push) Waiting to run
Tests / Code Coverage / test-x-tx (push) Waiting to run
Tests / Code Coverage / test-x-nft (push) Waiting to run
Tests / Code Coverage / test-x-circuit (push) Waiting to run
Tests / Code Coverage / test-x-feegrant (push) Waiting to run
Tests / Code Coverage / test-x-evidence (push) Waiting to run
Tests / Code Coverage / test-x-upgrade (push) Waiting to run
Tests / Code Coverage / test-tools-benchmark (push) Waiting to run
Build & Push SDK Proto Builder / build (push) Has been cancelled
61 lines
2.6 KiB
Markdown
61 lines
2.6 KiB
Markdown
# ADR 17: Historical Header Module
|
|
|
|
## Changelog
|
|
|
|
* 26 November 2019: Start of first version
|
|
* 2 December 2019: Final draft of first version
|
|
|
|
## Context
|
|
|
|
In order for the Cosmos SDK to implement the [IBC specification](https://github.com/cosmos/ics), modules within the Cosmos SDK must have the ability to introspect recent consensus states (validator sets & commitment roots) as proofs of these values on other chains must be checked during the handshakes.
|
|
|
|
## Decision
|
|
|
|
The application MUST store the most recent `n` headers in a persistent store. At first, this store MAY be the current Merklised store. A non-Merklised store MAY be used later as no proofs are necessary.
|
|
|
|
The application MUST store this information by storing new headers immediately when handling `abci.RequestBeginBlock`:
|
|
|
|
```go
|
|
func BeginBlock(ctx sdk.Context, keeper HistoricalHeaderKeeper, req abci.RequestBeginBlock) abci.ResponseBeginBlock {
|
|
info := HistoricalInfo{
|
|
Header: ctx.BlockHeader(),
|
|
ValSet: keeper.StakingKeeper.GetAllValidators(ctx), // note that this must be stored in a canonical order
|
|
}
|
|
keeper.SetHistoricalInfo(ctx, ctx.BlockHeight(), info)
|
|
n := keeper.GetParamRecentHeadersToStore()
|
|
keeper.PruneHistoricalInfo(ctx, ctx.BlockHeight() - n)
|
|
// continue handling request
|
|
}
|
|
```
|
|
|
|
Alternatively, the application MAY store only the hash of the validator set.
|
|
|
|
The application MUST make these past `n` committed headers available for querying by Cosmos SDK modules through the `Keeper`'s `GetHistoricalInfo` function. This MAY be implemented in a new module, or it MAY also be integrated into an existing one (likely `x/staking` or `x/ibc`).
|
|
|
|
`n` MAY be configured as a parameter store parameter, in which case it could be changed by `ParameterChangeProposal`s, although it will take some blocks for the stored information to catch up if `n` is increased.
|
|
|
|
## Status
|
|
|
|
Proposed.
|
|
|
|
## Consequences
|
|
|
|
Implementation of this ADR will require changes to the Cosmos SDK. It will not require changes to Tendermint.
|
|
|
|
### Positive
|
|
|
|
* Easy retrieval of headers & state roots for recent past heights by modules anywhere in the Cosmos SDK.
|
|
* No RPC calls to Tendermint required.
|
|
* No ABCI alterations required.
|
|
|
|
### Negative
|
|
|
|
* Duplicates `n` headers data in Tendermint & the application (additional disk usage) - in the long term, an approach such as [this](https://github.com/tendermint/tendermint/issues/4210) might be preferable.
|
|
|
|
### Neutral
|
|
|
|
(none known)
|
|
|
|
## References
|
|
|
|
* [ICS 2: "Consensus state introspection"](https://github.com/cosmos/ibc/tree/master/spec/core/ics-002-client-semantics#consensus-state-introspection)
|