1 Commits

Author	SHA1	Message	Date
Marc Schier	f358078b1c	[Client] Central channel manager: ref-counted shared channels, coalesced reconnect, IRetryBudget (#3288) (#3852) ... # Description Introduces a central `IClientChannelManager` that owns client-side transport channels with reference counting, sharing, coalesced reconnect, and asynchronous participant notification. Sessions, discovery clients, and registration clients targeting the same `ConfiguredEndpoint` (with the same reverse-connect identity) now share a single underlying `ITransportChannel`; reconnect is transparent to callers; and the previous `AttachChannel`/`DetachChannel` + `SessionReconnectHandler` patterns are obsoleted. ## What lands ### Core types (`Stack/Opc.Ua.Core/Stack/Client/`) - `ManagedChannelKey`, `ChannelState`, `ChannelStateChange`, `ParticipantReconnectResult` - `IReconnectParticipant`, `IManagedTransportChannel`, `IClientChannelManager` - `IChannelReconnectPolicy` + `ExponentialBackoffChannelReconnectPolicy` (default mirrors historical `SessionReconnectHandler`: 500 ms → 30 s exponential) - `IRetryBudget` + `RetryBudget` — shared retry deadline so the two-level retry no longer compounds multiplicatively - `ClientChannelManager` — single non-partial sealed class with SOLID-extracted internal types under `Stack/Opc.Ua.Core/Stack/Client/Channels/Internal/`: `ChannelEntry` (behind `IChannelEntryHost`), `ManagedTransportChannelLease`, `ClientChannel`, `ClientChannelManagerMetrics` (IMeter), `ClientChannelManagerCertRotation` (auto `ReconnectAllAsync` on `CertificateManager` rotation), `ClientChannelManagerDiagnostics` (ActivitySource + EventSource). Refcount, coalesced reconnect, and transparent faulted-entry recovery via `SwapFaultedEntryAsync` (swaps a lease's underlying entry on subsequent `ReconnectAsync` when the prior cycle Faulted/Closed, preserves participant, back-off via policy `GetDelay(SwapCount)`) ### Three-state lifecycle gate `Disconnected` → `TransportConnecting` / `TransportReconnecting` → `TransportConnectedSessionReactivating` → `Ready` (or `Faulted` / `Closed`). Only `Ready` releases the service-call gate; the manager bypasses the gate internally for participant `ActivateSession` traffic during reactivation via an `AsyncLocal` scope. ### Session integration (`Libraries/Opc.Ua.Client/Session/`) - New `Session.CreateAsync(IClientChannelManager, …)` overload - `Session` implements `IReconnectParticipant`; reactivation handler distinguishes `Reactivated` / `RequiresSessionRecreate` / `TransientFailure` / `FatalForParticipant` / `FatalForChannel` - `Session.ReconnectAsync(ct)` automatically delegates to the channel manager when wired - `Session.RecreateInPlaceAsync` swaps managed-channel leases for failover-to-different-endpoint via a new atomic `IClientChannelManager.GetAsync(endpoint, participantFactory, …)` overload; same-key recreates delegate to manager reconnect; explicit-channel/connection callers retain legacy behavior - KA failure routes through `IClientChannelManager.ReconnectAsync(channel)` ### ManagedSession integration - `WithChannelManager(...)` builder + ctor param; DI-resolved automatically - Two-level retry: channel-mgr handles transparent reconnect; outer `ConnectionStateMachine` + `IReconnectPolicy` only triggers on terminal channel `Faulted`. Outer-state churn suppressed during channel-mgr cycles via `_channelReconnectInProgress` flag wired through `IManagedTransportChannel.StateChanged` - New `ManagedSession.ChannelStateChanged` event surfaces transparent reconnects - `ConnectionStateChangedEventArgs.UnderlyingChannelState` populated when outer reconnect was triggered by a channel fault - Shared `IRetryBudget` propagated so the layers enforce a single max-total-time ### Discovery / Registration / GDS Channel-manager-aware `CreateAsync` overloads on `DiscoveryClient`, `RegistrationClient`, `ServerPushConfigurationClient`, `LocalDiscoveryServerClient`, `GlobalDiscoveryServerClient`. Each registers a minimal `IReconnectParticipant`; co-located sessions and discovery probes targeting the same endpoint share a channel. ### HTTPS transport (`Stack/Opc.Ua.Bindings.Https/`) - New `IOpcUaHttpClientFactory` abstraction - HTTPS / OPC-HTTPS channels migrated to `IHttpClientFactory` + `Microsoft.Extensions.Http.Resilience` (10.6.0; AOT-compatible on net10 via source generators; legacy direct-HTTP path retained for older TFMs / no-DI consumers) ### DI `AddOpcUa().AddClient(...)` registers `IClientChannelManager` and the named HTTPS `HttpClient` + standard resilience handler automatically. `ManagedSessionBuilder` resolves the manager from DI when present. ### Obsoletions (functional, `[Obsolete]` with guidance) - `IClientBase.AttachChannel` / `DetachChannel` - `SessionReconnectHandler` - `SessionExtensions.ReconnectAsync(connection, ct)` and `(channel, ct)` legacy overloads ### Tests - Core: `ClientChannelManagerManagedTests`, `ClientChannelManagerCertRotationTests`, `RetryBudgetTests`, `OpcUaHttpClientFactoryTests` — **56 / 56 pass** - Client: `ManagedSession*Tests` updated; legacy `SessionReconnectHandlerTests` + `SessionExtensionsTests` preserved with `#pragma warning disable CS0618` — **129 / 129 pass** - Sessions integration: `ChannelManagerSharing` / `TransparentReconnect` / `SessionLifecycle` / `CertRotation` — **7 pass, 1 skipped** (`ChannelManagerExhaustionEscalatesAndRecoversWhenServerReturns` un-`[Ignore]`d and implemented in this PR via `SwapFaultedEntryAsync`; remaining skip is end-to-end `RequiresSessionRecreate` plumbing — carry-forward) - Stress (consolidated `Tests/Opc.Ua.Stress.Tests/Subscriptions/` + `Channels/`): chaos / contract / soak / lifecycle / leak-accuracy / gap / participant-result-aggregation tests merged from the previously-separate `Opc.Ua.Channels.Stress.Tests` project; nightly run via `.github/workflows/stress-test.yml` Builds clean (0 warnings / 0 errors) across all six TFMs: `net472`, `net48`, `netstandard2.1`, `net8.0`, `net9.0`, `net10.0`. ### Docs - `Docs/Sessions.md` new § 4 documents the channel manager, three-state gating, two-level retry with shared `IRetryBudget`, HTTPS resilience layering - `Docs/MigrationGuide.md` migration recipes for the four obsoleted API groups - `Docs/DependencyInjection.md` channel-manager and HTTPS factory registration ## Carry-forward (separate PRs) - End-to-end `ParticipantReconnectResult.RequiresSessionRecreate` → `Session.RecreateAsync` lifecycle wiring (currently incomplete — flagged in the 1 remaining skipped integration test) ## Related Issues - Fixes #3288 - Builds on #3282 (PR that introduced the initial `ITransportChannelManager` skeleton) ## Checklist - [x] 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. - [x] 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. *(Channel-manager-specific tests + ManagedSession/client tests verified across all 6 TFMs; full UA.slnx run is pending CI.)* - [ ] I fixed **all** failing and flaky tests in the CI pipelines and **all** CodeQL warnings. - [ ] I have addressed **all** PR feedback received.	2026-06-13 16:34:48 +02:00