Stratara.Sessions 4.4.2

• net10.0

  • Microsoft.AspNetCore.Http.Abstractions (>= 2.3.12)
  • Microsoft.Extensions.DependencyInjection.Abstractions (>= 10.0.11)
  • Microsoft.Extensions.Options (>= 10.0.11)
  • Microsoft.Extensions.Options.ConfigurationExtensions (>= 10.0.11)
  • OpenTelemetry.Api (>= 1.18.0)
  • Stratara.Abstractions (>= 4.4.2)
  • Stratara.Contracts (>= 4.4.2)
  • Stratara.Diagnostics (>= 4.4.2)

A release about a flag that cost too much. Every host sharing the replay coordination state over Redis
asked Redis, with a blocking round trip on the calling thread, whether a replay was active — and the
Orleans execution model asked on every hot path, eight to ten times per command on a host with three
projections, inside grain turns. On a two-core host that was enough to starve the thread pool and time
the Redis connection out, surfacing as failed catch-ups, lagging read models and failed grain
registrations although no replay ever ran. The answer now comes from memory. No migration is needed;
one optional setting is new.

### Fixed

- **No path waits on Redis to learn whether a replay is active.** The Redis-backed replay state answers
 `IsReplayActive` from a field. A change made in the host itself is seen there at once; a change made
 elsewhere — a replay that began or ended in another host, or a marking that lapsed — is announced over
 a channel beside the replay-request channel and seen within its latency, and every host re-reads the
 marking every `ProjectionReplay:RefreshSeconds` regardless, as the safety net for a lost announcement.
 The Orleans execution model's command dispatcher, bundle dispatcher, store readers and drain, and the
 bus dispatchers, make no Redis call for it any more. Nothing changes for a host without Redis, whose
 state was in process already, nor for a host that registers its own `IProjectionReplayState`.

### Added

- **`ProjectionReplayOptions.RefreshSeconds`** (default 5), read from the `ProjectionReplay` section
 like the lease. It bounds how long a host answers from a replay marking that changed elsewhere where the
 announcement was lost. Refused when the host starts at zero or below, and at or above
 `LeaseSeconds`, with an `OptionsValidationException` naming `ProjectionReplay:RefreshSeconds`.
- **Log events `104_015` to `104_018`.** A host that cannot refresh the replay marking from Redis says
 so once at Warning (`104_015`) and keeps its last answer; `104_016` at Information says it reads the
 marking again. A host that cannot subscribe to the marking's announcements says so once at Warning
 (`104_017`), sees a change on the refresh period only, and `104_018` says it is subscribed again.

### Changed

- **A host that cannot reach Redis keeps its last answer about the replay.** Before, every dispatch and
 every catch-up on such a host failed with the connection's exception. Now they proceed on what the host
 last learned — initially that no replay is active — and the loss is logged once. The replay stays
 correct regardless: on the Orleans execution model the readers are paused by the rebuild and the
 replay themselves, and apply the store from the beginning once more when the replay ends.
- **Rolling upgrade.** A host on a release before this one announces nothing when it starts or ends a
 replay, so a host on this release sees that replay at the refresh period rather than at once. The
 marking, its key and its lease are unchanged, so the two releases share one replay state.