Files
Marc Schier b1c0cd20fd Fix classic browse-path subscription restoration (#4814)
# Description

Persisted classic subscriptions retain their server/client handles but
previously lost relative-path resolution metadata. Transfer could
succeed, yet a later `ApplyChangesAsync` attempted to resolve an
already-created item and failed. The SDK now owns this restoration
lifecycle without exposing a public resolution-state setter.

- Preserve the originally monitored target in internal snapshot state
and restore both `ResolvedNodeId` and `Status.NodeId`.
Transfer/reactivation use handles without re-browsing; fresh creation
resolves paths again.
- Version classic subscription/configuration files and read existing
unversioned 2.0 files using frozen legacy wire layouts. Legacy missing
targets remain unknown rather than being guessed.
- Exclude existing items from creation-time resolution, reserve creation
before asynchronous translation, and reject stale translation results.
Failed deletion retains identity and pending retry state.
- Support forward-only snapshot input using position tracking and
bounded, per-ExtensionObject buffering in the binary decoder, including
short reads. No whole-file buffering or reflection-based serialization
is introduced.
- Add unit/integration regressions and document the supported lifecycle
and migration implications.

**Compatibility:** Newly written files require the updated SDK. Existing
2.0 files remain readable. Assigning a different `StartNodeId` or
`RelativePath` to a created/in-flight item now immediately throws
`BadInvalidState`; unchanged assignments remain allowed. No V2
subscription-engine changes or 1.5 XML import are included.

## Checklist

_Put an `x` in the boxes that apply. You can complete these step by step
after opening the PR._

- [ ] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [ ] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.
2026-10-16 20:06:51 +02:00
..

Migrating from 1.5.378 to 2.0.x

Version 2.0 introduces a major architectural change from pre-generated code files to runtime source generation and more efficient memory use, with several major breaking changes requiring changes to your applications.

This folder includes all of the 1.5.378 → 2.0 migration content as a set of focused sub-documents so you can read only the parts that affect your application. Start with the Migration sub-doc index below to find the sub-doc that matches the symptom you are seeing.

Automate the migration. Add the OPCFoundation.NetStandard.Opc.Ua.MigrationAnalyzer analyzer package to your projects to receive analyzer warnings and one-click fixes for many of the patterns in these sub-docs. The package implements 26 analyzer rules through UA0030 (excluding UA0013, UA0016, UA0017, and the shim-only UA0029) across the index below and the cross-cutting guidance in the Migration Guide. UA0029 is currently a runtime-shim/manual marker surfaced through CS0618, not an analyzer. The type-safety subset (UA0002–UA0008, UA0014, UA0019) maps to types.md.

Pro TIP. Point your favorite coding agent at the opcua-v20-migration skill, which knows when to load each sub-doc and runs the codefixer for you.

Contents

Migration sub-doc index

Find the row that matches the error / API surface you are dealing with and read only the listed sub-doc. The agent skill uses the same table; loading a single sub-doc keeps the context window small.

When you hit… Read
CS0029 / CS1503 / CS0266 on NodeId, Variant, DataValue, ExtensionObject, QualifiedName, LocalizedText, ArrayOf<T> / MatrixOf<T>, ByteString, StatusCode, XmlElement, EnumValue; [Obsolete] warnings on built-in type APIs (analyzers UA0002–UA0008, UA0014, UA0019) types.md
Loggers (Utils.LogX, Utils.Trace), removed static logger helpers (Utils.SetLogger / Utils.SetLogLevel), telemetry context, constructor ITelemetryContext parameter changes, OLD-vs-NEW snippets, fluent DI registration (AddOpcUa().AddLogging().AddMetrics()), breaking-changes inventory, migration utilities telemetry.md
OPCFoundation.NetStandard.Opc.Ua.* package upgrade, TFM changes, Newtonsoft removal packages.md
Source-generated *Collection shims, NodeManager generator, default of boolean properties, project structure source-generation.md
IEncodeableFactoryBuilder, IType, JSON / XML / binary encoders, EncodeableFactory.GlobalFactory, IJsonEncodeable, ComplexTypes namespace move encoders.md
CustomNodeManager, NodeState clone / read / write helpers, OnAfterCreate(CancellationToken), FindChild / CreateChild NodeId assignment, INodeManager3, INodeCache.InvalidateNode, generics on BaseVariableState / BaseVariableTypeState, predefined-node processing, lock (node) on a NodeState, NodeBrowser.DataLock (analyzer UA0027) node-states.md
IUserIdentityTokenHandler, IClientIdentityProvider, IUserTokenAuthenticator, IAccessTokenProvider, ITokenIssuer, IIdentityClaims, caller-supplied secrets, secret store identity.md
CertificateValidator, ref-counted Certificate wrapper, CertificateManager, ICertificateProvider, obsoleted X509Certificate2 direct-exposure APIs, PushManagement transactions (ApplyChanges-gated TrustList updates), caller-owned CertificateStoreIdentifier.OpenStore stores, non-suppressible Bad_CertificateChainIncomplete certificates.md
ApplicationConfiguration changes, Data-Contract serializer removal, MinMetadataSamplingInterval → MinSupportedSamplingInterval, ParseExtension / UpdateExtension signature, session / browser state persistence configuration.md
Session → ManagedSession, V2 subscription engine, GDS-client Task → ValueTask modernisation, removed obsolete GDS APIs, durable subscriptions, PubSub, reverse-connect, server ISubscription publish-pipeline members / SessionPublishQueue internalized (analyzer UA0030) sessions-subscriptions.md
UaPubSubApplication.Create*, IUaPubSubConnection, UaPubSubConfigurator, IUaPublisher, AMQP transport, JsonEncodingMode.Reversible/NonReversible, PubSub JSON encoder changes, DataSetFieldContentMask RawData / timestamp behaviour pubsub.md
AlarmConditionState state-transition behaviour, auto-emitted GeneralModelChangeEvent, ModelChangeAggregator, INodeCache.InvalidateNode triggered by model change alarms-model-change.md
DateTime.UtcNow, Timer, deterministic time in tests; System.TimeProvider adoption timeprovider.md
ITransportListener.Open / Close removed, ReverseConnectManager.StartService / Dispose obsolete, reverse-connect DI/provider migration, custom ITransportListenerFactory / ITransportListenerCertificateRotation implementers need the new async method names transport-listener-async.md

All sub-documents

See also

  • Migration Guide landing page — index across all versions, including the small 1.05.377 → 1.05.378 and 1.04 → 1.05 legacy notes.
  • What's New in 2.0 — narrative tour of the 2.0 changes, grouped by theme and layer.
  • Profiles — facet / profile coverage of the 2.0 release.