Portal Implementers Call #49 - March 31st

Protocol Calls & happenings
1

Meeting Info

Agenda

GitHub Issue

2

This week’s call notes:

1. Team update

  • Update on Trin & Glados by Kolby

    • Formalize the new e2hs file format to handle all EL blocks, which simplifies bridging process
    • Implemented e2hs, incl. adding reader & writer in e2store crate
    • Published e2store crates available for external projects to use
    • Fixed a utp packet handling bug, where 1st part of transfer is ignored by recipient if the STATE response to SYN is dropped
    • Cleaned up redundant test vectors
    • Glados: Now display header by numbers on the latest block status graph

  • Update on Ultralight by ScottyPoi

    • Added protocol versioning to ENRs and preparing for the PR on accept/decline code change
    • Updating EthereumJS to support EIP-4444 and drop day by integrating Ultralight as a dependency
    • Progressed on ephemeral headers implementation

  • Update on Samba by Meld

    • Implemented new endpoints but facing delays with UTP library (putContent issue) and accumulator integration
    • Restructuring code for better modularity to integrate with Besu client
      • Need further exploration on the primary use case of Samba by the Besu client (eg. JSON-RPC serviing vs full block sync)

  • Update on Shisui by Qi Zhou

    • Added support for protocol versioning and decline/ accept code implementation
    • Fixed race condition bug, and merged ping extension PR
    • Investigating the whoareyou challenge response issue and performance bottlenecks in Go implementation

2. Discussion topics

2.1 Protocol Versioning Implementation

  • Most of the client teams have started implementing the protocol versioning
  • Teams are encouraged to implement miniimal versioning to enable incremental updates and compatibility testing

2.2 Ephemeral Headers Spec Update

  • The problem
    • The initial assumption that all EL headers could be sourced from LightClientUpdates was invalidated as the CL derives tx/ withdrawal data via SSZ instead of RLP/ MPT
  • The spec is being updated to
    • Clarify limitation: EL headers can’t be fully sourced from the Beacon Network
    • Define handling
      • Headers should be organized chronologically in payloads
      • Clients should retain headers during reorgs until chain validity is re-verified
      • Avoid unnecessary network requests that could case DDOS issue
      • Allow headers to propagate naturally across the network
    • Edge cases: Notes added for scenarios like reorgs and data propagation
  • Next step
    • Team working on the implementation is encouraged to read the PR link for details
  • Relevant github issue/ PR

2.3 Shisui & Ultralight Connectivity Issue

  • The problem
    • Milos obversed intermittent failures when sending Find_Nodes request to Shisui and Ultralight nodes
  • Pattern of failure
    • Find_Nodes requests fail at non-zero distance
    • Requests with zero distance or simple ping work fine
    • The issue isn’t consistently reproducible but happens frequently
  • Investigation
    • Initial debugging attempts suggest the session or message keys might be incorrect
    • Equivalent Hive tests are passing, ruling out protocol-level bugs
    • Shisui identified a potential race condition in node assignment logic and a fix has been proposed & under review
  • Next step
    • Team agree to collaborate via a live debug session, with Shisui deploying a test node for targeted troubleshooting
  • Relevant link

2.4 EIP-4444 Coordination Updates

  • Sepolia testnet: The initial May 1st drop date is now Sepolia testnet drop date, with efforts underway to align an EL client version ready for Sepolia so CL clients can test against
  • Mainnet drop date: The mainnet drop date is postponed to sync with Pectra upgrade, due to CL’s dependency on pre-merge logs

2.5 State Network Progress

  • State network rollout has stalled due to
    • Gossip performance issue: Bottlenecks in propagating new state data across the network
    • Dependencies: Protocol versioning, accept codes must be finalized first to unblock state sync features
  • Action plan
    • Short-term goal: Focus on shipping a client version that can sync state even if it’s slighly behind the head of the chain
    • Priority:
      • History network will take precedence over the State network due to higher urgency
      • Ephemeral state work and performance optimizations may follow later, depending on team availability
  • Team bandwidth constraints
    • There will be reduced manpower on Trin side during summer due to vacation/ parental leave
    • Potentially exploring collaboration with Fluffy team on the State network development

2.6 Hive test status

  • Two key failures remain unsolved
    • JSON-RPC extension: Some clients still need to expose required extensions via JSON-RPC
    • Post-merge proof validation: Minor bug persist in validating post-merge proof formats
  • Next step
    • Teams are urged to prioritize these fixes within the next two weeks to get Hive tests fully green, as prolonged failures risk being overlooked