Back again with DB QueuePool errors. But this time...
# prefect-community
t
Back again with DB QueuePool errors. But this time I have the whole stack trace! Anybody know how to solve this? Stack Trace in thread. I am running Postgres backend on Prefect 2.0
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Traceback (most recent call last):
  File "/home/tenders/Documents/code/prefect-orion/prefect_orion/accounts/accounts_subscriptions.py", line 339, in <module>
    flow_result = main()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/flows.py", line 384, in __call__
    return enter_flow_run_engine_from_flow_call(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 152, in enter_flow_run_engine_from_flow_call
    return anyio.run(begin_run)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_core/_eventloop.py", line 70, in run
    return asynclib.run(func, *args, **backend_options)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 292, in run
    return native_run(wrapper(), debug=debug)
  File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.10/asyncio/base_events.py", line 646, in run_until_complete
    return future.result()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 287, in wrapper
    return await func(*args)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/client.py", line 105, in with_injected_client
    return await fn(*args, **kwargs)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 228, in create_then_begin_flow_run
    return state.result()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/orion/schemas/states.py", line 145, in result
    raise data
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 566, in orchestrate_flow_run
    result = await run_sync(flow_call)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 56, in run_sync_in_worker_thread
    return await anyio.to_thread.run_sync(call, cancellable=True)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/to_thread.py", line 31, in run_sync
    return await get_asynclib().run_sync_in_worker_thread(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 937, in run_sync_in_worker_thread
    return await future
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 867, in run
    result = context.run(func, *args)
  File "/home/tenders/Documents/code/prefect-orion/prefect_orion/accounts/accounts_subscriptions.py", line 316, in main
    items = get_items_list.map(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/tasks.py", line 627, in map
    return enter_task_run_engine(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 705, in enter_task_run_engine
    return run_async_from_worker_thread(begin_run)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 136, in run_async_from_worker_thread
    return anyio.from_thread.run(call)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/from_thread.py", line 49, in run
    return asynclib.run_async_from_thread(func, *args)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 970, in run_async_from_thread
    return f.result()
  File "/usr/lib/python3.10/concurrent/futures/_base.py", line 446, in result
    return self.__get_result()
  File "/usr/lib/python3.10/concurrent/futures/_base.py", line 391, in __get_result
    raise self._exception
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 756, in begin_task_map
    return await gather(*task_runs)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 339, in gather
    async with create_gather_task_group() as tg:
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 317, in __aexit__
    retval = await self._task_group.__aexit__(*tb)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/anyio/_backends/_asyncio.py", line 662, in __aexit__
    raise exceptions[0]
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/utilities/asyncutils.py", line 286, in _run_and_store
    self._results[key] = await fn(*args)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 800, in create_task_run_then_submit
    task_run = await create_task_run(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/engine.py", line 840, in create_task_run
    task_run = await flow_run_context.client.create_task_run(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/client.py", line 1686, in create_task_run
    response = await <http://self._client.post|self._client.post>(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1842, in post
    return await self.request(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1527, in request
    return await self.send(request, auth=auth, follow_redirects=follow_redirects)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/client.py", line 259, in send
    await super().send(*args, **kwargs)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1614, in send
    response = await self._send_handling_auth(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1642, in _send_handling_auth
    response = await self._send_handling_redirects(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1679, in _send_handling_redirects
    response = await self._send_single_request(request)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_client.py", line 1716, in _send_single_request
    response = await transport.handle_async_request(request)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/httpx/_transports/asgi.py", line 152, in handle_async_request
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/applications.py", line 269, in __call__
    await super().__call__(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/applications.py", line 124, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await <http://self.app|self.app>(scope, receive, _send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/middleware/cors.py", line 84, in __call__
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/exceptions.py", line 93, in __call__
    raise exc
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/exceptions.py", line 82, in __call__
    await <http://self.app|self.app>(scope, receive, sender)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/routing.py", line 670, in __call__
    await route.handle(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/routing.py", line 418, in handle
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/applications.py", line 269, in __call__
    await super().__call__(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/applications.py", line 124, in __call__
    await self.middleware_stack(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/middleware/errors.py", line 184, in __call__
    raise exc
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/middleware/errors.py", line 162, in __call__
    await <http://self.app|self.app>(scope, receive, _send)
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File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/exceptions.py", line 93, in __call__
    raise exc
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/exceptions.py", line 82, in __call__
    await <http://self.app|self.app>(scope, receive, sender)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 21, in __call__
    raise e
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/middleware/asyncexitstack.py", line 18, in __call__
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/routing.py", line 670, in __call__
    await route.handle(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/routing.py", line 266, in handle
    await <http://self.app|self.app>(scope, receive, send)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/starlette/routing.py", line 65, in app
    response = await func(request)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/orion/utilities/server.py", line 101, in handle_response_scoped_depends
    response = await default_handler(request)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/routing.py", line 227, in app
    raw_response = await run_endpoint_function(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/fastapi/routing.py", line 160, in run_endpoint_function
    return await dependant.call(**values)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/orion/api/task_runs.py", line 46, in create_task_run
    model = await models.task_runs.create_task_run(session=session, task_run=task_run)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/orion/database/dependencies.py", line 112, in async_wrapper
    return await fn(*args, **kwargs)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/prefect/orion/models/task_runs.py", line 61, in create_task_run
    await session.execute(insert_stmt)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/ext/asyncio/session.py", line 215, in execute
    result = await greenlet_spawn(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/util/_concurrency_py3k.py", line 126, in greenlet_spawn
    result = context.throw(*sys.exc_info())
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 1711, in execute
    conn = self._connection_for_bind(bind)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 1552, in _connection_for_bind
    return self._transaction._connection_for_bind(
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/orm/session.py", line 747, in _connection_for_bind
    conn = bind.connect()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/future/engine.py", line 406, in connect
    return super(Engine, self).connect()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3315, in connect
    return self._connection_cls(self, close_with_result=close_with_result)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 96, in __init__
    else engine.raw_connection()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3394, in raw_connection
    return self._wrap_pool_connect(self.pool.connect, _connection)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 3361, in _wrap_pool_connect
    return fn()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 310, in connect
    return _ConnectionFairy._checkout(self)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 868, in _checkout
    fairy = _ConnectionRecord.checkout(pool)
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 476, in checkout
    rec = pool._do_get()
  File "/home/tenders/.cache/pypoetry/virtualenvs/prefect-orion-HonJDUqB-py3.10/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 134, in _do_get
    raise exc.TimeoutError(
sqlalchemy.exc.TimeoutError: QueuePool limit of size 5 overflow 10 reached, connection timed out, timeout 30.00 (Background on this error at: <https://sqlalche.me/e/14/3o7r>)
Other helpful data, I am using the default ConcurrentTaskRunner, and I can successfully process 1500 mapped tasks, but not the full 3000 on this Flow. I have some flows that map more than 3000 tasks, so I need to solve this problem. Thank you!
z
Hey Tim, this one will be best reported as an issue on GitHub as it’s pretty low level.
t
No worries, I will head over there!
z
Thanks for opening that issue! I believe we’ve got a simple suggestion for you.
t
Tried your suggestion this morning and came back with a different error. Info in the issue, if that is an OK way to handle it. Track the journey of the problem in one place.
Would you consider this high volume? would there be some DB setup/settings that are recommended for a situation like this?