Examples
Examples
Try the starting example
- Services: ID, supplied nonnegative impact weight
- UI,5 API,3 DB,2 Cache,1
- Dependencies: dependent, dependency; or none
- UI,API API,DB Cache,DB
- Initially failed service IDs joined by |
- DB
- Potentially affected service IDs
- UI, API, DB, Cache
- Sum supplied affected-service weights
- 11
- Affected share of total supplied weight (%)
- 100
- Propagated affected services excluding initial failures
- UI, API, Cache
- One shortest dependency path from a failed service to each affected service
- UI: DB->API->UI; API: DB->API; DB: DB; Cache: DB->Cache
Try another scenario
- Services: ID, supplied nonnegative impact weight
- UI,5 API,3 DB,2 Cache,1
- Dependencies: dependent, dependency; or none
- UI,API API,DB Cache,DB
- Initially failed service IDs joined by |
- Cache
- Potentially affected service IDs
- Cache
- Sum supplied affected-service weights
- 1
- Affected share of total supplied weight (%)
- 9.090909
- Propagated affected services excluding initial failures
- None
- One shortest dependency path from a failed service to each affected service
- Cache: Cache
Calculation method
Calculation method
Potentially affected service IDs
Reverse-reachability from each initial failed dependency, assuming every supplied edge propagates failure.
Sum supplied affected-service weights
Sum supplied weights once per affected service.
Affected share of total supplied weight (%)
Affected weight/all service weights×100; undefined when all weights are zero.
Propagated affected services excluding initial failures
Affected services not explicitly selected as initial failures.
One shortest dependency path from a failed service to each affected service
For each node choose the shortest breadth-first path over reversed dependency edges, input-order ties.
Symbols and units
- a
- Services: ID, supplied nonnegative impact weight
- b
- Dependencies: dependent, dependency; or none
- c
- Initially failed service IDs joined by |
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- A conservative dependency-reachability scenario, not a measured outage prediction. Every edge is assumed failure-propagating; redundancy, degraded modes and likelihood are not inferred. No chaos experiment is executed.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
NIST: combinatorial testing and coverage measurement; audit rules are explicitly supplied ↗
Background reading; this does not imply endorsement or independent review of SumFizz.