queue.put() inside a transaction sets enqueued_at to the transaction start time, not the current time about pq HOT 4 OPEN

Thanks - ultimately I defer to you as to whether the behaviour should be changed or not by default, as it's fairly trivial to override with a bit of SQL.

My use case that motivated this report: I want to perpetually process some tasks, and then re-queue them to be processed again in the near future. I dequeue and enqueue within the same transaction to be sure that the task is always in my queue. I expect to have hundreds of tasks and a handful of workers, so tasks may sit in the queue for a few minutes or more.

I want to measure and report on the length of time that tasks spend sitting in the queue, so that I can do something about it if that becomes too long. But for that I need an accurate enqueue time, otherwise I am also measuring the length of time taken by my task.

The motivation statement in my view: the enqueued_at time should be the time a task was enqueued. The start of a transaction is an implementation detail that has little relevance to that concept, rendering the timestamp somewhat arbitrary in this case.

from pq.

Oh, yup it does, even though it sounds quite specific.

Generally I don't think this should affect end-users too much, otherwise this issue would have been brought up already 😂
I'm totally ok with changing this!

from pq.

I can see why that might be more ideal, but to motivate this, do you have a specific situation where this is a problem? If we change the behavior, how would we motivate/document this change in the change log?

from pq.

@stas I think this makes sense.

from pq.