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Network Q2 2023 Update

· 6 min read
Marcin Szamotulski

2023-04 - 2023-06

Main achievements

Eclipse Evasion

We finalised the design of eclipse evasion and implemented its mechanism which relays on connectivity to big ledger peers. Big ledger peers are the largest ledger peers which accumulate 90% of stake (currently there are less than 1000 of them). The outbound governor has new targets for known, established and active big ledger peers which work in a similar way that such targets work for ledger peers. The ouroboros-network#4662 PR is currently in review.

As part of this work we also identified a bug which would prevent a node to connect to itself. Such connections are not easily detectable and are expected to be dropped by the churn mechanism, nonetheless they should not be buggy. The failure was discovered thanks to our e2e simulation of diffusion using io-sim & property based testing.

The PR also refactors the heart of the ouroboros-network interface reducing technical debt that would otherwise accumulate.

We also identified a possible improvement in the churn mechanism, which will be implemented in Q3. Churn needs to await for peers to terminate, we can improve the synchronisation. [ouroboros-network#4617]

Ecosystem P2P Deployment Progress

We reached 50% of stake in hands of SPOs who run at least on P2P relay. Now also Emurgo and CF are running some P2P relays. Also 20% of IOG relays are running in P2P mode.

P2P Progress

Peer Sharing

We implemented bootstrapping for peer sharing (also known as light peer sharing). New downstream (inbound) peers are now added to the known peers of the outbound governor. Together with peer sharing this allows for non registered relays to propagate through the network. ouroboros-network#3596

Please note that peer sharing is disabled by default and is not considered safe until Bootstrap Peers (see below) or Genesis is implemented.

Diffusion (P2P)

  • We designed a feature which will reduce the load on IOG relays (in future also run by CF & Emurgo). The feature consists of two parts. A new source of peers called bootstrap peers (obtained from via an https request), the ability to switch from bootstrap peers to ledger peers if the node is synced (we are collaborating with the consensus team on the interface Bootstrap Peers IER). This feature will be completed in Q3. ouroboros-network#4530

  • We published a blog post about P2P design & implementation.

  • Karl Knutsson (CF) fixed an issue observed on a relay with a lot of outbound connections: ouroboros-network#4559.

  • We merged changes which allow the consensus layer to start / stop block forging thread. This will allow to deploy P2P block producing nodes which serve as a live backup node. ouroboros-consensus#140

  • We fixed a few bugs in local root peers DNS resolution service: ouroboros-network#4583, ouroboros-network#4571.

  • We limited concurrency of DNS name resolutions: ouroboros-network#4596.

  • Galois Inc implemented query option for Handshake: ouroboros-network#4256.

  • We fixed handshake query timeout: ouroboros-network#4608.

  • We implemented warm valency for local root peers. This can help when using DNS names in local root peers which resolve to many IP addresses. ouroboros-network#4575

  • We merged handshake changes which allow query protocol versions. Thanks to James Parker from Galois Inc.: ouroboros-network#4256, cardano-cli#30.

Other Improvements & Developments


  • We added node-to-node and node-to-client CDDL specs / tests for encoding of NodeToNodeVersionData and NodeToClientVersionData.

  • We clarified an inconsistency between CDDL spec and implementation which is highly polymorphic. We designed and implemented a fix for tx-submission and local-tx-submission mini-protocols. Specs for other mini-protocols will be improved at a later stage. ouroboros-network#4580

Cardano Ping


Typed Protocols

Cardano Client

  • We fixed a bug in cardano-client- release which results in clients (e.g. db-sync) negotiate an experimental protocol version.

Technical debt

CI improvements

GHC 9.4 & 9.6

We made all repositories under our control compile with ghc-9.4 and ghc-9.6 which includes ouroboros-network, io-sim, typed-protocols and Win32-network.

Next steps

We will continue towards our aspirational roadmap.

  • We will continue reviewing eclipse evasion.
  • As ouroboros-consensus#140 was merged, we are making progress towards releasing P2P on block production nodes. We hope to analyse performance regression on such nodes observed on the benchmarking cluster. roadmap-3887
  • We are also focused on roadmap-3969. Note that it was expanded in Q2.