Reliability Advanced
Deadline & Isolation Simulator
Propagate deadlines, cancellation, bulkheads, and bounded fallbacks across dependency failure windows.
- Time
- 9-11 minutes
- Concept
- Deadline propagation and failure isolation
Backend concept
Circuit Breakers
Open, half-open, and closed states; timeouts, fallback behavior, failure classification, and dependency isolation.
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Key takeaway
Open, half-open, and closed states; timeouts, fallback behavior, failure classification, and dependency isolation. Start with the related games below when you want to turn the definition into practice.
Why this matters
Circuit breakers prevent one failing dependency from spreading latency and resource exhaustion across the system.
How to practice
Decide when to open, probe, close, retry, or serve a fallback.
0 active misses 0 reviewed 0 games completed
Local review for this concept
No local review items for this concept yet.
Learning objectives
- Allocate dependency budgets within an end-to-end deadline.
- Cancel abandoned work promptly.
- Isolate optional workloads and design bounded fallbacks.
- Choose when to open, half-open, and close a circuit breaker.
- Design fallbacks that preserve business correctness.
- Combine timeouts, bounded retries, jitter, and bulkheads to reduce blast radius.
Common mistakes to avoid
- Giving every hop the full client timeout.
- Ignoring client cancellation.
- Sharing one unbounded pool across workloads.
- Using very long timeouts that hold threads and amplify outages.
- Counting expected 4xx validation errors as dependency-health failures.
- Retrying without jitter, budgets, or idempotency.
Games for Circuit Breakers
Start with the first game, then use local review history to revisit missed decisions.
Reliability Intermediate
Circuit Breaker Clinic
Diagnose dependency failures and choose circuit breaker, timeout, fallback, retry, half-open, and bulkhead strategies that reduce blast radius.
- Time
- 6-9 minutes
- Concept
- Circuit breakers, timeouts, retries, fallbacks, and dependency isolation
Scaling Intermediate
Load Balancer Challenge
Route simulated traffic across backend servers using round robin, weighted round robin, least connections, and random strategies.
- Time
- 6-10 minutes
- Concept
- Load balancing strategies
Reliability Intermediate
Observability Incident Triage
Triage production incidents by choosing useful metrics, logs, traces, queue signals, database evidence, request ids, and alerting strategies.
- Time
- 6-9 minutes
- Concept
- Production observability, incident triage, metrics, logs, traces, and alerts