returnfmt.Errorf("selected output is after finalized head output block: %v, finalized block: %v",output.L2BlockNumber.Uint64(),l2FinalizedHead.NumberU64())
Copy `.env.example` into a new file named `.env`, then set the environment variables listed there.
Once your environment variables have been set, run the service via:
Copy `.env.example` into a new file named `.env`, then set the environment variables listed there. Additional env setting are listed on `--help`. If running the fault detector against
a custom op chain, the necessary contract addresses must also be set associated with the op-chain.
- Bedrock: `OptimismPortal`
- Legacy: `StateCommitmentChain`
Once your environment variables or flags have been set, run the service via:
```
yarn start
...
...
@@ -34,8 +39,14 @@ yarn start
The `fault-detector` detects differences between the transaction results generated by your local Optimism node and the transaction results actually published to Ethereum.
Currently, transaction results take the form of [the root of the Optimism state trie](https://medium.com/@eiki1212/ethereum-state-trie-architecture-explained-a30237009d4e).
For every Optimism block, the state root of the block is published to the [`StateCommitmentChain`](https://github.com/ethereum-optimism/optimism/blob/39b7262cc3ffd78cd314341b8512b2683c1d9af7/packages/contracts/contracts/L1/rollup/StateCommitmentChain.sol) contract on Ethereum.
- For bedrock chains, the state root of the block is published to the [`L2OutputOracle`](https://github.com/ethereum-optimism/optimism/blob/39b7262cc3ffd78cd314341b8512b2683c1d9af7/packages/contracts-bedrock/contracts/L1/L2OutputOracle.sol) contract on Ethereum.
-***Note***: The service accepts the `OptimismPortal` as a flag instead of the `L2OutputOracle` for backwards compatibility with early versions of these contracts. The `L2OutputOracle`
is inferred from the portal contract.
- For bedrock chains, the state root of the block is published to the [`StateCommitmentChain`](https://github.com/ethereum-optimism/optimism/blob/39b7262cc3ffd78cd314341b8512b2683c1d9af7/packages/contracts/contracts/L1/rollup/StateCommitmentChain.sol) contract on Ethereum.
We can therefore detect differences by, for each block, checking the state root of the given block as reported by an Optimism node and the state root as published to Ethereum.
In order for the fault detector to differentiate between bedrock and legacy chains, please make sure to specify `--bedrock`.
We export a series of Prometheus metrics that you can use to trigger alerting when issues are detected.
Check the list of available metrics via `yarn start --help`:
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...
@@ -52,6 +63,9 @@ Options:
--startbatchindex Batch index to start checking from. Setting it to -1 will cause the fault detector to find the first state batch index that has not yet passed the fault proof window (env: FAULT_DETECTOR__START_BATCH_INDEX, default value: -1)
--loopintervalms Loop interval in milliseconds (env: FAULT_DETECTOR__LOOP_INTERVAL_MS)
--bedrock Whether or not the service is running against a Bedrock chain (env: FAULT_DETECTOR__BEDROCK, default value: false)
--optimismportaladdress[Custom Bedrock Chains] Deployed OptimismPortal contract address. Used to retrieve necessary info for ouput verification (env: FAULT_DETECTOR__OPTIMISM_PORTAL_ADDRESS, default 0x0)
--statecommitmentchainaddress[Custom Legacy Chains] Deployed StateCommitmentChain contract address. Used to fetch necessary info for output verification. (env: FAULT_DETECTOR__STATE_COMMITMENT_CHAIN_ADDRESS, default 0x0)
--port Port for the app server (env: FAULT_DETECTOR__PORT)
--hostname Hostname for the app server (env: FAULT_DETECTOR__HOSTNAME)
