AuditLog.Tests flaked under parallel full-solution runs. Three distinct mechanisms, all load-sensitive and all green in isolation. 1. MsSqlMigrationFixture create+migrate saturation (the register's headline). Database NAMING was already isolated (a guid per fixture), but nothing bounded how many fixtures ran CREATE DATABASE + the ~100-migration chain at once. xunit parallelises processor-count collections PER PROCESS, and a solution-level `dotnet test` starts several MSSQL-backed processes together, so the dev container saw dozens of simultaneous fresh-database migrations. That is resource saturation, not object-level locking, and it pushed individual DDL statements past EF's default 30s command timeout — every failure had the identical fingerprint the register recorded: MsSqlMigrationFixture..ctor -> Migrator.MigrateAsync -> SqlException "Execution Timeout Expired" (error 258), which xunit surfaces as "Class fixture type ... threw in its constructor" against every test in the class. Fix: a machine-wide counting semaphore over the create+migrate window, built from sp_getapplock on master (ScadaBridgeTestMigrate/0..N-1, default 4 slots, SCADABRIDGE_MSSQL_TEST_MIGRATE_SLOTS to override). An xunit collection cannot do this — the contention is cross-PROCESS, so the arbiter has to live on the shared server. The gate connection is unpooled (a pooled connection defers the implicit release of a session-scoped app lock until reuse) and releases explicitly; a crashed process drops its connection and SQL releases the lock, so the gate cannot wedge the suite, and a deadline miss proceeds ungated rather than failing. Migration commands also get a 300s timeout and CREATE/DROP DATABASE 120s: under a bounded queue the server is busy but progressing, so waiting is the correct response. Plus a once-per-process best-effort sweep of ScadaBridgeAuditMigTest_* databases older than 2h so a killed run does not leave strays, and the connectivity probe now retries (3 attempts) — a busy server misread as an absent one would silently turn every MSSQL test into a Skip, which reads green and is worse than a red. 2. PartitionPurgeTests leaked AuditLogPurgeActors. Each ticks every 100ms and switches out the Jan-2026 partition; they were only stopped implicitly by TestKit Dispose -> Shutdown, which is timeout-bounded and does not fail when it expires. Under load a previous test's actor was still ticking against the shared per-class fixture DB, so PerChannelOverride_... found its seeded Jan-15-2026 row already gone (Expected: 1, Actual: 0). 3. NotifyDispatcherAuditTrailTests leaked NotificationOutboxActors, same shape. The dispatcher claims EVERY due row, not just the test's siteId, so a leaked actor delivered the next test's notification through its own exhausted QueuedOutcomeAdapter — a transient outcome, leaving the row in Retrying (Expected: Delivered, Actual: Retrying) and audit counts short. Both fixed by stopping the actor inside the test that created it (Watch/Stop/ExpectTerminated), removing the dependency on shutdown timing. Evidence. Reproducer: 10 concurrent ConfigurationDatabase.Tests processes against the one dev SQL Server — before, 10/10 processes failed (17-77 failures each, 100% the ctor->MigrateAsync timeout); after, 3 consecutive runs 10/10 green, 395/395 each. Realistic shape (3x AuditLog.Tests + 1x ConfigurationDatabase.Tests concurrent): first post-fix run still showed the NotifyDispatcher leak, then 3 consecutive clean runs. Standalone: AuditLog.Tests 383/383, ConfigurationDatabase.Tests 395/395 (12s, unchanged from baseline), SiteCallAudit.Tests 66/66. No orphan databases or stuck app locks left behind. docs/test_infra/test_infra_db.md documents the ephemeral per-test-class databases, the throttle and its env override, the timeouts, and the stray sweep.
8.4 KiB
Test Infrastructure: MS SQL 2022 Database
Overview
The test database uses Microsoft SQL Server 2022 Developer Edition running in Docker. It provides two empty databases for ScadaBridge — schema creation is handled by EF Core migrations at application startup (dev mode).
Image & Ports
- Image:
mcr.microsoft.com/mssql/server:2022-latest - Port: 1433
- Edition: Developer (free, full-featured)
Credentials
| Account | Username | Password | Purpose |
|---|---|---|---|
| SA | sa |
ScadaBridge_Dev1# |
Server admin (setup only) |
| App | scadabridge_app |
ScadaBridge_Dev1# |
Application login (db_owner on both databases) |
Databases
| Database | Purpose |
|---|---|
ScadaBridgeConfig |
Configuration Database component — templates, deployments, users, audit log |
ScadaBridgeMachineData |
Machine/operational data storage |
Both databases are created by infra/mssql/setup.sql. EF Core migrations populate the ScadaBridgeConfig schema. The ScadaBridgeMachineData database is seeded with sample tables and stored procedures by infra/mssql/machinedata_seed.sql.
Ephemeral per-test-class databases
MsSqlMigrationFixture (tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/Migrations/) creates a
throwaway ScadaBridgeAuditMigTest_<guid> database per test class, applies the full EF migration chain
to it, and drops it on teardown. Both ConfigurationDatabase.Tests and AuditLog.Tests use it — the
latter by project reference, so there is one fixture implementation, not a copy. Seeing a handful of
these databases come and go while tests run is normal; seeing them survive a run is not (see below).
Three behaviours are worth knowing when you look at this server during a test run:
- Concurrent create+migrate is throttled machine-wide. Fixtures take a slot from a counting
semaphore built on
sp_getapplockinmaster(resourcesScadaBridgeTestMigrate/0..N-1) and hold it acrossCREATE DATABASE+ the migration chain. The default is 4 slots; override withSCADABRIDGE_MSSQL_TEST_MIGRATE_SLOTS. An xunit collection attribute cannot do this job — a solution-leveldotnet testruns several MSSQL-backed test processes at once, so the throttle has to live on the shared server. Without it, dozens of simultaneous fresh-database migrations saturated the container and individual DDL statements blew past EF's default 30-second command timeout, failing whole test classes at fixture construction (deferred-work register row 82). - Migration commands use a 300s timeout, and CREATE/DROP DATABASE use 120s. Under a bounded queue the server is busy but progressing, so the correct response to a slow statement is to wait.
- Strays are swept. Each test process drops, once at start and best-effort, any
ScadaBridgeAuditMigTest_*database older than 2 hours, so a run killed before teardown does not leave databases accumulating. To clear them by hand:
docker exec -i scadabridge-mssql /opt/mssql-tools18/bin/sqlcmd \
-S localhost -U sa -P 'ScadaBridge_Dev1#' -C \
-Q "SELECT name, create_date FROM sys.databases WHERE name LIKE 'ScadaBridgeAuditMigTest_%'"
Overriding the server the fixture targets (CI, a non-default port) is done with
SCADABRIDGE_MSSQL_TEST_CONN. When no server answers, the fixture reports Available = false and the
tests report as Skipped, not passed.
Data Persistence
SQL data is stored in the named Docker volume scadabridge-mssql-data. Data survives container restarts and docker compose down. To reset the database completely:
docker compose down -v
docker compose up -d
# Re-run setup.sql after the container starts
First-Time Setup
After the first docker compose up -d, run the setup script:
docker exec -i scadabridge-mssql /opt/mssql-tools18/bin/sqlcmd \
-S localhost -U sa -P 'ScadaBridge_Dev1#' -C \
-i /docker-entrypoint-initdb.d/setup.sql
This creates the databases and the scadabridge_app login. Then seed the Machine Data database with sample tables, stored procedures, and data:
docker exec -i scadabridge-mssql /opt/mssql-tools18/bin/sqlcmd \
-S localhost -U sa -P 'ScadaBridge_Dev1#' -C \
-i /docker-entrypoint-initdb.d/machinedata_seed.sql
You only need to run these once (or again after deleting the volume).
Connection Strings
For appsettings.Development.json:
Server=localhost,1433;Database=ScadaBridgeConfig;User Id=scadabridge_app;Password=ScadaBridge_Dev1#;TrustServerCertificate=true
Server=localhost,1433;Database=ScadaBridgeMachineData;User Id=scadabridge_app;Password=ScadaBridge_Dev1#;TrustServerCertificate=true
Verification
- Check the container is running:
docker ps --filter name=scadabridge-mssql
- Query using
sqlcmdinside the container:
docker exec -it scadabridge-mssql /opt/mssql-tools18/bin/sqlcmd \
-S localhost -U sa -P 'ScadaBridge_Dev1#' -C \
-Q "SELECT name FROM sys.databases"
- Verify the app login:
docker exec -it scadabridge-mssql /opt/mssql-tools18/bin/sqlcmd \
-S localhost -U scadabridge_app -P 'ScadaBridge_Dev1#' -C \
-d ScadaBridgeConfig \
-Q "SELECT DB_NAME()"
CLI Tool
The infra/tools/mssql_tool.py script provides a convenient CLI for interacting with the SQL Server.
Install dependencies (one-time):
pip install -r infra/tools/requirements.txt
Commands:
# Check connectivity and verify expected databases exist
python infra/tools/mssql_tool.py check
# Run the first-time setup script (uses autocommit mode for CREATE DATABASE)
python infra/tools/mssql_tool.py setup --script infra/mssql/setup.sql
# List tables in a database
python infra/tools/mssql_tool.py tables --database ScadaBridgeConfig
# Run an ad-hoc query
python infra/tools/mssql_tool.py query --database ScadaBridgeConfig --sql "SELECT name FROM sys.tables"
Use --host, --port, --user, --password to override defaults (localhost:1433, sa, ScadaBridge_Dev1#). Run with --help for full usage.
Machine Data Tables & Stored Procedures
The machinedata_seed.sql script creates the following in ScadaBridgeMachineData:
Tables:
| Table | Description | Sample Data |
|---|---|---|
TagHistory |
Time-series tag values from OPC UA / custom protocols | Pressure, flow, level, temperature, speed readings for SiteA/SiteB |
ProductionCounts |
Shift/line production totals (good, reject, efficiency) | 3 days of 2-shift data across 2 sites |
EquipmentEvents |
State changes, faults, maintenance, alarm events | Pump faults, belt inspections, batch starts |
BatchRecords |
Production batch tracking (start, complete, abort) | 5 batches including one in-progress |
AlarmHistory |
Historical alarm activations, acks, and clears | Active, acknowledged, and cleared alarms |
Stored Procedures:
| Procedure | Description |
|---|---|
usp_GetTagHistory |
Get tag values for a tag path within a date range |
usp_GetProductionSummary |
Aggregate production by line over a date range |
usp_InsertBatchRecord |
Insert a new batch (for CachedWrite testing) |
usp_CompleteBatch |
Complete or abort a batch |
usp_GetEquipmentEvents |
Get recent equipment events with optional filters |
usp_GetActiveAlarms |
Get active/acknowledged alarms by severity |
Relevance to ScadaBridge Components
- Configuration Database — primary consumer; EF Core context targets
ScadaBridgeConfig. - Deployment Manager — reads/writes deployment records in
ScadaBridgeConfig. - Template Engine — reads/writes template definitions in
ScadaBridgeConfig. - Security & Auth — user/role data stored in
ScadaBridgeConfig. - External System Gateway — scripts use
Database.Connection("machineDataConnection")to queryScadaBridgeMachineDatatables and stored procedures. - Site Runtime — scripts call stored procedures via
Database.Connection()andDatabase.CachedWrite()for batch recording and data queries. - Inbound API — methods can query machine data via named database connections.
Notes
- The
sapassword must meet SQL Server complexity requirements (uppercase, lowercase, digit, special character, 8+ characters). - If the container fails to start, check Docker has at least 2GB RAM allocated (SQL Server minimum requirement).
- The setup script is idempotent — safe to run multiple times.