Choose retention around the actual retry window
Idempotency records consume storage, but deleting them too soon weakens replay protection. Base retention on client behaviour and downstream guarantees.
Read articleCobnex blogs / Australia
Cobnex blog
AI implementation, software architecture, cloud operations and Australian technology policy.
100 articles in Software architecture
Page 5 of 6
Include the cost of supporting older clients
Compatibility work extends beyond one adapter. Tests, documentation, data mappings and support all continue while an older contract remains active.
Read articlePrice the manual exception path in a saga
Rare partial failures can require substantial investigation. Include reconciliation and operator capacity when comparing distributed workflow designs.
Read articleEstimate isolation across shared and dedicated resources
Shared infrastructure can improve utilisation, while dedicated resources can simplify some boundaries. Compare the complete operating model rather than only the database bill.
Read articleHistorical schemas have an operating cost
Keeping old events readable requires more than storing schema files. Budget for replay, translation, tests and the people who maintain their meaning.
Read articleSize a cache for misses as well as hits
Memory is only one part of the budget. Source capacity, refresh concurrency and recovery behaviour determine whether caching actually reduces operating pressure.
Read articleLeave room for the migration's temporary data
A table change can consume storage, I/O and replication capacity while both old and new representations exist. Estimate the peak, not only the final size.
Read articleA hot record can limit the whole workflow
More application instances do not remove contention on one shared resource. Measure where work serialises before adding capacity.
Read articleReview the exception to the module contract
The unusual path often reveals whether a boundary is real. Inspect administrative operations, imports and reports that reach beyond the public API.
Read articleAsk where the consumer records a duplicate
The outbox makes publication recoverable, which also makes repeated delivery possible. Review duplicate handling at the consumer's actual side-effect boundary.
Read articleReview the same key with a different amount
A duplicate check must distinguish a matching retry from conflicting reuse. Test a valid request whose material value changes while its key stays the same.
Read articleAsk whether the field's meaning changed
A schema diff can miss a breaking change when the type and name stay the same. Review units, defaults and interpretation with an older caller.
Read articleAsk what cannot actually be undone
Review each completed effect against the real correction the business can perform. A method named compensate does not prove the workflow can restore its prior state.
Read articleReview the administrative escape hatch
Privileged tools often bypass the normal tenant context. Inspect their authority, target selection and audit trail as carefully as the customer-facing API.
Read articleMissing and cleared fields are different operations
Optional data needs an explicit interpretation. An omitted field, a null value and an empty string should not accidentally trigger the same update.
Read articleReview the read that follows a successful write
Users expect to see the change they just saved. Check the whole response path before accepting a cache policy that can return the previous value immediately afterwards.
Read articleCheck the SQL the migration tool will actually execute
A short ORM change can generate a costly or incompatible database operation. Review the emitted SQL and its production consequences before approval.
Read articleA retry must repeat the decision, not only the last statement
When a transaction aborts, its earlier reads may no longer be valid. Recompute the protected operation and keep irreversible effects out of the retry block.
Read article