Hi all, I have a problem with prefect-snowflake an...
# ask-communitym
Marcin Grzybowski
08/16/2022, 11:26 AMHi all, I have a problem with prefect-snowflake and/or concurrentTaskRunner and/or asyncio:
I'm trying to run ~10 snowflake queries simultaneously (example code in thread)
And only 4 or 5 or 6 are picked, the rest queries run when some previous query finishes.
It looks that the threads do not "go to sleep" as intended when they wait for snowflake results and because of that other tasks are not picked.
Marcin Grzybowski
08/16/2022, 11:27 AMthis is simple reproduction
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for x in range(10):
snowflake_multiquery.submit(["select count(*) from (select seq4() from TABLE(GENERATOR(ROWCOUNT => 1000000000000)) )"], snowflake_credentials, as_transaction=transaction)Marcin Grzybowski
08/16/2022, 11:30 AMthis is the code from prefect_snowflake/database.py that causes the problem
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with connection.cursor(cursor_type) as cursor:
results = []
for query in queries:
response = cursor.execute_async(query, params=params)
query_id = response["queryId"]
while connection.is_still_running(
connection.get_query_status_throw_if_error(query_id)
):
await asyncio.sleep(0.05)
cursor.get_results_from_sfqid(query_id)
result = cursor.fetchall()
results.append(result) Copy code
`asyncio.sleep(0.05)`Marcin Grzybowski
08/16/2022, 11:31 AMI don't know if it's issue with snowflake connector or with asyncio or with concurrent task runner...
And that 1s workaround probably isn't perfect.
Maybe someone will have some ideas...
Marcin Grzybowski
08/16/2022, 11:33 AMI can use daskTaskRunner but am curious how to run that code with ConcurrentTaskRunner as well
Marcin Grzybowski
08/16/2022, 11:37 AMit's prefect 2.0.2
b
Bianca Hoch
08/16/2022, 8:58 PMHi Marcin!
And only 4 or 5 or 6 are picked, the rest queries run when some previous query finishes.At first glance, this sounds like maybe a concurrency limit issue. Have you set a limit for the flows/tasks? https://docs-v1.prefect.io/orchestration/flow-runs/concurrency-limits.html#flow-run-limits
m
Marcin Grzybowski
08/17/2022, 7:14 AMHi, I haven't set it. I will try this, but as I wrote above, I am able to run 10 tasks concurrently, when I change asyncio.sleep time in prefect_snowflake module...
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