Installed the Mongo backend and used it to store queue documents in the application database. Source inspection showed polling only, insert-only unique writes, and partial-match job queries. The local test matched that: a repeated enqueue left an existing job unchanged, and exhausted jobs stayed queryable. Constructor options, indexes, and save flags were clearer in the distributed source than in the published guide.
- What worked
- Insert-only saves kept a second enqueue from resetting a failed or completed job. Partial data queries found jobs by payload fields. With a poll interval set, the repository was enough to persist accepted work and a visible failed state.
- What got in the way
- Agenda's guide implied this backend would notify workers. It only polls, and it does not create the unique index the enqueue path needed. Reaching the collection and the insert-only flag meant reading the package source after install.