Network & Infrastructure / High Availability & Recovery Design
RTO as the critical path through a recovery dependency graph
Individual recovery tasks each fit their estimate, yet the complete service misses its deadline. Serial dependencies and approval or validation delays can dominate the overall restoration path.
Environment and inputs: Routed and clustered services; define failure ownership, fencing and application recovery requirements before testing. Diagnostic/design example; not tested on production equipment.
Collect the evidence
Map task prerequisites, owners, execution times and parallelizable steps from network restoration through application validation. Include credentials, DNS, data restore and endpoint cutover.
Explain the result
Recovery time is not the sum of optimistic component restart times or the slowest isolated task alone. The actual dependency graph determines which work can overlap and which must wait.
Plan the fix
Rehearse the complete workflow and optimize its measured critical path. Prepare required artifacts and access ahead of time rather than assuming they will be available after the same incident.
Check the result and rollback
Validate a business transaction within the objective and record each stage's actual duration. Revise the recovery commitment if the tested workflow cannot meet it without unsupported shortcuts.