Source health: why a five seeder floor keeps a station on air
An index that only records where music lives is telling you half the story. The other half is whether the address still answers, and how quickly.
Seeders are a health signal, not a popularity contest
For a torrent, the seeder count is the number of peers holding a complete copy. It is the closest thing to a liveness check the network offers.
- Zero seeders. The address is dead. It may return, but you cannot broadcast on maybe.
- One or two. Technically alive, entirely dependent on somebody's home connection staying up.
- Five or more. Enough redundancy that one peer disappearing mid-track is survivable.
- Dozens. Fast to start, and reliable enough to schedule around.
A floor of five is not a magic number, it is a risk decision. Below it, a single disconnection becomes dead air. Above it, you are trading catalog breadth for reliability, since rare music tends to have fewer seeders precisely because it is rare.
Cold start is the other half
Seeder count tells you whether the music exists. It does not tell you how long it takes to arrive. Fetching a torrent involves finding peers before any audio moves, and that discovery can take the better part of a minute even when the swarm is healthy.
For on demand listening a wait is annoying. For a station it is fatal, because the next track has to start the instant the current one ends. The answer is to fetch ahead: pull the next track while the current one plays, so discovery finishes long before anyone needs the audio.
Caching what does not change
Most of that cold start is not the music at all, it is the torrent metadata: the file list and piece hashes. That metadata never changes, so fetching it more than once is wasted time. Cache it and the second play of anything from the same release is effectively instant.
The gain is larger than it first appears. A single album torrent typically holds fifteen to twenty tracks, so one cached metadata fetch covers an entire record.
Fall through, do not fail
Because a song usually exists in several releases, health should decide order rather than availability. Try the healthiest source, and if it stalls, move to the next before the listener hears anything. A track only fails when every source behind it fails, which for well seeded music is close to never.
Reliability in a pointer catalog is not about any single source being good. It is about always having another one ready.