Message queue vs database for delayed tasks

Question

I need to build a system that can handle a fairly high amount of delayed tasks (e.g. scheduled emails). For non-delayed tasks I would go for something like RabbitMQ.

But, is it ok to let tasks lingering in the queue for extended amounts of time, like days?

Would it make more sense to store the tasks in a database and then periodically check whether there are tasks which need to be processed?

Answer 1

Systems such as RabbitMQ (or in your case maybe look into Kafka) can offer persistence, or guaranteed delivery, as well as configurable TTL on messages. However, they are not designed as a long-term persistent storage solution, and if we're talking about days, I would actually store the job in a DB as you suggest.