## Issue Addressed
#4040
## Proposed Changes
- Add the `always_prefer_builder_payload` field to `Config` in `beacon_node/client/src/config.rs`.
- Add that same field to `Inner` in `beacon_node/execution_layer/src/lib.rs`
- Modify the logic for picking the payload in `beacon_node/execution_layer/src/lib.rs`
- Add the `always-prefer-builder-payload` flag to the beacon node CLI
- Test the new flags in `lighthouse/tests/beacon_node.rs`
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
Closes#3896Closes#3998Closes#3700
## Proposed Changes
- Optimise the calculation of withdrawals for payload attributes by avoiding state clones, avoiding unnecessary state advances and reading from the snapshot cache if possible.
- Use the execution layer's payload attributes cache to avoid re-calculating payload attributes. I actually implemented a new LRU cache just for withdrawals but it had the exact same key and most of the same data as the existing payload attributes cache, so I deleted it.
- Add a new SSE event that fires when payloadAttributes are calculated. This is useful for block builders, a la https://github.com/ethereum/beacon-APIs/issues/244.
- Add a new CLI flag `--always-prepare-payload` which forces payload attributes to be sent with every fcU regardless of connected proposers. This is intended for use by builders/relays.
For maximum effect, the flags I've been using to run Lighthouse in "payload builder mode" are:
```
--always-prepare-payload \
--prepare-payload-lookahead 12000 \
--suggested-fee-recipient 0x0000000000000000000000000000000000000000
```
The fee recipient is required so Lighthouse has something to pack in the payload attributes (it can be ignored by the builder). The lookahead causes fcU to be sent at the start of every slot rather than at 8s. As usual, fcU will also be sent after each change of head block. I think this combination is sufficient for builders to build on all viable heads. Often there will be two fcU (and two payload attributes) sent for the same slot: one sent at the start of the slot with the head from `n - 1` as the parent, and one sent after the block arrives with `n` as the parent.
Example usage of the new event stream:
```bash
curl -N "http://localhost:5052/eth/v1/events?topics=payload_attributes"
```
## Additional Info
- [x] Tests added by updating the proposer re-org tests. This has the benefit of testing the proposer re-org code paths with withdrawals too, confirming that the new changes don't interact poorly.
- [ ] Benchmarking with `blockdreamer` on devnet-7 showed promising results but I'm yet to do a comparison to `unstable`.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
NA
## Proposed Changes
As discovered in #4034, Lighthouse is not accepting `latest_valid_hash == None` in an `INVALID` response to `newPayload`. The `null`/`None` response *was* illegal at one point, however it was added in https://github.com/ethereum/execution-apis/pull/254.
This PR brings Lighthouse in line with the standard and should fix the root cause of what #4034 patched around.
## Additional Info
NA
## Issue Addressed
Cleans up all the remnants of 4844 in capella. This makes sure when 4844 is reviewed there is nothing we are missing because it got included here
## Proposed Changes
drop a bomb on every 4844 thing
## Additional Info
Merge process I did (locally) is as follows:
- squash merge to produce one commit
- in new branch off unstable with the squashed commit create a `git revert HEAD` commit
- merge that new branch onto 4844 with `--strategy ours`
- compare local 4844 to remote 4844 and make sure the diff is empty
- enjoy
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
NA
## Proposed Changes
Our `ERRO` stream has been rather noisy since the merge due to some unexpected behaviours of builders and EEs. Now that we've been running post-merge for a while, I think we can drop some of these `ERRO` to `WARN` so we're not "crying wolf".
The modified logs are:
#### `ERRO Execution engine call failed`
I'm seeing this quite frequently on Geth nodes. They seem to timeout when they're busy and it rarely indicates a serious issue. We also have logging across block import, fork choice updating and payload production that raise `ERRO` or `CRIT` when the EE times out, so I think we're not at risk of silencing actual issues.
#### `ERRO "Builder failed to reveal payload"`
In #3775 we reduced this log from `CRIT` to `ERRO` since it's common for builders to fail to reveal the block to the producer directly whilst still broadcasting it to the networ. I think it's worth dropping this to `WARN` since it's rarely interesting.
I elected to stay with `WARN` since I really do wish builders would fulfill their API promises by returning the block to us. Perhaps I'm just being pedantic here, I could be convinced otherwise.
#### `ERRO "Relay error when registering validator(s)"`
It seems like builders and/or mev-boost struggle to handle heavy loads of validator registrations. I haven't observed issues with validators not actually being registered, but I see timeouts on these endpoints many times a day. It doesn't seem like this `ERRO` is worth it.
#### `ERRO Error fetching block for peer ExecutionLayerErrorPayloadReconstruction`
This means we failed to respond to a peer on the P2P network with a block they requested because of an error in the `execution_layer`. It's very common to see timeouts or incomplete responses on this endpoint whilst the EE is busy and I don't think it's important enough for an `ERRO`. As long as the peer count stays high, I don't think the user needs to be actively concerned about how we're responding to peers.
## Additional Info
NA
* Use Local Payload if More Profitable than Builder
* Rename clone -> clone_from_ref
* Minimize Clones of GetPayloadResponse
* Cleanup & Fix Tests
* Added Tests for Payload Choice by Profit
* Fix Outdated Comments
