4 Commits

Author SHA1 Message Date
romanett 28f1401324 Server: cut request-path lock contention and allocation; add load harness (#4707)
Profiling the reference server under load showed most request-path CPU
spent spinning on contended locks, plus several avoidable allocations
per request or per node. This PR removes them, switches the reference
server to Server GC, and adds the load harness used to measure it.

## Results

Paired A/B against `master` (3 alternating rounds, medians, 20 sessions,
workstation GC on both sides, 24-core machine):

| Scenario | Throughput | p50 | p90 | Server CPU / op | Server alloc /
op | Lock contention |
|---|---|---|---|---|---|---|
| Read, 1 value | **+45%** (94k → 137k req/s) | −20% | −46% | −37% |
−39% | −94% |
| Read, 100 values | **+40%** | −26% | −17% | −24% | −25% | +130% ¹ |
| Read, 100 values, SignAndEncrypt | **+48%** | −36% | −20% | −30% |
−26% | +106% ¹ |
| Browse (Server object) | **+33%** | −31% | −12% | −13% | −14% | −40% |
| Write, 100 values | +13% | −12% | −4% | −10% | −19% | −23% |
| Data-change subscriptions | ±0 ² | ≈ | ≈ | −14% | −17% | −29% |

¹ The faster server spends more time in the remaining per-node locks.
² Throughput is bounded by the writer rate in this scenario.

Separately, Server GC instead of workstation GC doubles Read-100
throughput (21k → 44k req/s) and cuts p90 from 2.1 ms to 0.6 ms, because
workstation GC paused the server for about half the wall time under
load. The working set grows from ~210 MB to ~430 MB.

## Changes

- **`ObjectPool<T>`**: lock-free slot array. `ConcurrentBag.Count` took
every per-thread lock on each `Return` of the pooled response value-task
source, once per request.
- **`FairRequestQueue`**:
- drops redundant gate entries: the fail-fast pre-checks and the stopped
check read volatile fields and are re-checked under the gate; the owner
count is folded into selection;
- coalesces wake pulses with a pending flag, so the bounded signal
channel's lock is only taken when no token is outstanding. Wake-count
semantics in the tests are unchanged.
- **`DefaultServerResourceIsolationProvider`**:
  - compares peer addresses without `GetAddressBytes()` allocations;
- builds the unsecured verification context only when a classifier is
configured.
- **TCP listener / channel**: caches the certificate DER copies per
channel, keyed on the certificate instance. `X509Certificate2.RawData`
returns a fresh copy on every access, and the listener read it for every
request.
- **`EndpointBase`**: resolves the request `ActivitySource` once instead
of `Assembly.GetCallingAssembly()` per request.
- **Node managers**:
- one `ServerSystemContext` copy per request (cached on the
`OperationContext`) for per-node callbacks: permission metadata, node
metadata, view membership, method lookup;
  - removes a discarded copy in `GetReferenceDescriptionAsync`;
- per-request operation caches are plain `Dictionary` instead of a
`ConcurrentDictionary` with 24 lock objects;
  - the validation cache is built in one pass;
  - fixes zero-capacity error lists.
- **`ResourceManager`**: translation lookups read an immutable snapshot
that is rebuilt after writes. Browse serialised on the global lock for
every display name.
- **`MonitoredItem`**: shares the default `DataChangeFilter` instead of
allocating one per sampled value.
- **Reference server**: `ServerGarbageCollection=true`; new "Garbage
collector mode" section in `docs/ServerScalability.md`.
- **`perf/`**: `ServerLoadHarness` (out-of-process server plus load
driver, server-side CPU/GC/alloc/contention deltas, optional
`dotnet-trace` capture), `TraceAnalyzer` (TraceEvent-based
CPU/allocation/contention aggregation), and paired A/B scripts. Not part
of `UA.slnx`.

### Behaviour notes for custom node managers
- The `IDictionary<NodeId, NodeState>` operation cache handed to
overrides is now a `Dictionary`. It was a `ConcurrentDictionary`, but
only one request flow uses it.
- Within one request, per-node callbacks of a node manager share one
`ServerSystemContext` copy.

### Later commits on this PR
- **Permission checks without `NodeMetadata`** (`9068684c3`): the
role-permission and access-restriction validators run on an internal
`PermissionMetadata` struct; `AsyncCustomNodeManager` fills it on the
stack from the same attributes and namespace defaults. Browse's
reference filter reads 3 attributes per target instead of 13. Read 100
values: 120.6 → 95.7 KB/request, ~21k → 26k req/s; Browse 67.6 → 51.8
KB, 26.7k → 29.8k req/s.
- **Read-only channel evidence** (`936b28d76`, `dc638ab9f`):
`SecureChannelContext.ClientChannelCertificate`,
`ServerChannelCertificate` and `ChannelThumbprint` are `ByteString`, so
the cached per-channel certificate buffer is shared without a copy and
cannot be altered by handlers or classifiers. **Public API change**, see
the new section in `docs/MigrationGuide.md`. The isolation provider's
revalidation snapshot still copies.
- **Session lookup** (`936b28d76`):
`SessionManager.TryGetSessionContext` takes the candidate snapshot
without the bindings lock; the validating check under the lock is
unchanged (2 instead of 4 global lock acquisitions per request).
- Unit tests for `ObjectPool`, the per-request system context cache, the
translation snapshot, `SecureChannelContext` null semantics and a
stopped `FairRequestQueue`; `perf/` follows the repository conventions.

## Testing
- `Opc.Ua.Server.Tests` (net10.0): 8386 passed before the `ByteString`
change. After it, 13 secure-session and isolation tests failed; both
causes are fixed in `dc638ab9f` and those tests (25 with their variants)
pass. A full rerun of the Server, Sessions, Core, Redundancy, LDS and
GDS suites on the final commit is in progress.
- Full solution builds for net10.0 and net48; `dotnet format whitespace`
clean.

### o6-automation opcua-benchmarks (sampling, deep pipelines)
Replicated both tests of the [o6-automation
benchmark](https://github.com/o6-automation/opcua-benchmarks) in the
harness (`--scenario counters`, and `read` with 10 clients × N
outstanding), paired against `origin/master`:

| Test | master | this PR |
|---|---|---|
| Subscription sampling, 100 Hz, every item ≥ 99 % of samples, 1 item |
FAIL (75–94 %) | PASS (100 %) |
| same, 1024 items | FAIL (64–73 %) | PASS (99.9 %) |
| same, capacity | — | between 4096 and 6144 items (~410–520k samples/s)
|
| Read, 10 clients × 100 outstanding, None | stalls (0–1.7k req/s) |
121–131k req/s |
| Read, 10 clients × 100 outstanding, SignAndEncrypt | stalls (0 req/s)
| 89–91k req/s |
| Read, 10 clients × 1000 outstanding | channels faulted
(`BadTcpNotEnoughResources`) | 0 errors, ~45–54k req/s |

- **Fixed-rate sampling** (`30b769d13`): the sampling loop waited one
interval after each sample, adding timer overshoot and sampling time to
every cycle; samples now have absolute deadlines.
- **Async response send** (`cdac5c5ca`): `SendResponse` blocked
thread-pool workers on the channel gate; with many requests in flight
the receive loop that was handed the gate waited for a pool thread and
the channel stalled. The TCP, Kestrel TCP and WebSocket listeners now
use `SendResponseAsync`.
- **Backpressure instead of channel fault** (`191cd2ba7`): server
channels stop reading while more than 100 responses are queued and
resume at 50, instead of faulting the channel. Client channels keep
reading. At 10,000 outstanding requests throughput is ~50k req/s with or
without the limit engaged, so the remaining gap to the 100-per-client
case is not the backpressure.

## Not changed
- `SentMessageQueue` deep-clones every `NotificationMessage`. Retained
messages return their pooled payloads on acknowledgement while the
response copy may still be queued for send, and a client can acknowledge
a sequence number before receiving it; the clone keeps a recycled
payload from reaching another session's response. Removing it needs a
send-completion hook from the transport.
- Generated responses allocate a default `ResponseHeader` that is
replaced (~2-3 % of per-request allocation). Fixing it means making
structure fields of every generated type lazily initialized, a
generator-wide change to default values, equality and encoding.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-09 13:00:49 +02:00
romanett 9b034f8291 Enable nullable reference types centrally; migrate all unset and annotations-only projects (#4700)
# Description

Nullable reference types are now enabled once, in `common.props`, and
every project in the repository builds warning-clean with them.

**Configuration**
- `<Nullable>enable</Nullable>` lives in `common.props`. All per-project
`<Nullable>` settings are removed: 178 project files (enable,
annotations, and the `disable` in the three Aot test projects).
- 419 per-file `#nullable enable`/`restore` directives and the 4
`#nullable disable` directives are removed.
- Kept on purpose:
- The 5 `<auto-generated>` schema files (`UANodeSet.cs`, `UA Type
Dictionary.cs`, `OPCBinarySchema.cs`, `SecuredApplication.cs`,
`PInvokeHelper.cs`) keep `#nullable enable`. The compiler ignores the
project setting in generated code, so the directive is required there.
- `tests/Opc.Ua.Interop.LegacyPeer` keeps `disable`. It builds against
the 1.5.378 packages and does not import the repository props.
- `docs/DeveloperGuide.md` and `.github/copilot-instructions.md` now
describe the central setting.

**Migration** (the 43 unset and 13 annotations-only projects, roughly
10k diagnostics)
- **Production code: annotated at the declarations.** Covers
`tools/Opc.Ua.SourceGeneration.Core`, `src/Opc.Ua.Lds.Server` and the
LDS sample.
- Members, parameters and returns are nullable where null actually
flows.
- Null-check helpers carry `[NotNullWhen]` (`IsNull`, `IsValidXmlName`,
`IsMethodTypeDesign`).
- `CoreUtils.Format`, `Utils.Format`, `ITemplateWriter.WriteLine` take
`params object?[]`. `Template.AddReplacement` takes `string?` (rendering
already skips null replacements).
- `IRegisteredServerStore.RegisterAsync` returns
`Task<RegistrationEntry?>`: it returns null when a registration is
removed.
- Dereferences backed by an invariant (for example, the validated model)
use `!`, so runtime behaviour is unchanged.
- **Behavioural changes in production code** (small, deliberate):
- `NodeSetToModelDesign` throws `InvalidOperationException` when the
file is not a NodeSet. Before, it threw a NullReferenceException on the
next line.
- `ModelDesignValidator` starts its lookup tables empty instead of null.
A redundant `if (m_nodes == null) return;` guard is gone.
- **Test code: minimal annotations.**
  - `?` on values that can be null, `!` where the test asserts non-null.
  - `= null!` for fixture members assigned in SetUp.
- `TryGetStructure<T>(out T? x)` where the inferred `T?` broke the
`IEncodeable` constraint.
- A few redundant `== null` checks on structs (`NodeId`, `ArrayOf<T>`)
folded into the adjacent `IsNull`/`Count` checks.

**Notes for reviewers**
- The diff is large (~1,500 files) but almost entirely mechanical: `?`,
`!` and directive removal. The non-annotation changes are listed above.
- Known follow-up, not done here:
`IModelDesign.Namespaces/TargetNamespace/NamespaceUris` stay
non-nullable even though the validator returns null before it loads a
dictionary. Making them nullable would ripple through every generator
call site.

## Related Issues

- Fixes #4439

## Checklist

- [ ] 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.

The "no new warnings" box covers net10.0 and net48: full non-incremental
builds of `UA.slnx`, `tools/SourceGeneration.slnx`,
`tools/MigrationAnalyzer.slnx` and the Aot test projects finished with 0
warnings and 0 errors under the repository's warnings-as-errors
settings. net9.0 and net8.0 also had no nullable diagnostics, but they
were not rebuilt after the final fixes. Tests have not been run locally
yet.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-08 08:48:13 +02:00
Copilot de3476d332 Remove HTTPS binding dependency from server packages (#4297)
# Description

`Opc.Ua.Server` and `Opc.Ua.Gds.Server.Common` depended directly on
`Opc.Ua.Bindings.Https`, which pulled ASP.NET Core into server
applications
even when optional HTTPS-based transports were not used.

- Remove the HTTPS binding project references from Server and GDS
entirely.
- Add a Core-owned `IOpcUaTransportBuilder` contract for builders that
support
  transport registration.
- Move the type-preserving HTTPS, WSS, Kestrel OPC TCP, and Web API
fluent
  extensions into `Opc.Ua.Bindings.Https`.
- Remove the repository-wide `NoHttps` / `NOHTTPS` build switch.
- Keep ConsoleReferenceServer HTTPS/WSS support through an explicit
binding
  reference and the ASP.NET Core container runtime.
- Document that applications must reference the optional binding package
  directly.

## Validation

- Built `Opc.Ua.Bindings.Https` in Release for all target frameworks.
- Built Server and GDS for .NET 10 and .NET Framework 4.8.
- Built ConsoleReferenceServer and PumpDeviceIntegrationServer for .NET
10.
- Passed 65 HTTPS binding dependency-injection tests.
- Passed focused Server and GDS transport-builder tests.
- Verified refreshed Server/GDS restore assets and output manifests
contain no
  `Opc.Ua.Bindings.Https` dependency.

## Related Issues

Fixes #4296

## Checklist

- [ ] 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.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce build or analyzer
warnings.
- [ ] I ran all tests locally using the `UA.slnx` solution against .NET
Framework and .NET 10.
- [ ] I fixed all failing and flaky tests in the CI pipelines and all
CodeQL warnings.
- [x] I have addressed all PR feedback received.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: marcschier <11168470+marcschier@users.noreply.github.com>
Co-authored-by: Marc Schier <mschier@microsoft.com>
Co-authored-by: romanett <7413710+romanett@users.noreply.github.com>
Copilot-Session: 41b98d43-8bb8-4587-8f3b-9532544dd582
2026-08-21 07:29:18 -07:00
Copilot d525bc3f28 Bound reconnect cleanup and organize samples by domain (#4276)
# Description

This PR fixes bounded ManagedSession reconnect cleanup and reorganizes
the sample applications into domain-focused folders.

## Reconnect cleanup

- Bounds reconnect integration cleanup with independent 30-second close
and dispose limits.
- Sends `CloseSession` through the awaited transport request path during
`Session.DisposeAsync`.
- Preserves explicit `Session.CloseAsync` behavior that waits for or
cancels outstanding publish requests.
- Covers the disposal request path with a regression test.

## Sample organization

- `samples/OpenUsd`: `GeneratorServer`, `SiteCompositionServer`
- `samples/Redundancy`: `RedundantClient`, `RedundantServer`,
`RedundantPubSub`
- `samples/Isa95`: `MinimalIsa95Server`
- `samples/MinimalApi`: `MinimalBoilerServer`, `MinimalCalcServer`,
`MinimalClient`
- `samples/DI`: `PumpDeviceIntegrationServer`
- `samples/Lds`: `ConsoleLdsServer`
- `samples/Reference`: `ConsoleReferenceClient`,
`ConsoleReferenceServer`
- `samples/PubSub`: `ConsoleReferencePubSubClient`

`UA.slnx` now exposes the same requested domain groups. Project
references, tests, runtime sample probes, CI workflows, Dockerfiles,
Compose files, helper scripts, and documentation were updated to the new
paths. `samples/Robotics/MinimalRobotServer` remains under `Robotics`.

## Validation

- `dotnet build UA.slnx`
- 3 Redundancy short-haul sample tests
- 70 DI sample tests
- 914 OpenUSD tests
- 1 WotCon model-materialization test
- 137 AOT tests
- `docker compose config` for all 6 moved Redundancy Compose files

## Related Issues

- Fixes #4273

## Checklist

- [ ] 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.
- [x] I built the complete `UA.slnx` solution locally.
- [ ] I ran all tests locally against at least .NET Framework and .NET
10.
- [ ] I fixed all failing and flaky tests in the CI pipelines and all
CodeQL warnings.
- [x] I have addressed all PR feedback received.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: marcschier <11168470+marcschier@users.noreply.github.com>
Co-authored-by: Marc Schier <mschier@microsoft.com>
Co-authored-by: Marc Schier <marcschier@users.noreply.github.com>
Copilot-Session: a2c2838f-74ae-4997-a1d4-50574d9e0636
2026-08-21 04:35:47 +00:00