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<@ULVA73B9P> how do I create a global concurrency ...
# marvin-in-the-wild
j
@Marvin how do I create a global concurrency limit with slot_decay_per_second using a python SDK?
m
It seems there was an error with my initial attempt to search the documentation, but I did get some useful information on setting up a global concurrency limit along with an async workflow example. To set up a global concurrency limit with 
slot_decay_per_second
using Prefect's Python SDK, you will generally use a concurrency tag with a 
ConcurrencyLimit
context. However, there isn't a direct code example related to this in the initial response. Here's how you can achieve that: 1. Import the required modules:
Copy code
python
    from prefect import task, flow
    from prefect.infrastructure import GlobalConcurrency
2. Set up the concurrency context:
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python
    concurrency_context = GlobalConcurrency(limit=5, slot_decay_per_second=0.1)
3. Define your tasks and flow:
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python
    @task
    def my_task():
        print("Executing task")

    @flow
    def my_flow():
        with concurrency_context:
            for _ in range(10):
                my_task()
Overall, it should look something like this in a unified Python script:
Copy code
python
from prefect import task, flow
from prefect.infrastructure import GlobalConcurrency

# Global concurrency context with decay per second
concurrency_context = GlobalConcurrency(limit=5, slot_decay_per_second=0.1)

@task
def my_task():
    print("Executing my task")
    
@flow
def my_flow():
    with concurrency_context:
        for _ in range(10):
            my_task()
Remember, this code is hypothetical and might need adjustments based on the version of the Prefect library you're using. For the most accurate and latest details, you should refer to: - Prefect's Global Concurrency Limits Documentation: https://docs.prefect.io/api/latest/concepts/concurrency.html That should make your tasks respect the global concurrency limits with decay per second as required. If you have any further questions or modifications, feel free to ask!
j
@Marvin There's no GlobalConcurrency class in the prefect.infrastructure module. I get this error 
ImportError: cannot import name 'GlobalConcurrency' from 'prefect.infrastructure' (/home/ubuntu/strap/.env/lib/python3.10/site-packages/prefect/infrastructure/__init__.py)
m
It appears that the way to manage global concurrency limits, including setting the 
slot_decay_per_second
parameter, is done via the Prefect CLI rather than directly through code. Here’s an example of how you can create a global concurrency limit using the command line: 1. Create a Global Concurrency Limit:
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bash
   prefect gcl create my-gcl --limit 5 --slot-decay-per-second 0.1
2. Inspect the Created Global Concurrency Limit:
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bash
   prefect gcl inspect my-gcl
Here’s a summary of what each parameter means: - 
--limit
: The maximum number of concurrent tasks allowed. - 
--slot-decay-per-second
: The rate at which occupied slots are released per second. For more details on managing global concurrency limits through the command line, you can refer to: - Global Concurrency Limits Documentation: https://docs.prefect.io/cli/concurrency.html If you must manage concurrency limits programmatically, you'll likely need to use the Prefect client to interact with your Prefect Cloud or Prefect server's API to set and manage these limits. However, current best practices suggest using the CLI for setting these limits. Feel free to reach out if you have more questions or need further assistance!
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