Radarr & Sonarr Backlog
The Backlog pipeline searches for missing content — movies and episodes that are monitored in your library but have never been successfully grabbed.
What it does
Cutoff Unmet targets items you have but want better. Backlog targets items you do not have yet at all.
When Backlog is enabled for Radarr, Nudgarr tells each enabled Radarr instance to search for missing movies, filters the results, and nudges up to the configured maximum. The same applies independently for Sonarr.
Backlog and Cutoff Unmet are separate. They run within the same sweep but use different caps and record different history entries — Backlog vs Cutoff in the History tab.
Enabling Backlog
Backlog is off by default. To enable it:
- Open the Advanced tab
- Toggle Radarr Backlog and/or Sonarr Backlog to on
- Adjust Missing Max and other settings as needed
- Save
Settings
Missing Max
The maximum number of missing items to nudge per sweep, per instance. This is a separate cap from the Cutoff Unmet Max, which applies only to Cutoff Unmet searches.
Setting Missing Max to 0 means all eligible missing items are nudged each run. This is useful for smaller libraries but can generate a large number of searches quickly on libraries with many missing items — use with care.
Missing Added Days (Radarr only)
For Radarr, Nudgarr only considers missing movies that were added to your library at least this many days ago. This filter does not apply to Sonarr — all missing episodes are eligible regardless of when they were added. This filter exists to give your normal RSS grabber a reasonable window to find new releases before Nudgarr steps in.
Example: With the default of 14, a movie added to Radarr yesterday will not be included in backlog searches. A movie added 15 days ago will be eligible. Sonarr episodes have no equivalent filter.
Setting this to 0 disables the age filter — all missing items are eligible regardless of when they were added.
Backlog Sample Mode
Controls the order in which eligible missing items are picked for searching. Set independently for Radarr and Sonarr and independent of the Cutoff Unmet Sample Mode.
| Mode | Behaviour |
|---|---|
| Random | Picks items in a random order each run (default) |
| Alphabetical | Picks items sorted A to Z by title |
| Oldest Added | Prioritises items added to your library first |
| Newest Added | Prioritises items added most recently |
Grace Period (Radarr only)
Waits a configured number of hours after a missing movie's availability date before Nudgarr's first search. Useful when indexers need time to populate after a release. 0 disables the grace period — Nudgarr searches immediately once the item becomes available and passes the Missing Added Days filter.
How items are selected
After fetching missing items and applying the age filter, grace period, and exclusions list, Nudgarr applies the same cooldown check as Cutoff Unmet. Items already present in the download queue are silently skipped and do not consume a Backlog slot.
History labels
In the History tab, Backlog searches appear with the label Backlog. In the Imports tab they show an Acquired badge (green) — meaning the item was a first-time grab rather than a quality upgrade on something you already had.
Recommendations
- Start with
Missing Max: 1for both apps and see how your indexers respond before increasing the cap. - If you have a large backlog and want Nudgarr to work through it steadily, increasing Missing Max to 3-5 with Random sample mode spreads searches across different titles over time.
- The cooldown applies to backlog items the same as to Cutoff Unmet — if a missing movie was just searched, it will not be searched again until the cooldown window expires.
- Setting Missing Max to
0(all eligible) is powerful but can generate many search requests in a single sweep. Only use it if your library is small or your indexers handle volume well.