Durability preserves accepted operational information across process interruption. Recovery continues from preserved information without requiring the underlying fiscal operation to be executed again.
Durability Boundary
Operational information becomes relevant to recovery once it has been accepted into durable runtime state.
Durability preserves the information required to continue operational processing across process termination, restart or loss of transient execution context. It does not alter the fiscal state of the underlying document.
Preserved Information
| Information | Recovery purpose |
|---|---|
| Operation identity | Re-establishes the operation to which preserved information belongs |
| Subject reference | Maintains association with the applicable operational subject |
| Observed evidence | Preserves information already established through observation |
| Confirmed external reference | Retains an external reference when one has been established |
| Known operational condition | Represents the last condition supported by preserved information |
| Unresolved condition | Preserves the fact that available information is not yet sufficient to establish a conclusion |
| Contract/version context | Maintains the interpretation context applicable to preserved information |
The durability contract specifies the information that must remain recoverable, not the internal storage mechanism used to preserve it.
Recovery Semantics
Recovery reconstructs operational continuity from durable information after an interruption.
Recovery does not imply re-execution of the underlying fiscal operation. Preserved evidence and confirmed references remain the basis for determining what operational processing can safely continue.
Where preserved information is incomplete, recovery retains that incompleteness rather than replacing it with an assumed outcome.
Recovery Invariants
| Invariant | Observable guarantee |
|---|---|
| Preserved identity | Recovered information remains associated with the same operation |
| Evidence continuity | Evidence accepted before interruption remains available to subsequent processing |
| External-reference continuity | A confirmed external reference is not discarded by recovery |
| No inferred completion | Recovery does not convert incomplete evidence into a completed fiscal outcome |
| No fiscal re-execution requirement | Restoring operational continuity does not require the fiscal operation to be issued again |
| Repeat-safe continuation | Recovery may continue processing without implying repeated external fiscal effects |
Repeat-safe continuation is specified further in Chapter 10.
Incomplete Information
Recovery can restore only information that has been durably established.
If the preserved evidence does not establish the final condition of an operation, the recovered representation remains unresolved. Later evidence or reconciliation may establish additional information, but recovery itself does not infer the missing result.
Relationship with Idempotency
Durability determines what information survives interruption. Idempotency governs the guarantees that apply when processing resumes or previously observed information is encountered again.
The two properties are complementary: durable information provides continuity; idempotent processing prevents continuity from becoming unintended repetition.
Related Documentation
- 08. Runtime Observation — operational evidence, observation and incomplete information.
- 10. Idempotency & Processing Guarantees — repeat-safe processing and effect guarantees.
- 11. Failure Model & Isolation — interruption, failure boundaries and operational isolation.
- 12. Production Validation — production validation of durability and recovery behavior.