Scheduled tasks missing from GatedTaskKeys run on every replica #14

New Issue

2026-09-13T13:33:15+10:00

unkin-agent commented

2026-09-13 13:33:15 +10:00

Context: multi-replica stateless deployment (two 2-replica apps, cheeztv and fafflix, each one PostgreSQL plus valkey, no sticky sessions). Not a 12.0 regression — live in the deployed build. Tracking: #12.

Problem

MediaBrowser.Controller/ScheduledTasks/ScanLeaderOptions.cs:26-36 gates only some timer-driven tasks on the scan leader. Ungated, and therefore running on every replica:

DownloadLyrics
DownloadSubtitles
TmdbRefreshUpcomingEpisodes
RefreshTrickplayImages
MoveTrickplayImages
RefreshInternetChannels
RefreshGuide
PluginUpdateTask

Consequences: N× duplicate ffmpeg and network work, third-party API quota burned N× over, racing writes to the same rows, and concurrent plugin-assembly writes into the shared /config/plugins.

Scope: this issue is only about the key list. The separate Jellyfin:ScanLeader:Enabled default is handled in PR #11.

Proposal

Add the keys above to GatedTaskKeys.

Add a test pinning every entry of GatedTaskKeys to a task key that actually exists — a key matching nothing silently un-gates its task, so a typo or an upstream rename degrades to the current behaviour with no signal. There is already precedent for this test in the repo.

Acceptance

All eight keys present in GatedTaskKeys.
A test asserts every entry of GatedTaskKeys resolves to a registered IScheduledTask key, failing on a typo or an upstream rename.
A test asserts a non-leader instance does not execute a gated task on its timer trigger.

Context: multi-replica stateless deployment (two 2-replica apps, `cheeztv` and `fafflix`, each one PostgreSQL plus valkey, no sticky sessions). Not a 12.0 regression — live in the deployed build. Tracking: #12. ## Problem `MediaBrowser.Controller/ScheduledTasks/ScanLeaderOptions.cs:26-36` gates only some timer-driven tasks on the scan leader. Ungated, and therefore running on every replica: - `DownloadLyrics` - `DownloadSubtitles` - `TmdbRefreshUpcomingEpisodes` - `RefreshTrickplayImages` - `MoveTrickplayImages` - `RefreshInternetChannels` - `RefreshGuide` - `PluginUpdateTask` Consequences: N× duplicate ffmpeg and network work, third-party API quota burned N× over, racing writes to the same rows, and concurrent plugin-assembly writes into the shared `/config/plugins`. Scope: this issue is only about the key list. The separate `Jellyfin:ScanLeader:Enabled` default is handled in PR #11. ## Proposal Add the keys above to `GatedTaskKeys`. Add a test pinning every entry of `GatedTaskKeys` to a task key that actually exists — a key matching nothing silently un-gates its task, so a typo or an upstream rename degrades to the current behaviour with no signal. There is already precedent for this test in the repo. ## Acceptance - All eight keys present in `GatedTaskKeys`. - A test asserts every entry of `GatedTaskKeys` resolves to a registered `IScheduledTask` key, failing on a typo or an upstream rename. - A test asserts a non-leader instance does not execute a gated task on its timer trigger.

unkin-agent referenced this issue

2026-09-13 13:33:42 +10:00

HA: in-process single-instance assumptions under multi-replica deployment (tracking) #12

unkin-agent referenced a pull request that will close this issue

2026-09-20 23:36:42 +10:00

fix(ha): gate the remaining timer-driven scheduled tasks #28

benvin closed this issue

2026-09-21 07:40:33 +10:00

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