# Lectures (Winter 2025 Term 2)

2026-10-08 · https://fsgeek.ca/teaching/cpsc-416-winter-2025-term-2/lectures/

Slides as used in class. Lectures 10 through 14 are the consensus series: it starts from single-decree Paxos and generalizes, using set-theory quorums so that _why_ quorum intersection works can be shown rather than asserted.

Date| Slides  
---|---  
2026-01-06| [Course framing, failure-first, GenAI and Goodhart](/media/2026/cpsc416-w25t2/L01-2026-01-06.pdf)  
2026-01-08| [Failure models, the network substrate, and evidence](/media/2026/cpsc416-w25t2/L02-2026-01-08.pdf)  
2026-01-13| [Time, ordering, and causality](/media/2026/cpsc416-w25t2/L03-2026-01-13.pdf)  
2026-01-15| [Global state: the problem](/media/2026/cpsc416-w25t2/L04-2026-01-15.pdf)  
2026-01-20| [Global state: the solution](/media/2026/cpsc416-w25t2/L05-2026-01-20.pdf)  
2026-01-22| [Single-node failure and recovery](/media/2026/cpsc416-w25t2/L06-2026-01-22.pdf)  
2026-01-27| [Two-phase commit (2PC)](/media/2026/cpsc416-w25t2/L07-2026-01-27.pdf)  
2026-01-29| [Coordinator failure and blocking](/media/2026/cpsc416-w25t2/L08-2026-01-29.pdf)  
2026-02-05| [From failure to consensus](/media/2026/cpsc416-w25t2/L10-2026-02-05-consensus.pdf)  
2026-02-10| [Walking the Paxos path](/media/2026/cpsc416-w25t2/L11-2026-02-10-paxos-walk.pdf)  
2026-02-12| [Breaking Paxos](/media/2026/cpsc416-w25t2/L12-2026-02-12-paxos-break.pdf)  
2026-02-24| [From Paxos to Multi-Paxos](/media/2026/cpsc416-w25t2/L13-2026-02-24-paxos-to-multi.pdf)  
2026-02-26| [Flexible Paxos](/media/2026/cpsc416-w25t2/L14-2026-02-26-flexible-paxos.pdf)  
2026-03-03| [Chain replication and CRAQ](/media/2026/cpsc416-w25t2/L15-2026-03-03-chain-replication.pdf)  
2026-03-05| [Consistency models and leaderless replication](/media/2026/cpsc416-w25t2/L16-2026-03-05-consistency-dynamo.pdf)  
2026-03-10| [Byzantine fault tolerance](/media/2026/cpsc416-w25t2/L17-2026-03-10-byzantine.pdf)  
2026-03-12| [The impossibility zoo](/media/2026/cpsc416-w25t2/L18-2026-03-12-impossibility-zoo.pdf)  
2026-03-17| [Geo-replication and Spanner](/media/2026/cpsc416-w25t2/L19-2026-03-17-geo-replication.pdf)  
2026-03-19| [Distributed transactions](/media/2026/cpsc416-w25t2/L20-2026-03-19-transactions.pdf)  
2026-03-24| [Adversarial protocol design](/media/2026/cpsc416-w25t2/L21-2026-03-24-adversarial-design.pdf)  
2026-03-26| [The failure model as political choice](/media/2026/cpsc416-w25t2/L22-2026-03-26-political-choice.pdf)  
2026-03-31| [CRDTs, and consensus in different clothes](/media/2026/cpsc416-w25t2/L23-2026-03-31-crdts-raft.pdf)  
2026-04-02| [Building a system that tells you it's lying](/media/2026/cpsc416-w25t2/L24-2026-04-02-self-reporting.pdf)  
  
Supporting material:

  * [Quorum diagrams (set-theory view of quorum intersection)](/media/2026/cpsc416-w25t2/quorum_diagrams.pdf)
  * [Evidence card (in-class template)](/media/2026/cpsc416-w25t2/evidence-card.pdf)