iamHrithikRaj Distributed systems debugging
Define the invariant
State the property that should always hold, such as:
- An acknowledged write remains durable.
- A request is applied at most once.
- Failover does not expose stale ownership.
- Recovery converges without operator intervention.
Describe the observed counterexample precisely.
Map the flow
Identify:
- State owners and durable stores.
- Control-plane and data-plane paths.
- Synchronous and asynchronous boundaries.
- Retry, timeout, cancellation, and failover behavior.
- Replication, quorum, ordering, and consistency assumptions.
Build an evidence table
For each signal capture:
- Timestamp and clock source.
- Component and correlation identifier.
- Observation.
- Reliability and possible ambiguity.
- Hypotheses supported or contradicted.
Test hypotheses
- Rank hypotheses by explanatory power, not familiarity.
- Design tests that distinguish between leading hypotheses.
- Check duplicate delivery, late completion, stale reads, reordered events, partial persistence, and split ownership.
- Consider whether local success can hide global failure.
Recommend changes
- Restore the invariant at the narrowest responsible boundary.
- Make retries and recovery explicit and observable.
- Avoid adding coordination unless the invariant requires it.
- Include telemetry and regression coverage needed to detect recurrence.