2 Commits

Author SHA1 Message Date
Marc Schier c4e0721a29 Add a documentation learning path and fix issues found while verifying it (#4555)
## Summary

### Documentation
- Stage the documentation index as a learning path: a first application,
independent client, server, and PubSub paths, then data and services,
companion models, production, advanced integration, and draft or
experimental capabilities.
- Add Getting started (repository samples or NuGet packages), OPC UA
concepts, Your first information model, and a production readiness
checklist.
- Add Native AOT application publishing, a first PubSub publisher and
subscriber exchange, and the UDP transport options.
- Add or expand contents navigation throughout `docs/`, and keep
contributor documentation separate.
- Correct outdated SDK examples and capability guidance, consolidate
repeated explanations into canonical guides, and repair local links and
heading structure.
- Rewrite What's New in 2.0 as a concise feature overview with short
linked details; keep migration instructions in the Migration Guide.
- Expand the feature catalogue with specification IDs, GDS, LDS, the OPC
10000-21 onboarding registrar, ISA-95, xRegistry, OpenUSD, and
sample-local models; distinguish draft status, explain crypto
pluggability, and bring performance guidance forward.
- Address review feedback on wording, active monitored items during
shadow reload, and the `Samples.md` filename and references.
- Regenerate the `opcua-v20-migration` plugin's bundled copy of the
migration guides so it matches the edited `docs/migrate/2.0.x` guides.
- Merge the latest `master`, preserving upstream resource-isolation
guidance within the task-based documentation index.
- Retain deferred Lingity findings where appropriate; this PR does not
claim that every document meets the Lingity score thresholds.

### Fixes found while verifying the guides
Each fix has regression tests that fail without it.
- **Client:** V2 subscriptions compared their lifetime with the
operation timeout instead of the session timeout, and logged a spurious
warning. `ISubscriptionEngineContext`, which is new in 2.0, gains a
`SessionTimeout` property; implementations must add it.
- **PubSub:** a subscriber now registers the `DataSetMetaData`
configured on its readers (OPC 10000-14 6.2.9.4), and the UADP decoder
decodes DataSetMessages that carry no ConfigurationVersion. Before, a
secured subscriber of the reference sample received no DataSets.
- **Source generator:** a ModelDesign method that declares its arguments
inline, without a method type, produced code that did not compile; it
now uses `MethodState`. The generated code of existing models is
unchanged.
- **MinimalClient sample:** waits for its first data-change notification
before it disconnects.

### Known issues, not addressed here
- UDP multicast: the publisher does not send on the interface that the
subscriber joins, and `MulticastLoopback` defaults to false. The PubSub
guide uses unicast for the exchange on one computer.
- The UDP metadata announcement is sent unsecured on secured writer
groups; a secured subscriber drops it with a warning.
- A server does not start in globalization-invariant mode, because
`ResourceManager` creates `CultureInfo("en-US")`. The Native AOT guide
cautions against the mode.

## Validation
- `git diff --check` and
`./.azurepipelines/validate-migration-plugin.ps1` (15 bundled migration
docs validated, plugin manifests synchronized).
- Local Markdown links, anchors, file-link casing, and contents lists
checked across all 87 documents under `docs/`. The index links every
top-level guide and every target of the previous index.
- Both Getting started routes, Your first information model, the PubSub
exchange, and the Native AOT publish of the Getting started client and
server were run as documented. The NuGet route and the tutorial use the
public `2.0.0-preview.5` packages.
- The changed libraries build for all target frameworks in Release
without warnings.
- Tests on .NET 10: Opc.Ua.SourceGeneration.Tests 199 passed;
Opc.Ua.SourceGeneration.Core.Tests 3,977 passed, 8 skipped;
Opc.Ua.Server.Tests `Fluent` category 621 passed; Opc.Ua.Client.Tests
subscription-engine tests 70 passed; Opc.Ua.PubSub.Tests 1,374 passed, 2
skipped; PubSub fuzz replay 145 passed. The new and affected tests also
pass on .NET Framework 4.8.
- Earlier merge validation: 174 resource-isolation tests passed on .NET
10.
- The full solution suite was not run locally.

Review and validation artifacts are maintained outside the repository.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-09-28 19:19:39 +00:00
Marc Schier 4633aa7a34 Harden HA address-space hydration and replica-consistent NodeIds (#4445)
# Description

Follow-up to #4390 for distributed address-space ownership,
authoritative
hydration, and replica-consistent wire NodeIds. Tracks #4444.

Identity implementation: `a78d59067` (Server policy/lifecycle/adapter
seam) and
`07faf5cfd` (replica identity module, runtime wiring, examples and
proofs).

## Replica identity

- `UseReplicaNodeIdentity` / `ReplicaNodeIdFactory` reserve fixed shared
namespace
indexes before node-manager construction and reuse
`DefaultNodeIdFactory`.
  ApplicationUri and built-in diagnostics/configuration remain local.
- Replicated startup requires an explicit identity contract. Namespace
layout,
  deterministic mode, replica-set identity and writer policy must agree.
Standard factory views, replacement and registration preserve the
policy.
- Active/passive writer-assigned identities are replicated unchanged.
Independent
creation requires stable keys or explicit IDs. Live IDs and retained
tombstones
are reserved before writer allocation; no network/storage call runs in
`New`.
- Protected store descriptors use strong routing, including customized
hybrid
prefixes. Unknown legacy state and empty eventual scans cannot authorize
  automatic adoption. Verified-new hybrid provisioning is explicit.
- Active/active frames compare the descriptor before CRDT merge.
Rejected frames
are not reported as applied; incompatible admission remains at
ServiceLevel 0
  through the standard service-level wiring.
- Shared metadata validation covers type definitions, data types,
references,
permissions, NodeId/ExpandedNodeId/QualifiedName values,
arrays/matrices,
  DataValues and encodeable structures/arguments, without reflection.
- Runtime preparation hydrates retained IDs before replacement routes
publish.
Rebinding keeps the existing store/election or gossip transport/map and
attaches
to the new node-manager sources. Normal node-manager mutations,
including
  AddNodes, reach the cached local-address-space adapter.
- WoT materialization retains the stable configured factory. Samples
expose
genuinely factory-created nodes and a client `--identity` failover
workflow.

## Preserved HA repairs

The published `d99995003` and `79da74f14` fixes remain in place:

- Shared linearizable sequence/lease coordination; no pretend CAS on
CRDT and no
  private counter substituted for shared coordination.
- Strict authoritative record decoding, protected pending reservations,
safe
  snapshot publication and required delta retention.
- Accepted topology state controls authoritative membership; stale
deletion
  cannot remove a newer incarnation.
- Independent subtree attachment tracking and correct disposal of the
final
  snapshot task.
- Values wait for their topology, and parent tombstone horizons prevent
older
  descendant values crossing incarnations.

A new deterministic regression also covers writer hydration preparation:
temporary reconciliation removals must remain inbound application, not
be
recaptured as new shared deletion records.

## Validation

### Review feedback fixes

`3a682155b` addresses the active-node notification, WoT namespace-index
bounds,
and retired-manager XML documentation feedback. The address-space
adapter now
notifies listeners with the registered active node, and both WoT
managers reject
missing/out-of-range namespace indexes before ownership is established.

Targeted feedback validation passes on net10.0 and net48: 8
address-space adapter
cases and 74 WoT cases per framework, plus 17
hydration/gossip/live-client
integration cases on net10.0. The wrong-instance notification and
missing
namespace regressions were reproduced before the fixes.

### Identity implementation evidence

| Selected scope | net10.0 | net48 |
| --- | --- | --- |
| HA repair, identity, metadata, peer admission and real-client
identity/reload fixtures | 215 passed | 215 passed |
| Factory, fluent authoring/import, NodeManagement and address-space
adapter fixtures | 213 passed | 213 passed |
| WoT node-manager fixtures | 68 passed | 68 passed |

- Real UA-TCP clients compare full NodeIds/reference targets across
independent
servers in all four deterministic modes, with different manager/creation
order
and local allocations. Saved IDs work after endpoint failover and
restart.
- Real AddNodes-created IDs remain readable through successive live
manager
replacements in both replication modes, including nodes created after a
reload.
- Two process-level cases start three sample replicas, kill the serving
process,
verify a different serving ServerArray URI, and reuse cached
factory-generated
  IDs for Read and CreateMonitoredItems without remapping or rebrowsing.
- The identity/hydration scenario runs from the actual published win-x64
NativeAOT
  executable in the existing historian companion host.
- The focused writer-recapture regression was observed failing without
its fix,
  then passing. The real reload scenario was additionally repeated while
  diagnosing that race.
- Changed-file formatting/style/analyzers were applied. Existing CA1508,
CA1823,
CA1861 and CA1850 warnings in untouched upstream files were not
suppressed.

The selected checks above do not replace full-solution CI, coverage
gates or
maintainer review, and do not claim that the entire solution or every
native
platform was run. #4444 remains the tracking issue.

## Contract and consistency limits

Fixed identity does not make eventual payload reads linearizable. Hybrid
views
remain non-destructive, use explicit tombstones, and do not infer
empty-store
bootstrap or partition completion from absence. Compacted snapshots
require
authoritative storage. Failed/uncertain reservations require
reconciliation.

There is no automatic namespace-slot allocation, persistent logical-key
mapping
database, live renumbering, legacy-store wipe/adoption, or new hash
algorithm.
Opaque shared structures require a registered codec so their
namespace-bearing
fields can be validated. Application callbacks are still
application-owned.

## Related issues

- Tracks #4444.
- Follow-up to #4390.
- Builds on the merged NodeId factory (#4433), configure/seal (#4442)
and
  lifecycle/import (#4427) integration at `aedd3f738`.

## Checklist

- [ ] I have signed the CLA and read CONTRIBUTING.
- [x] Added targeted regression and integration tests.
- [x] Updated directly related API, HA, migration and sample
documentation.
- [x] Ran scoped formatting and the targeted framework checks listed
above.
- [ ] Full UA.slnx matrix and coverage gates completed.
- [ ] All CI and maintainer review completed.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 9dbd9527-d818-47a0-984c-fbb1472d3d6b
2026-09-09 13:26:45 +02:00