The Pull*UseCase implementations issued one HTTP request at a time despite
Scraping:MaxConcurrentRequests=4. With 30–80 live events and ~1s per
fetch, a 5–10s live cadence target was unreachable; cycles overflowed
the configured interval.
* New Marathon.Application.Configuration.ScrapingThrottle bound from the
shared Scraping:* section. Exposes only MaxConcurrentRequests so the
Application layer doesn't pull in the Infrastructure-side ScrapingOptions.
* PullLiveOddsUseCase + PullUpcomingEventsUseCase split into two phases:
- Phase 1 — Parallel.ForEachAsync over the event list with
MaxDegreeOfParallelism = throttle.MaxConcurrentRequests. The scraper's
Polly rate limiter still throttles to RequestsPerSecond underneath
this fan-out, so spikes are smoothed before they hit the bookmaker.
- Phase 2 — sequential foreach over the (Event, Snapshot) tuples
captured in Phase 1, doing event upsert + snapshot insert. EF Core
DbContext is not thread-safe so all DB writes stay on a single thread.
* InfrastructureModule binds ScrapingThrottle alongside AnomalyOptions.
* Failed snapshot scrapes in Phase 1 mean the event row is also NOT
persisted in Phase 2 — previously we'd persist the row even when the
snapshot scrape failed, leaving an orphan event with no odds. Updated
the regression test accordingly.
* Test fixture exposes TestFixtures.Throttle(maxConcurrentRequests=1) for
deterministic sequential test runs.
* One existing NSubstitute setup that chained Arg.Is<>() across two
configurations was rewritten to use a single Arg.Any<>() with inline
branching — chained matchers were leaking and returning wrong results.
alexei.dolgolyov
286b55986b