Jellyfin
Whether Jellyfin keeps its libraries current and its viewers served: scheduled tasks that failed on their last run (the library scan first), plugins that no longer load, a restart waiting, and what is playing right now, transcoded or not.
Network ports to open
Section titled “Network ports to open”From the DumbMonit server (or its relay agent) to the device:
| Port | Protocol | Purpose |
|---|---|---|
| 8096 | TCP | API (HTTP, default) |
| 8920 | TCP | Only with the https scheme on Jellyfin’s own HTTPS port |
DumbMonit reads Jellyfin’s API with an API key created in the dashboard. It never starts a task, never stops a playback and never changes a setting.
The failure worth watching: the library scan that fails every night. A network share unmounted, a disk full, and new films and episodes stop appearing; Jellyfin itself keeps playing what it already knows, and the only trace is a line in Scheduled Tasks.
What it watches
Section titled “What it watches”All metrics are prefixed dumbmonit_jellyfin_.
| Metric | What | Labels |
|---|---|---|
version_info | value 1 | version |
pending_restart | 1 when Jellyfin waits for a restart (after a plugin install or update) | |
shutting_down | 1 while Jellyfin shuts down | |
scheduled_tasks_failed, scheduled_tasks_running | tasks whose last run failed or was aborted; tasks running now | |
scheduled_task_failed | value 1 per failed task (at most 32) | task, error (first line of the message) |
library_scan_last_ok, library_scan_age_seconds | last run of “Scan Media Library”: succeeded or not, and how long ago it ended | |
plugins, plugins_broken | installed plugins; those that failed to load or do not support this version | |
plugin_broken | value 1 per broken plugin | plugin, status |
sessions, streams, streams_paused, transcodes | client sessions; those playing something, paused, and transcoding | |
scrape_errors | calls that failed on the last probe |
Jellyfin does not check for its own updates (the package or the image does), so there is no update metric.
The built-in rules that apply: Jellyfin scheduled task failed, Jellyfin plugin broken, Jellyfin restart pending, plus Monitor unreachable.
The monitor page
Section titled “The monitor page”The panel above the charts reads what the probe stored; opening the page never calls Jellyfin. It says what is wrong first (failed tasks, broken plugins, a restart waiting), then streams, transcodes, sessions and the age of the last library scan, then the failed tasks and broken plugins by name with Jellyfin’s own error.
Create an API key in Jellyfin
Section titled “Create an API key in Jellyfin”-
In Jellyfin, open Dashboard → Advanced → API Keys → + and name the key as follows, then copy it.
DumbMonit -
In DumbMonit, enter Jellyfin’s address and paste the key.
Vendor documentation: https://api.jellyfin.org/
Why a full-rights key
Section titled “Why a full-rights key”Jellyfin cannot limit what a key may do: every key has full rights on the server. It is still the only way to read scheduled tasks and everyone’s playback; an ordinary user sees neither.
DumbMonit only reads /System/Info, /ScheduledTasks, /Sessions and /Plugins. It never starts a task, never stops a playback and never changes a setting. Keep the key to a network you trust and put Jellyfin behind HTTPS across the internet.
Credentials
Section titled “Credentials”| Credential | Fields |
|---|---|
| API key | Sent in the Authorization: MediaBrowser … Token="…" header, the form Jellyfin 10.11 and later accept by default. |
Address: a host name (jellyfin.lan), host:port, or a full URL with a path
prefix (https://example.com/jellyfin); a trailing /web is accepted.
Options: protocol (HTTP by default), port (8096), certificate check and request
timeout (15 s).
Validated against Jellyfin 12.1.0 (official image).