ci: bound build and test concurrency

.github/workflows/v2-ci.yml

@@ -1,7 +1,6 @@
 # CI for the v2 branch — runs on every push + PR to the v2-akka-fuse / master
-# branches. Layered into two jobs:
-#   build           dotnet restore + build (fast feedback on compile errors)
-#   unit-tests      the WHOLE solution minus the env-gated tiers (self-maintaining)
+# branches. One job restores and builds once, then tests the WHOLE solution
+# minus the env-gated tiers (self-maintaining).
 #
 # Skips E2E (Category=E2E) and LiveIntegration (needs a real gateway/PLC/VPN) — both
 # are env-gated tiers with no hosted-runner fixtures. (The skip-gated *.IntegrationTests
@@ -20,38 +19,33 @@ on:
     branches: [v2-akka-fuse, master]
   workflow_dispatch: {}
 
+# #707: one active run per repository across push/PR triggers. Gitea 1.26 supports
+# workflow concurrency; newer pending runs can supersede an older pending run.
+concurrency:
+  group: lmxopcua-v2-ci
+  cancel-in-progress: false
+
 env:
   DOTNET_NOLOGO: "1"
   DOTNET_CLI_TELEMETRY_OPTOUT: "1"
 
 jobs:
 
-  build:
+  unit-tests:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-dotnet@v4
         with:
           dotnet-version: 10.0.x
-      # #606: code-reviews/README.md must be regenerated from the per-module findings.md
-      # files; --check exits non-zero on drift without writing (see REVIEW-PROCESS.md section 5).
+      # #606: regenerated review summary must remain in sync with module findings.
       - name: code-reviews README drift check
         run: python3 code-reviews/regen-readme.py --check
+      # #707: bound project workers and avoid concurrent NuGet restore work.
       - name: dotnet restore
-        run: dotnet restore ZB.MOM.WW.OtOpcUa.slnx
+        run: dotnet restore ZB.MOM.WW.OtOpcUa.slnx --disable-parallel -m:2
       - name: dotnet build
-        run: dotnet build ZB.MOM.WW.OtOpcUa.slnx --no-restore --configuration Release
-
-  unit-tests:
-    needs: build
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-dotnet@v4
-        with:
-          dotnet-version: 10.0.x
-      - name: dotnet restore
-        run: dotnet restore ZB.MOM.WW.OtOpcUa.slnx
+        run: dotnet build ZB.MOM.WW.OtOpcUa.slnx --no-restore --configuration Release -m:2
       # #606: the runner's size is the context every timing-sensitive failure needs and the log never
       # recorded it (load average included: the two Gitea runners may be running jobs side by side).
       - name: runner capacity
@@ -69,14 +63,15 @@ jobs:
       # are unreachable, so they run harmlessly here (and are counted by the skip-gate below).
       - name: dotnet test (whole solution, minus E2E + LiveIntegration)
         # #606: Akka TestKit time dilation for the Runtime + ControlPlane actor suites (read by their
-        # harnesses, tests/Server/*/Harness/TestTimeFactor.cs). This leg runs every test assembly at once
-        # on the runner, and their 2–8 s presence budgets — sized on an idle dev box — failed in a long
+        # harnesses, tests/Server/*/Harness/TestTimeFactor.cs). Their 2–8 s presence budgets
+        # — sized on an idle dev box — failed in a long
         # tail, a different test per run. Dilation only stretches waits: a presence wait still fails if
         # the message never comes, and absence windows get longer (stricter). Local runs stay at 1.
         env:
           AKKA_TEST_TIMEFACTOR: "3"
         run: >
-          dotnet test ZB.MOM.WW.OtOpcUa.slnx --configuration Release --no-restore
+          dotnet test ZB.MOM.WW.OtOpcUa.slnx --configuration Release --no-build
+          -m:1 -p:TestTfmsInParallel=false --settings scripts/ci/ci.runsettings
           --filter "Category!=E2E&Category!=LiveIntegration"
           --logger "trx" --results-directory artifacts/trx
       # 07/S-2 fail-on-skip: a whole-solution run that executed ZERO tests is a masked outage

scripts/ci/README.md

@@ -0,0 +1,30 @@
+# Whole-solution CI
+
+The `v2-ci` workflow restores, builds and tests in one job so the test step uses
+that job's Release binaries. Restore disables parallel package work; restore and
+build use at most two MSBuild workers. Testing uses one MSBuild worker, disables
+parallel target-framework runs and loads `ci.runsettings`: one VSTest process and
+two xUnit collection workers with conservative scheduling. Assemblies that disable
+parallelization keep that setting.
+
+The workflow retains the E2E/LiveIntegration exclusions, includes SlowUnit, keeps
+Akka's test time factor at three, and requires at least 12,000 executed tests.
+Runner capacity and TRX files remain available for diagnosing failures. These
+limits reduce contention; they do not prove every timing failure has one cause.
+There are no automatic test retries or changed assertion deadlines.
+
+Gitea 1.26 supports the repository-wide `lmxopcua-v2-ci` concurrency group. Only
+one run is active; an active run is not cancelled, but a newer pending run may
+supersede an older pending run. The group does not serialize other repositories
+using the same host.
+
+To reproduce the bounded test leg after restore and Release build:
+
+```bash
+AKKA_TEST_TIMEFACTOR=3 dotnet test ZB.MOM.WW.OtOpcUa.slnx \
+  --configuration Release --no-build -m:1 -p:TestTfmsInParallel=false \
+  --settings scripts/ci/ci.runsettings \
+  --filter "Category!=E2E&Category!=LiveIntegration" \
+  --logger trx --results-directory artifacts/trx
+MIN_EXECUTED=12000 bash scripts/ci/assert-not-all-skipped.sh artifacts/trx/*.trx
+```

scripts/ci/ci.runsettings

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RunSettings>
+  <!-- #707: project scheduling is also bounded by dotnet test -m:1. -->
+  <RunConfiguration>
+    <MaxCpuCount>1</MaxCpuCount>
+  </RunConfiguration>
+  <xUnit>
+    <!-- Preserve each assembly's parallelization opt-out; bound enabled collections. -->
+    <MaxParallelThreads>2</MaxParallelThreads>
+    <ParallelAlgorithm>conservative</ParallelAlgorithm>
+  </xUnit>
+</RunSettings>