--- tags: eth2devs description: Notes from the regular proof of stake [Eth2] implementers call image: https://benjaminion.xyz/f/favicon-96x96.png --- # PoS Implementers’ Call #81 - 2022-02-10 [Quick contemporaneous notes by Ben Edgington; fka "Eth2 Implementers' Call"] Agenda: https://github.com/ethereum/pm/issues/475 Livestream: https://youtu.be/DtwTZWZrZMY ## Kiln office hours ### Auth and exchange additions to kiln Kiln v1 is out. Two known issues to be put into Kiln v2: - [ethereum/execution-apis#167](https://github.com/ethereum/execution-apis/pull/167) - authentication for engine api (note, it's now on a new port) - [ethereum/execution-apis#172](https://github.com/ethereum/execution-apis/pull/172) - add engine_exchangeTransitionConfigurationV1 ### Kiln milestones New [tracker doc](https://notes.ethereum.org/@timbeiko/kiln-milestones). Similar process to previous devnets. Be sure to run optimistic sync across client combos. Once sufficient milestones have been passed we'll make a persistent version and release it to the public. It will be the last testnet before we fork the existing Eth1 testnets. ### Testing updates - [Lightclient] has merged a PR to mergemock to support Kiln - Pari mentioned [the Kurtosis tool](https://notes.ethereum.org/@ExXcnR0-SJGthjz1dwkA1A/H11OzhRAK) for running private test infrastructure. Can be used to test locally before joining any devnets. ### Kiln client / experimental build status Consensus clients: - Teku has a Kiln engine API implementation (but no authentication yet). Switch between Kintsugi and Kiln via a CLI flag, `--Xee-version kiln` - Prysm has the implementation and passes tests, but no auth yet. - Lodestar running against Nethermind and Geth. No auth yet. - Nimbus, no authentication, but passing tests on local testnet. - Lighthouse and Grandine implementations are in progress. Execution clients: - Versions of Geth and Nethermind are running against Lodestar. [PaulH] [PR #190](https://github.com/ethereum/beacon-APIs/pull/190) on API repos on how to respond to requests during optimistic sync. We should standardise this soon. Also, can we add values/metadata without bumping a version number? [AdrianS] This would be desirable. **Action: please review** ## Merge topics [Mikhail] Execution payload deduplication. In the current design they are stored on both the consensus and execution layers. There is [a PR](https://github.com/ethereum/execution-apis/pull/146) to store only on execution side. Default currently is _not_ to implement this PR with the Merge unless someone wants to push it. But we can upgrade without a hardfork later if desired. [Danny] In practice, this amounts to 4 months of duplicated data (clients can prune older than that). Some EIPs are planned that increase block size which will exacerbate the problem. Probably not urgent, though. Estimate size currently as ~80GB for 4 months data. [Terence] are clients implementing indexing based on payload hash? Lighthouse is trying to avoid creating an index for this. Would be an issue for Nimbus, which prefers slot numbers over hashes. [Terence] More concerned about the API, so that execution layer can serve payloads. [Danny] Could do hash-based lookup on exec side (as per current PR 146), or could do a `byRange` request. There was some [previous discussion](https://github.com/ethereum/execution-apis/issues/137). **Action: please add to the discussion** [PaulH] Lighthouse is trying to collect the `feeRecipient` info from current users (for Eth1 coinbase post-merge). All clients will need to do this and document it. [Terence] Is there any doc around this yet? Teku has [already implemented](https://github.com/ConsenSys/teku/pull/4894) the feature; should we have a uniform approach/standard? [Danny] Also need to add good defaults. [PaulH] It's similar to dealing with per-validator graffiti. On defaults, should prompt users for info if it's not already set up, and refuse to start. [Danny] Will add this to the ecosystem outreach list. [Tim] Merge community call happening tomorrow. Always helpful to have some client devs around! See PM repo issue. Aiming to get some applications to do end-to-end deployments on Kiln. In particular looking for tracing-heavy applications (e.g. exchanges, block explorers) ## Spec discussion and AOB Eth1 Shanghai fork - working on a feature set for consensus-side counterpart: - EIP for withdrawals on exec layer is in progress, need to mirror this on the consensus layer. - Jacek's clean up of historical roots could be added. - [Tim] Plus any work needed to support Vitalik's [blob transactions](https://github.com/ethereum/pm/issues/459#issuecomment-1029529089) proposal. [V] The more complex version is currently winning; this puts more work on the consensus side. But it's not huge: block producers have the most work to do. This will be hacked on at EthDenver. Dank Sharding educational workshop might happen next week. In planning. * * * # Chat highlights From danny to Everyone 02:03 PM : https://github.com/ethereum/pm/issues/475 https://notes.ethereum.org/@timbeiko/kiln-milestones From pari to Everyone 02:10 PM : Would be great if client teams can share info on builds here: https://notes.ethereum.org/D5xK4XrmTb6MKGudf_hcrg From terence(prysmaticlabs) to Everyone 02:10 PM : https://gist.github.com/rauljordan/dd5aef5c35a98ae67989601c83aafde1 From pari to Everyone 02:12 PM : Docs for getting started with kurtosis can be found here: https://notes.ethereum.org/@ExXcnR0-SJGthjz1dwkA1A/H11OzhRAK From Adrian Sutton to Everyone 02:13 PM : Switch teku to kiln mode for the Engine API: --Xee-version kiln From pari to Everyone 02:14 PM : So the following would be the participants for merge-devnet-4, lemme know if other clients also feel ready. CL: teku, lodestar, nimbus. EL: geth, nethermind From danny to Everyone 02:14 PM : https://github.com/ethereum/beacon-APIs/pull/190 From Mikhail Kalinin to Everyone 02:17 PM : https://github.com/ethereum/execution-apis/pull/146 From Mikhail Kalinin to Everyone 02:23 PM : https://github.com/ethereum/execution-apis/issues/137 discussion thread ^ From Adrian Sutton to Everyone 02:27 PM : Teku implementation with some details of how it works in the PR description: https://github.com/ConsenSys/teku/pull/4894 From Mikhail Kalinin to Everyone 02:32 PM : When are we having the first kiln devnet? From pari to Everyone 02:33 PM : I will plan to get one up tomorrow, can’t guarantee it will work. If it fails, I’ll try again on monday. Calling it merge-devnet-4 From Mikhail Kalinin to Everyone 02:33 PM : 👍 From Tim Beiko to Everyone 02:36 PM : Link for context: https://github.com/ethereum/pm/issues/459#issuecomment-1029529089