stage 06 · Core
Systems Foundations
Trace state across processes and machines, bound concurrent work, recover durable data, and reason quantitatively about failure, reliability and trust.
7 sections 60 units about 230 h 0/60
Sections
In dependency order
- 1 Machine, Process, Memory & I/O Foundations 0/10
- 2 Concurrency, Scheduling & Bounded Work 0/9
- 3 Networks, Sockets & RPC Contracts 0/8
- 4 Databases, Transactions & Durable Storage 0/9
- 5 Distributed State, Replication & Streams 0/8
- 6 Observability, Reliability & Quantitative Design 0/9
- 7 Security, Privacy & Safe Evolution 0/7
Capstone
Systems Mechanisms & Failure Evidence Pack (10 to 14 h)
Use one small Linux repository and one evolving local service. The three artifacts prove mechanism fluency, bounded behavior and quantitative judgment without requiring a cloud platform, a production database or a consensus implementation.
Milestone deliverables
- Local mechanisms laboratory - process and signal trace, page and locality observations, file durability experiment, bounded queue, controlled concurrency failure, container resource-limit case, raw commands and reproducible measurements
- Fault-tested service slice - versioned framed RPC, request identity, deadlines, retries, cancellation, bounded admission, checksummed append-only state, crash recovery, one transaction or offset invariant and deterministic network, process and storage faults
- Systems evidence dossier - SQL and query-plan example, distributed history, SLO and capacity estimate versus load, telemetry-based incident, threat model, least-privilege tests, safe migration or rollback and one bounded private aggregate with guarantee limits
Rubric
| Criterion | Pass | Strong |
|---|---|---|
| Mechanisms laboratory | One command rebuilds every lab experiment and asserts its check, with raw output and environment kept for the process, page, durability, queue, concurrency and container cases. | Each timing claim names its oracle, pinning and repeats, and states what it did not test. |
| Fault-tested service slice | One command runs the service tests for framing, the fault matrix, deadlines, retries with idempotency, bounded admission with drain and crash recovery against the acknowledged-prefix oracle. | The restart case passes on durable state, and one randomly found schedule is kept as a regression. |
| Invariants under failure | The active-admin rule and the atomic effect-plus-offset rule each hold under injected failures, with a failing version kept beside each passing one. | The dossier states the failure model tested for each invariant and what lies outside it. |
| Distributed contract | The dossier history holds one permitted and one rejected case checked by the checker, with configuration IDs and fencing tokens recorded. | Every contract sentence points to the scenario that supports it. |
| Operations | The SLO, predicted and measured knees and capacity plan agree or explain their difference, and the incident keeps a timeline, recovery measures, postmortem and regression guard. | The capacity plan states what would shed or degrade under growth and why, with its arithmetic. |
| Trust and privacy | The dossier holds the threat model, privilege and tenant tests, migration drill and bounded private release with its limits, with passing tests. | Each residual-risk statement is specific enough for a reviewer to write the missing test. |
Capstone hours · 10 to 14
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