Network Team Update

High-level overview of sprint 49 & sprint 50

Fixed PeerSelection bug

Karl Knutsson (Cardano Foundation (CF)) found a bug in the cardano-node-8.7.0 version used on the Sancho Net which was fixed in 8.7.1. It resulted in a node not being able to reconnect to an upstream peer once it was demoted by an asynchronous exception. This bug would be caught by Q&A in a mainet release, but for testnet releases, Q&A test suite is not used. We also developed a test which covers the bug in the ouroboros-network, we also identified a missing PeerSelection test which we need to port to our simulation network. See ouroboros-network#4734, ouroboros-network#4665.

Bootstrap Peers

Still under review, ouroboros-network#4555. The consensus team is now implementing the API we need for bootstrap peers. Once consensus API is implemented we will integrate changes in an experimental branch of cardano-node.

Tx-Submission

We started working on a new implementation of the tx-submission application. No tx-submission protocol changes are foreseen, but we want to be able to download each tx from just one upstream peer and share the results between different connections. We want to distribute the bandwidth between multiple clients. We also think that this work will prepare us for the future Ouroboros-Leios changes, which will contain various versions of tx-submission like mini-protocols. See ouroboros-network#4701.

Peer Sharing

Various fixes and improvements were implemented:

• ouroboros-network#4725

  • disabled peer sharing with initiator-only nodes: currently it's not possible to get peers from initiator-only nodes (edge nodes, e.g. wallets). In the future, we might change this, which will require running a server-side of the peer-sharing protocol by such nodes. See ouroboros-network#4726.
  • fixed peer-sharing codec
  • fixed a handshake bug which returned a wrong peer-sharing option

• ouroboros-network#4728

  • disabled peer-sharing for NodeToNodeV_11 and NodeToNodeV_12

• Karl Knutsson (CF) has been working on additional improvements, e.g. ouroboros-network#4735

With these fixes, Karl Knutsson (CF) was able to see that two peers on the mainnet can discover themselves through peer-sharing and keep being mutually useful and thus the connection surviving outbound-governor churn events.

IOSim

We improved the memory footprint of IOSim in io-sim#126, see ouroboros-network#4721 for heap profile improvements on large test cases.

We are working on optimising the memory footprint of IOSimPOR. We are reimplementing VectorClocks using a trie, instead of a map which leads to significant improvements.

Cardano-Ping

cardano-node-0.2.0.10 was released to CHaP, ouroboros-network#4746. This version exports more APIs which turned out to be useful in cardano-node test suite, see cardano-node#5536.

Technical Debt

We addressed some small tech-debt issues in ouroboros-network#4722:

• fixed some typos
• using bracket instead of onException in withSnocket
• improved haddocks
• organised TracePeerSelection constructors

We improved the memory footprint of some of our tests in ouroboros-network#4721.