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· One min read
Sebastian Nagel

High-level summary​

In between the end-of-year holidays, the Hydra team completed the implementation of the Conway support feature, fixed a minor bug that was hindering tests from running on MacOS, and addressed a regression in the protocol-parameter formats used by the hydra-node. They also worked on off-chain code for incremental decommits, specifically focusing on transaction creation. Furthermore, they conducted a spike on implementing a Chess game using Hydra, with an experience report provided.

What did the team achieve this week​

  • Fixed a regression on protocol-parameter formats used by the hydra-node #1226
  • Fixed a minor bug prohibiting tests running on MacOS #1218
  • Complete conway support feature #1227
  • Transaction creation off-chain code for incremental decommits #1218
  • First spike on implementing a Chess game on Hydra report, related to: #1098

What are the goals of next week​

  • Fully resolve protocol parameter misalignment #1234
  • Cut a release 0.15.0 to ship offline-mode and conway support
  • Prepare demo for conway support
  • Complete transaction creation and observation for incremental decommits
  • Backend for a hydra-explorer that can track all heads on-chain

· One min read
John Lotoski

High level summary​

During the lightly staffed holiday period for node SRE, the emphasis was on maintaining environment stability, tuning and resolving any noisey alerts.

Investigation into and testing around the following two topics also started during this period:

  • Ledger snapshots causing a small number of missed slots for forgers on mainnet: ouroboros-consensus-issue-868

  • A cardano-node rare file descriptor leak, with a more detailed description here

· One min read
Carlos LopezDeLara

2023-12-09 - 2023-12-30

High level summary​

  • Migrated reposotiries to IntersectMBO.
  • Improved era handling on cardano-api. Instead of enumerating every possible era, we use two constructors: 'CurrentEra' and 'UpcomingEra'. This design simplifies the handling of eras, especially for cardano-api consumers who are primarily concerned with the current mainnet era and the next era for an upcoming hardfork.
  • Cleaning-up the cardano-cli, in particular to the babbage era commands where some Conway options had spilled.

cardano-cli​

cardano-api​

cardano-node​

cardano-testnet​

docs​

CI & project maintenance​

· One min read
Sebastian Nagel

High-level summary​

This week, the Hydra team made significant progress, implementing an offline mode with associated refactoring. They enhanced user experience by detecting incompatible eras in hydra-node. Protocol changes were implemented for incremental decommits, addressing off-chain logic. Additionally, the team contributed fixes to cardano-ledger and coordinated with the Eternl team on enabling committing into a head from their wallet.

What did the team achieve this week​

  • Offline mode implementation #1118 and refactoring #1222
  • Detect incompatible era in hydra-node and provide better UX #1216
  • Implemented protocol changes for incremental decommits (off-chain logic) #1057
  • Contributed fixes to cardano-ledger#3949 and #3953
  • Synced up with the Eternl team on enabling committing into a head from their wallet

What are the goals of next week​

  • Maybe cut a release 0.15.0 to ship offline-mode and unsupported era UX
  • Full conway support in hydra-node
  • Transaction creation and observation for incremental decommits

· 2 min read
Marcin Szamotulski

High-level overview of sprint 51​

Outbound Governor Bug in cardano-node-8.7.2​

In the current sprint, we received a bunch of reports from SPOs about nodes not maintaining some connection when using cardano-node-8.7.2 (running in P2P mode). Such regressions are very important to us since they can lead to lost blocks. We were able to reproduce this issue. Every time there's a longer pause of block production (due to the statistical nature of Ouroboros), there is a chance that the bug will be armed. For this reason cardano-node-8.7.2 needs to be closely monitored.

We found the bug and developed a fix, ref. Karl Kntusson (CF) wasn't able to reproduce the bug with the patched version of the node for long enough (almost two weeks now) for us to belive that the fix is correct.

Advise for SPOs​

We created a release branch for 8.7.3. The advice from the network team is to either downgrade to the previous release, e.g. 8.1.2 or use the above release branch (note that there were no benchmarks made or Q&A tests yet).

Testing plans​

We were also able to reproduce the bug using IOSim, ouroboros-network#4757. However, the bug relies on a particular schedule of two threads which are involved and we needed to artificailly modify IOSim schedule in production code - something that we don't want to commit to the master branch. We also experimented with a randomised scheduler for IOSim, but that did not lead to finding the schedule which arms the bug: the search space grows exponentially with the number of steps in the threads, partial order reduction techniques implemented in IOSimPOR are more appropriate - unfortunatelly the simulation test is too large to be executed in IOSimPOR even with large amounts of RAM. To use IOSimPOR we need to implement a test which includes the two interacting components:

  • connection-manager
  • outbound-governor (where the bug was located)

which communicate through PeerStateActions, without including all the diffusion components as we do in our sim-net tests. More in style of outbound-governor tests where there is just a single outbound-governor, unlike in the sim-net which runs multiple communicating diffusions.

Bootstrap peers​

We continued working on bootstrap peers, ouroboros-network#4555

TxSubmission Decision Logic​

We continued working on tx-submission decision logic, ouroboros-network#3311