Hi Everyone, Had one case where i need a flow level concurrency. like in the workqueues we can set the concurrency. is it possible to set the concurrency at flows level ?

Hi Nimesh! There is deployment-level concurrency available, which limits how many flow runs of a particular deployment can be active at a given time.

Hi Bianca, Thankyou for the response But, Let suppose i have 4 deployment and i put concurrency 1 to each deployment. So then at one point of time 4 flows can be in the running state But i want only 2 flows in the running state at a given point of time

Hmm.. if that's the case then I'd say work queue and workpool concurrency would probably be your best bet. Is there a reason you're looking for an alternative?

We have 4 ai algorithms which correspond to 4 different deployment with diff queues attached to it And each of the 4 algorithms has 4 dockers which requires high compute and since and this is On Premise client so resource is a issue here thats why we want to run only 2 algo at a time

I see. So maybe you could try this? 1. Create a single work pool for all 4 of your deployments. 2. Set a concurrency limit of 2 on this work pool. 3. Assign all 4 deployments to this work pool, each with its own work queue. That way regardless of which deployment or work queue a flow run comes from, only 2 will be running concurrently across all deployments. You could even designate the priority of the work queues if there is an algorithm that takes precedence over the others.

Ahh i see this might get the job done, just to confirm This is possible in prefect 2.7.7 ?

for sure!

Thanks bianca 🫡

Hi Nimesh, thanks for sharing. What command did you use to start your agent?

when i have used this

prefect agent start -q my-queue -p default-agent-pool

then my flows were stuck into Late state and when i ran

prefect agent start -q my-queue

then queue were assinged into default-agent-pool (which i was expecting) but when i put concurrency in the default-agent-pool for example 2 then it did not restrict the flow to 2 reather it gets restricted to 5 which was a concurrency limit of my work queue

> when i have used this

prefect agent start -q my-queue -p default-agent-pool

then my flows were stuck into Late state I think adding the

-p

argument is needed for the pool-level concurrency to be respected, then. 🤔 As for the pool accumulating late runs, are there any flow runs stuck in a

PENDING

or

CANCELLING

state? Any runs in those states will also count against the concurrency work pool's limit.

not there is aren't any flow runs that are stuck into PENDING or CANCELLING. also do i need to change anything in this

prefect agent start -q my-queue -p default-agent-pool

or

prefect agent start -q my-queue

command becasue in the first command -p is there. ?

The only thing you need to change about this command would be the queue name and pool name (so that it matches your own):

prefect agent start -q my-queue -p default-agent-pool