3 posts tagged with "cross-simulation"

This week in Leios development, the team focused on simulation analysis, formal methods, and documentation updates. Key accomplishments include in-depth analysis of simulations at tag leios-2025w10, advancements in formal methods through a working trace verifier, and the development of technical reports.

Cross-simulation analysis​

• Completed a comprehensive analysis of simulations at tag leios-2025w10:
  • Analyzed Haskell simulation performance with and without CPU usage considerations
  • Varying key protocol parameters:
    • IB production rate
    • IB size
    • Length of Leios stages
  • Identified the following aspects of Leios:
    • Delay between IB generation and receipt at nodes
    • Peak and mean CPU usage over time
    • Breakdown of CPU usage by task type
    • Sizes of IBs, EBs, and RBs
    • Duplicate IB references in EBs
    • Reference to EBs from RBs
    • Resource utilization in network traffic.

Protocol and formal methods​

• Began developing a trace verifier in Agda:
  • Implemented event trace parsing using the Haskell module leios-trace-hs.

Documentation and research​

• Completed the full draft of the Leios technical report #1
• Created a skeletal draft of the Leios CIP
• Aligned with the latest CIP template
• Developed a detailed simulation analysis for the 100-node Leios network.

Programming and testing​

• Resolved several simulation issues:
  • #235: RB size does not reflect the presence of a certificate
  • #234: Fast transmission of large blocks at moderate IB rate
  • #232: Monotonicity of EB inclusion in RBs
  • #230: EBs are not large enough to include their IBs
  • #229: Rust simulations panics from overflow
• Enabled the visualization of network traffic and logging messages for multiple predefined 'scenarios' instead of a single hard-coded trace
• Updated the visualization to display resource utilization in network traffic.

Rust simulation visualization​

• Improved visualization capabilities:
  • Added support for multiple predefined 'scenarios' instead of single hard-coded trace
  • Moved the visualization logic to the client-side web worker for better performance
  • Added the visualization of per-node network traffic breakdown by message type
• Fixed critical simulation bugs:
  • Resolved issue #229 causing time travel and crashes in high-traffic high-latency scenarios.

This week in Leios development, the team focused on simulation analysis and formal methods. Key accomplishments include detailed analyses of both Haskell and Rust simulations, initial work on a protocol dashboard, and advancements in formal methods through trace verification in Agda.

Cross-simulation analysis​

• Completed a comprehensive analysis of simulations at tag leios-2025w09:
  • Refactored the ELT workflow to improve simulation data processing
  • Modified the Rust simulator to generate fixed-size input blocks (IBs) for comparison with Haskell
  • Partially resolved discrepancies in congestion metrics between simulators
  • Developed detailed analyses of:
    • IB generation to receipt elapsed time
    • Time-in-flight over node-to-node links
  • Identified the dual role of network bandwidth and CPU bottlenecks in high throughput congestion.

Protocol dashboard initiative​

• Initiated the design of an interactive protocol dashboard with planned features:
  • Protocol parameter configuration
  • Stake distribution settings
  • Performance visualization:
    • Block arrival efficiency
    • Transaction duplication
    • Leios operation rewards
    • Resource utilization
  • Security metrics visualization:
    • Quorum failure analysis
    • Certificate forgery detection
    • Adversarial block tracking.

Rust simulation​

• Enhanced parallel message handling capabilities:
  • Implemented parallel mini-protocol message transmission
  • Added even bandwidth distribution between mini-protocols
  • Introduced the simulate-transactions configuration option
  • Updated simulation output for better Haskell compatibility
  • Improved block visualization for scenarios with high IB counts.

Formal methods​

• Commenced trace verifier development in Agda:
  • Added decidability to Short Leios protocol relational specification
  • Implemented a proof-by-computation approach for execution traces
  • Applied the successful methodology from Streamlet formalization.

This week in Leios development, CPS-0018 for transaction throughput was approved, along with improved Docker support for simulations and analysis of cross-simulation results. The team also examined input block (IB) production rates and their impact on network performance.

Protocol development​

• CPS-0018 'Greater transaction throughput' officially approved:
  • Merged into Cardano Foundation's CIP/CPS repository
  • Documents urgency of higher transaction throughput
  • Defines goals for the Leios initiative
  • Identifies key open questions and use cases.

Cross-simulation analysis​

• Conducted a comprehensive analysis of IB production rates ranging from 1 IB/s to 100 IB/s:
  • Developed an ELT workflow for data processing via MongoDB
  • Created an R Jupyter notebook for analysis and visualization
  • Identified and addressed three significant bugs (#207, #208, #209)
• Key findings from the Haskell simulation:
  • Network congestion emerges at high IB production rates
  • Both average propagation time and slow propagation tail increase
  • A critical threshold of ~40 IBs/s was identified, beyond which network congestion severely impacts block reception
• Comparison of PeerNet and Haskell simulations:
  • Both exhibit qualitatively similar block propagation distributions
  • Both demonstrate protocol breakdown under high block production rates
  • Differences in resolution and configuration prevent exact comparison.

Infrastructure improvements​

• Added comprehensive Docker support for both simulations:
  • Optimized multi-stage Docker files for Haskell and Rust
  • Simplified deployment process
  • Enabled easy configuration via volume mounts and parameters
  • Documented usage in README.md.

Rust simulation​

• Enhanced Rust simulation capabilities:
  • Implemented bandwidth usage tracking
  • Added configurable bandwidth limits per connection
  • Fixed issues identified in cross-simulation comparisons
  • Started updating visualizations for improved clarity.

Haskell simulation​

• Enhanced IB sortition handling for IB/slot < 1
• Began integrating block expiration and diffusion-halt proposal
• Implemented ideal timing calculations for diffusion:
  • Added uniform block behavior configuration
  • Identified relay mini-protocol complexities:
    • Variable latency (3-4) for block transfer
    • Latency depends on traffic conditions and request handling.

Formal methods​

• Moved formal specification to a dedicated repository
• Established a conformance testing framework:
  • Enabled testing between Short Leios implementations
  • Documented the test suite execution process
• Initiated a survey of network models across IO consensus projects.