Skip to main content

Consensus Quarterly Update

· 3 min read
Damian Nadales
Damian Nadales
Consensus Team Lead

Consensus Quarterly Update​

2023-01 - 2023-03​

Main achievements​

UTxO HD​

  • We finished the testing activities for the prototype, which involved adding new tests, and fixing and enabling temporarily disabled tests.
  • We spent a substantial amount of effort refactoring and cleaning the prototype.
  • We audited the UTxO HD prototype to make sure it can accommodate the migration of other tables (eg stake-keys registration) from memory to disk. The result of the audit was positive.
  • We ran ad-hoc benchmarks for reading keys and flushing values to disk. No unexpected costs found.
  • We ran the first system level benchmarks. The performance regressions reported were due to an unrealistic snapshotting rate. We need to re-run them again after we design a more fine grained locking mechanism.

Genesis​

  • We elaborated a roadmap of the remaining work for Genesis.
  • We presented the design to the IOG Researchers and PNSol on February 20. The design was well received. We updated the Genesis design with the researcher's feedback.
    • We plugged the new DoS vector identified during the aforementioned presentation.
  • We developed a generator for adversarial leader schedules that satisfy key Ouroboros properties, which will be used to test the Genesis design.
    • The generator enables use of smaller Ouroboros parameters, which makes extrema more likely and counterxamples easier interpret.
  • We wrote up the latest design iteration.
  • We continued benchmarking the Chain Sync Jumping prototype. In particular:
    • We debugged the prototype's performance regression, and unmasked the actual cause by patching our initial theory (bad queuing behavior)
    • We identified and validated the actual cause (a pathological case in BlockFetch tiebreaker).

Support​

  • We created two new tools. One for dumping CBOR encoded blocks to JSON. Ahother to serve a local immutable DB.

Conway era​

  • We integrated the Conway era into consensus.

Technical debt​

  • We fixed a bug with followers, which was discovered by property tests.
  • We developed a DSL for specifying and running ChainDB test cases.
  • We fixed failing tests with iterators.
  • We created micro-benchmarks for adding transactions to the mempool.

Fostering collaboration​

  • We released a new technical documentation site for consensus.
  • We factored out several packages to external repositories. Some of this work originated in the UTxO HD workstream.

Next steps​

UTxO HD​

Genesis​

Support​

  • Design Consensus side of hardfork-enactment in the Voltaire phase (#4180).
  • Estimate the number of file descriptors Consensus needs #20.

Tech debt​

  • Identify Quantitative Timeliness Agreements (QTAs) metrics that we can define for consensus. Pick one and implement benchmarks for it.

Fostering collaboration​

  • Onboard a new team member.