Task #127 / decision #144. The resilience infrastructure for per-PLC
circuit breakers is shipped and fully tested — the task description's
"current pipeline keys on DriverInstanceId only" was stale. The actual
state:
- `DriverResiliencePipelineBuilder` keys on
`(DriverInstanceId, HostName, DriverCapability)`.
- `CapabilityInvoker.ExecuteAsync` takes `hostName` per call.
- `IPerCallHostResolver` is the driver-side hook; AB CIP implements it.
- `PerCallHostResolverDispatchTests.DeadPlc_DoesNotOpenBreaker_For_HealthyPlc_With_Resolver`
proves the end-to-end isolation.
Remaining work is per-driver adoption, not shared infrastructure:
- AB CIP: live + tested
- Galaxy / FOCAS / OPC UA Client / AB Legacy: 1 device per instance by
design, trivially isolated
- Modbus / S7 / TwinCAT: single-device today; multi-device refactor is
per-driver surgery (Device row + options + resolver + transport
fan-out), not a shared-infra change
Shipping docs/v2/multi-host-dispatch.md as the canonical reference:
contract + driver-author checklist + current fleet-wide status table.
Future driver authors follow the AB CIP template.
No code change in this commit — doc-only.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
