Fetcher fetch only attestation data with committee index 0 #3980
Description
🎯 Problem to be solved
Currently our fetcher fetches attestation data for all committee indices that need to attest. This is done, because some VCs are requesting attester data for the specific committee indices and not 0. Recently though they have started fixing that (check #3913 ). As a start, it would be nice if we add a feature flag that makes fetcher fetch only attestation with committee index 0 for the users that are already using VCs. This will improve couple of things:
- Reduce the amount of the requests to the BN;
- Reduce memory usage of Charon;
- Avoid issues where we have different head for the same slot, that caused issues before (most likely it will result in more head vote misses though).
🛠️ Proposed solution
- Add a new feature flag. Or simply a flag? If it we choose a feature flag we know we will move it to stable soon, when all VCs fix the issue.
- Set BN to only ask for attestation data with committee index 0.
- Do not save twice attestation data in DB, as we currently do. We do save attestation data for the actual attestation committee index + committee index 0. No reason to do that anymore.
🧪 Tests
- Tested by new automated unit/integration/smoke tests
- Manually tested on core team/canary/test clusters
- Manually tested on local compose simnet