High-level Summary​

This week the team shipped hydra-node 2.1.0 - a significant release that brings improved deposit security, the new SQLite-backed event store, a ~7% reduction in snapshot confirmation latency, and compatibility with cardano-node protocol version 12+. We encourage all operators to upgrade. Alongside the release, work continues on two long-standing items: partial fanout and a user-friendly configuration file for hydra-node to replace the current sprawl of command-line flags.

What did the team achieve?​

• Released hydra-node 2.1.0, which includes improved deposit security, the SQLite-backed event store, a ~7% reduction in snapshot confirmation latency, and compatibility with cardano-node protocol version 12+ release 2.1.0
• Upgraded to cardano-api 11.1 / cardano-node 11.0.1 to support protocol version 12+ #2607
• Switched from a lazy to a strict Map to reduce memory pressure during transaction processing #2599

What's next?​

• Continue work on partial fanout — choosing the UTxO set to fan out and final code review #2593, #2324, #2573
• Reduce disk usage in hydra-node #2601, #2600
• Investigate a node observing/persisting deposit events from unrelated Heads #2606
• User-friendly hydra-node configuration via config file #2581
• Accept PaymentExtendedKey (HD wallet keys) #2583

High level summary​

• CIP-118 - Nested Transactions:

  Over the past two weeks the Ledger team has continued to push the Dijkstra era forward on multiple fronts. The CDDL specification of block was updated to match CIP-0176 - Non-segregated Block Body Serialization, a dedicated block_body was added and an EncCBORGroup instance for DijkstraBlockBody was added to unblock downstream integration in Consensus. Serialization for DijkstraTx was fixed up as well. We also followed up on the Plutus context performance work introduced in the previous update by integrating StAnnTx (the state annotated transaction representation that memoizes the Plutus parts of validation) into the LEDGER, UTXOW, UTXO and MEMPOOL rules across every era. With this integration the performance benefits of the earlier memoization work are now realized end to end. Further work in this area will let us rip the benefits of this optimization upon block construction as well, not just during initial validation. On top of that, several guards were added to the Plutus V1-V3 context translation so that any of the new Dijkstra features that those older language versions cannot represent (subtransactions, direct deposits, balance intervals, etc.) cause translation to fail explicitly rather than silently producing a wrong context. We also did preparation work for running conformance tests in Dijkstra and started reorganizing the test hierarchy around a new class-based ImpSpec approach that enforces a common set of tests across all eras.

• LedgerHD

  The streaming infrastructure for injecting large amounts of data from genesis files, which was started in the previous cycle, has been completed. It now covers stake pools and the remaining state needed for the testing and benchmarking work that targets reading data in constant memory from disk and paves the way for further direct injection into on-disk ledger state.

• CIP-165 - Canonical Ledger State:

  The expansion of the Canonical Ledger State continued with two more namespaces being added under the new namespace-based query interface, entities/dreps/v0 and entities/stake_pools/vrf_key_hashes/v0.

• Maintenance

  We've expanded examples and added golden tests for all of the migrated queries from Consensus to Ledger done last cycle. Furthermore we did the same for transaction examples. All of this effort not only will let us remove golden tests unrelated to the Consensus component from the ouroboros-consensus repository, but also improve their quality.

  In addition to features we published the changelog for the recent cardano-node-11.0 release, made ZeroTreasuryWithdrawals a permanent governance check for every era starting with Conway, instead of not having it in the bootstrap phase. We switched ChainData and Attributes to use ByteArray instead of ByteString to avoid pinned-memory fragmentation. A few NoThunks instances were tightened up where consensus needs them for storing on disk and relaxed where the values are already forced to normal form. Finally, we fixed a cuddle failure on Plutus Constr data and a bug in its definition in the CDDL spec discovered by our new generator-based tooling.

Low level summary​

Features​

• PR-5787 - Remove redundant import
• PR-5785 - Relax header protocol version for testnets
• PR-5786 - Changelog for cardano-node-11.0
• PR-5733 - Dijkstra era CDDL for block, add block_body
• PR-5789 - Integrate StAnnTx in rules across all eras
• PR-5777 - Full support of data injection from genesis files using streaming
• PR-5793 - Change DijkstraTx decoder to support variable length encoding
• PR-5669 - Fail PlutusV1-V3 translation for non-empty subTransactionsTxBody
• PR-5797 - Make ZeroTreasuryWithdrawals a permanent check in gov state transation rule
• PR-5700 - Add entities/dreps/v0 namespace
• PR-5808 - Relax NoThunks instance for BlockTransitionError
• PR-5781 - Fail Plutus V1-V3 translation with guards
• PR-5813 - Implement EncCBORGroup instance for DijkstraBlockBody
• PR-5812 - Switch ChainData and Attributes to use ByteArray
• PR-5811 - Fix TranslateErainstance for DijkstraEra CertState
• PR-5743 - Add entities/stake_pools/vrf_key_hashes/v0 namespace
• PR-5823 - Add NoThunks instances for ChainTransitionError and ChainPredicateFailure
• PR-5816 - Import Rules as qualified
• PR-5799 - Add example transaction golden test for each era

Testing​

• PR-5778 - Add golden tests for queryConstitution
• PR-5761 - Expand upon transaction examples by adding missing fields.
• PR-5794 - Add golden tests for the rest of the query result types
• PR-5801 - Fix failing cuddle test for Plutus data Constr.
• PR-5775 - Preparation for conformance testing in Dijkstra
• PR-5803 - Start to re-organize test hierarchy: ImpSpec
• PR-5826 - Fix trace construction in TestChain

Infrastructure and releasing​

• PR-5790 - Bump slackapi/slack-github-action from 3.0.2 to 3.0.3 in the actions group
• PR-5796 - Disable doctest to unblock master
• PR-5806 - Bump cuddle to 1.7.0.0
• PR-5817 - Bump urllib3 from 2.6.3 to 2.7.0 in /doc
• PR-5822 - Remove weird hyperlinked space between badges
• PR-5758 - Refactor testing in GitHub CI

High level overview​

This week, the Mithril team completed the trusted setup validation for the SNARK circuit in the STM library, the implementation of standard Schnorr signatures in the STM library, the implementation of the SNARK-friendly protocol message, the in-circuit and off-circuit verification tests for the recursive SNARK circuit prototype, the preparation of the recursive circuit refactoring, and the preparation of the prover input implementation in the STM library.

The team also prepared the ledger state certification proof of concept and continued work on enforcing the DMQ message ID format.

Finally, they completed the upgrade to Cardano node v.11.0, the update of all GitHub runners to Ubuntu 24.04, and continued work on robust support for unknown and in-progress signed entity types.

Low level overview​

Features​

• Completed the issue Trusted setup validation for SNARK circuit in STM #2944
• Completed the issue Implement support for Schnorr signatures in STM #3136
• Completed the issue Implement SNARK-friendly protocol message #3146
• Completed the issue Add in-circuit verification tests for recursive SNARK circuit prototype #3192
• Completed the issue Prepare Ledger State certification PoC #3242
• Worked on the issue Prepare the refactoring of the recursive circuit #3126
• Worked on the issue Prepare implementation of the prover input in STM #3137
• Worked on the issue Add off-circuit verification tests for recursive SNARK circuit prototype #3193
• Worked on the issue Enforcement of DMQ message id format #3251

Protocol maintenance​

• Completed the issue Upgrade to Cardano 11.0 #3257
• Completed the issue Update all GitHub runners to Ubuntu 24.04 #3246
• Completed the issue Rust doc.rs built targets breaking-change #3212
• Worked on the issue Robust support for unknown and in progress signed entity types #3172
• Worked on the issue Enforce Mithril crates versions in downstream Mithril crates #3245

High level summary​

The Plutus team recently published a blog blog post about the improved uplc command-line tool.

Among other things, the tool can optimize Plutus scripts. Experiments on recent mainnet scripts indicate execution-cost savings of more than 10% on average. So, if you are not already using it, it is worth checking what you may be leaving on the table.

Feedback, bug reports, and ideas for further improvements are very welcome. Please share them by opening issues in the Plutus repository on GitHub.

Further improvements to UPLC optimization have been made in recent weeks and are now integrated into the uplc tool. These include a new --inline-unconditional-growth flag for tuning the aggressiveness of the inliner, Agda certifiers for several optimization passes, a new UPLC constant-folding pass, and a pass that hoists polymorphic builtins to reduce the use of force. Common subexpression elimination (CSE) has also been improved.

Low level summary​

Key Pull Requests Merged​

• Make CSE see through bindings
• Add inline-unconditional-growth flag, controlling aggressiveness of unconditional inlining
• Remove PlutusTx.Plugin and plc; make injectAnchors optional for plinthc
• Certifier: fix the CSE translation relation and re-enable it
• Certifier for case-reduce
• Add uplc command line tool user guide
• Certifier for LetFloatOut pass
• Add detailed error message for unsupported casing on Integer
• Improve error reporting for a few unsupported types
• Add a constant folding pass to UPLC
• Add uplc command line tool user guide
• Print optimization report in uplc optimize
• [uplc] Use typical key order in optimized blueprint
• UPLC optimization pass: hoist polymorphic builtins

Overview of sprints 110, 111, 112 and 113.​

Summary​

Leios​

The mux egress prioritisation issue was resolved, delivering static priority-based scheduling for mini-protocols. Work on weighted fair queueing with token bucket support was concluded: it allows bursty protocols to send multiple SDUs back-to-back without starving other mini-protocols. However, right now we don't have evidence that the additional complexity is really needed to achive better performance. A TxSubmission V2 demo is being merged, and an alternative design without a central decision thread is being explored.

Ouroboros-Network​

Tx-submission v2 now returns results from submitTxToMempool, a prerequisite for DMQ-Node integration. The long-standing ChurnMode refactoring was merged, together with a property-based tx integrity test for cardano-diffusion. Nodes now warn about misconfigured local socket permissions (an issue identified by Claude LLM). A fix for initial syncing targets is under review, which will reduce load on bootstrap relays during node startup by setting lower active-peer targets before the first churn cycle.

DMQ-Node​

Versions 0.3.0.0 and 0.4.0.0 were released. The 0.4.0.0 release includes trace-dispatcher integration, Prometheus metrics, and CLI improvements. Work is ongoing on an announciness metric for peer selection — scoring peers by how often they are first to announce a valid signature — and on connecting the DMQ kernel to cardano-node.

Leios​

PR / Issue	Status	Sprint
TxSubmissionV2 demo	in review	112
tx-submission v2: undecision	in progress	112
network-mux: weighted fair queueing and token bucket for burst support	in progress	111
Mux: single peer performance for Leios	in progress	110
Mux egress prioritisation	resolved	110

Ouroboros-Network​

PR / Issue	Status	Sprint	Notes
tx-submission v2: return results in submitTxToMempool	merged	113
drop support for x86_64-darwin	merged	113	contribution by dermetfan
Local socket access right warnings	merged	113
connection-manager: added a comment	merged	113
Clarify LedgerPeersConsensusInterface	in review	113
Fix initial syncing targets	in review	113
Various small changes	in review	113
cardano-diffusion: tx integrity test	merged	112
ChurnMode refactored	merged	112
Code refactoring (burst engine)	merged	112	related to WFQ
Removed AcquireConnectionError	merged	111
Updated documentation	merged	111
new tracing: fixed Stateful.TraceRecvMsg	merged	110
LocalRootPeers - ToJSON instance	merged	110
Fixed peerselection test failure	merged	110
cardano ping implemented with ouroboros-network	blocked	110

DMQ-Node​

PR / Issue	Status	Sprint
announciness metric for peer selection	in progress	113
node kernel cleanup	in progress	113
Prometheus prefix	merged	111
Prometheus counters prefix	merged	111
CLI improvements	merged	111
dmq-node-0.4.0.0	merged	111
trace-dispatcher integration	merged	110
dmq-node-0.3.0.0 release	merged	110

IOSim​

PR / Issue	Status	Sprint
Remove withLiftST	merged	112
io-classes-1.10.1.0	merged	112
Add IOSimPOR QuickCheck monadic combinators	merged	110

Typed Protocols​

PR / Issue	Status	Sprint
support io-classes-1.10	merged	112

Contra Tracer​

PR / Issue	Status	Sprint
Contra.Tracer extra APIs	merged	110