EPF Dev Update #8

My focus this week has been on Lighthouse interop testing in preparation for EIP-4844 devnet v3, which was launched a couple of days ago with just one client pair (Prysm/Geth), and we're hoping to to add Lighthouse to the mix very soon (more details in below section).

We've achieved a great milestone this week to have Lighthouse integrated into the eip4844-interop repo and have passed both the blob transction tests and fee market tests! Big shoutout to @Inphi, @realbigsean and the Lighthouse team

Areas I worked on this week:

• Debug Lighthouse sync issues
• Add Lighthouse to eip-4844-interop repo (eip4844-interop#77)
• Add Beacon API endpoint to download blobs by block id (lighthouse#3830)

For next week/year:

• Set up a Lighthouse/Geth node on EIP-4844 devnet-3
• Beacon API & Builder Spec updates for EIP-4844
  • beacon-APIs#271
  • builder-specs#58
  • I've addressed all review comments by @0xGabi and @ralexstokes, PRs waiting for review
• Implement builder updates in Lighthouse
  • draft PR from last week here, to be continued: lighthouse#3808

Debugging Lighthouse Sync issues & interop testing

https://github.com/Inphi/eip4844-interop/pull/77 (Merged)

PR to add Lighthouse to interop repo was finally merged this morning after a few days of hard work with @realbigsean and @Inphi \o/

Lighthouse Sync issues

Earlier in the week I spent quite a bit of time using the Clion Rust debugger to troubleshoot Lighthouse sync issues, and it was quite fun and rewarding! Although I wasn't able to find out what the root cause was, the Lighthouse team did, and fixed the sync issues in this PR.

I was able to run a local network of 4 Lighthouse/Geth nodes to verify the sync works - by starting 4 nodes, and immediately shutdown one node, then starting that node after 160 slots (to make sure epoch 3, a post merge 4844 epoch is finalized).

Interop testing

After confirming Lighthouse sync works locally, I moved back to the interop testing task I was working earlier, given that Lighthouse was ready for it. The interop repo contains a few important tests for EIP-4844, including a blob tx test, which sends a blob tx to the EL, and download it from mulitple Lighthouse beacon nodes.

With @Inphi's help and a couple of fixes, we finally got Lighthouse passing both the blob transaction tests and fee market tests!

Add Beacon API endpoint to download blobs by block id

I found it quite challenging to test blobs when I was doing interop testing, as there is no Beacon API available for this. I raised an issue in the Beacon API spec repo, but this hasn't been worked on yet.

So I suggested adding an endpoint to the Beacon API under /lighthouse, which consists of only non standard endpoints for dev and other purposes. @realbigsean agreed that it would be helpful for debugging, so I went ahead and started implementation.

I've created a draft PR here, and will start testing this soon: https://github.com/sigp/lighthouse/pull/3830

Running a Lighthouse/Geth node on EIP-4844 devnet-3

I haven't been able to a Lighthouse/Geth node working yet, as there are still some known issues that are currently being fixed, but I've dropped some notes on running Lighthouse/Geth combo here (credit goes to @realbigsean): https://github.com/jimmygchen/devnet-v3

Hopefully I'll get a node running in the next few days!

Other small PRs

• Various small fixes to 4844 branch (lighthouse#3825): log and comment improvements
• Use bootnode binary variable in testnet scripts (lighthouse#3823): small fix to local testnet script

Good resources

• Terence's notes on how 4844 impacts mev builders, relayers and mev-boost: nice explainer on the changes and reasons behind, especially on the builder/relayer side, would be very useful for relay-specs update

and That's it..

..for this year! :) Thanks for reading and have a happy holiday everyone!

See you in the next one