DVT Compatibility

[AgeManning]

Description

There are two endpoints in the beaconapi specs, specifically designed for DVT middleware:

• https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Validator/submitBeaconCommitteeSelections
• https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Validator/submitSyncCommitteeSelections

We have a --distributed flag in the VC now. We should implement these endpoints on the BN and when this flag is set on the VC use these endpoints.

There is further information and testing links in this comment: #4867 (comment)

[michaelsproul]

My understanding is that we do not need to implement these on the BN: just to use them from the VC.

[michaelsproul]

I will investigate

[OisinKyne]

My understanding is that we do not need to implement these on the BN: just to use them from the VC.

Correct. You just need to call them with the VC, charon returns an aggregated signature in exchange for the partial one sent, and then the aggregation selection process continues as normal from there :)

[OisinKyne]

Hey @michaelsproul, have you had a chance to take a look at this issue yet? :)

[michaelsproul]

@OisinKyne No, sorry! It fell off my todo list, will try to make some time for it now Electra is stabilising

[michaelsproul]

@chong-he is going to take a look at this.

This is the point to get started (for the aggregate attestation API):

lighthouse/validator_client/validator_services/src/duties_service.rs

Lines 128 to 150 in 029b4f2

	async fn make_selection_proof<T: SlotClock + 'static, E: EthSpec>(
	duty: &AttesterData,
	validator_store: &ValidatorStore<T, E>,
	spec: &ChainSpec,
	) -> Result<Option<SelectionProof>, Error> {
	let selection_proof = validator_store
	.produce_selection_proof(duty.pubkey, duty.slot)
	.await
	.map_err(Error::FailedToProduceSelectionProof)?;
	selection_proof
	.is_aggregator(duty.committee_length as usize, spec)
	.map_err(Error::InvalidModulo)
	.map(|is_aggregator| {
	if is_aggregator {
	Some(selection_proof)
	} else {
	// Don't bother storing the selection proof if the validator isn't an
	// aggregator, we won't need it.
	None
	}
	})
	}

We need to:

• Define the type for BeaconCommitteeSelectionRequest (from beacon-api).
• If --distributed mode is enableld: add an HTTP call to the aggregate committee API (using first_success on the list of beacon nodes is fine).
• Use the response from the API as the selection_proof, and keep the same logic for checking whether the validator is an aggregator (is_aggregator).

[OisinKyne]

Hey @chong-he, let me know if you have any questions on what's involved. :)

[chong-he]

Hey @chong-he, let me know if you have any questions on what's involved. :)

Hey there! I have created a PR for this issue and going to test the beacon committee aggregator. I see your reply here that there is a tool ready for testing: #4867 (comment), so going to give this a try

[chong-he]

Hi @OisinKyne , I am setting up a Kurtosis-Charon testnet to get familiar with Obol before the PR #7016 change. I got the testnet up and it is producing blocks normally. But I wanted to know how Charon works and it I have set it up properly, so I have a few questions:

1. How to know which validators are having partial keys, which are full keys? or once make run-charon-lighthouse is run, the validators are already all using partial keys?

2. As I understand Lighthouse VC still doesn't support the endpoint now, so I thought the aggregated attestations will not work, but I am seeing aggregated attestations in the VC logs, and also in Charon:

"log":"03:21:35.326 INFO tracker    Broadcasted attestation included on-chain {\"block_slot\": 4068, \"attestation_slot\": 4067, \"pubkey\": \"b3f_2d9\", \"inclusion_delay\": 1, \"broadcast_delay\": \"4.712200459s\", \"aggregate_len\": 24, \"aggregated\": true}\n","stream":"stderr","time":"2025-02-27T03:21:35.32649264Z"}

3. From the repository, at step 8, there is a Grafana instance that I couldn't access. I asked in the Discord channel about this: https://discord.com/channels/849256203614945310/970759460693901362/1344318464160174090, appreciate if you can provide some insights in this.

I also reached out to you via Discord DM @Okyne so feel free to reply there.

Thanks