[bboreham]

If the requirement is for persistence, i.e. no data loss if the queue process dies, then Redis won't fit.

EDIT: TIL Redis has the option to turn on fsync-to-disk on every write. Probably not what people are thinking of when they suggest Redis as lightweight.

[mmjaa]

Redis has persistence if you need it. But only if.

[markbnj]

I would still call redis lightweight compared to mysql, but yes fsync always has a significant performance cost.