Python 3.x asyncpg-无法执行操作：另一个操作正在进行

我正在尝试解决以下错误：

asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress

以下是完整的回溯：

Traceback (most recent call last):

  File "<string>", line 1, in <module>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/multiprocessing/spawn.py", line 116, in spawn_main
    exitcode = _main(fd, parent_sentinel)
               │     │   └ 4
               │     └ 7
               └ <function _main at 0x109c8aca0>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/multiprocessing/spawn.py", line 129, in _main
    return self._bootstrap(parent_sentinel)
           │    │          └ 4
           │    └ <function BaseProcess._bootstrap at 0x109b1f8b0>
           └ <SpawnProcess name='SpawnProcess-4' parent=36604 started>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/multiprocessing/process.py", line 315, in _bootstrap
    self.run()
    │    └ <function BaseProcess.run at 0x109b18ee0>
    └ <SpawnProcess name='SpawnProcess-4' parent=36604 started>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
    │    │        │    │        │    └ {'config': <uvicorn.config.Config object at 0x109cd55b0>, 'target': <bound method Server.run of <uvicorn.server.Server object...
    │    │        │    │        └ <SpawnProcess name='SpawnProcess-4' parent=36604 started>
    │    │        │    └ ()
    │    │        └ <SpawnProcess name='SpawnProcess-4' parent=36604 started>
    │    └ <function subprocess_started at 0x10a4aca60>
    └ <SpawnProcess name='SpawnProcess-4' parent=36604 started>
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/uvicorn/subprocess.py", line 61, in subprocess_started
    target(sockets=sockets)
    │              └ [<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 80)>]
    └ <bound method Server.run of <uvicorn.server.Server object at 0x109cd56a0>>
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/uvicorn/server.py", line 48, in run
    loop.run_until_complete(self.serve(sockets=sockets))
    │    │                  │    │             └ [<socket.socket fd=3, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('0.0.0.0', 80)>]
    │    │                  │    └ <function Server.serve at 0x10a4abca0>
    │    │                  └ <uvicorn.server.Server object at 0x109cd56a0>
    │    └ <function BaseEventLoop.run_until_complete at 0x10a205820>
    └ <_UnixSelectorEventLoop running=True closed=False debug=False>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/base_events.py", line 603, in run_until_complete
    self.run_forever()
    │    └ <function BaseEventLoop.run_forever at 0x10a205790>
    └ <_UnixSelectorEventLoop running=True closed=False debug=False>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/base_events.py", line 570, in run_forever
    self._run_once()
    │    └ <function BaseEventLoop._run_once at 0x10a209310>
    └ <_UnixSelectorEventLoop running=True closed=False debug=False>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/base_events.py", line 1859, in _run_once
    handle._run()
    │      └ <function Handle._run at 0x10a13ed30>
    └ <Handle <TaskWakeupMethWrapper object at 0x10bb75a60>(<_GatheringFu...in progress')>)>
  File "/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/events.py", line 81, in _run
    self._context.run(self._callback, *self._args)
    │    │            │    │           │    └ <member '_args' of 'Handle' objects>
    │    │            │    │           └ <Handle <TaskWakeupMethWrapper object at 0x10bb75a60>(<_GatheringFu...in progress')>)>
    │    │            │    └ <member '_callback' of 'Handle' objects>
    │    │            └ <Handle <TaskWakeupMethWrapper object at 0x10bb75a60>(<_GatheringFu...in progress')>)>
    │    └ <member '_context' of 'Handle' objects>
    └ <Handle <TaskWakeupMethWrapper object at 0x10bb75a60>(<_GatheringFu...in progress')>)>

> File "./xxx/xxx/xxx.py", line 144, in get_disclosure_data
    hh_json, db_json = await asyncio.gather(*coroutines)
                             │       │       └ [<coroutine object xxxx at 0x10bb2cb40>, <coroutine object db_call at 0x10bb2cc40>]
                             │       └ <function gather at 0x10a1fad30>
                             └ <module 'asyncio' from '/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/__init__.py'>

  File "./xxx/xxx/xxx.py", line 52, in db_call
    db_json = await asyncio.gather(*coroutines, loop=asyncio.get_event_loop())
                    │       │       │                │       └ <built-in function get_event_loop>
                    │       │       │                └ <module 'asyncio' from '/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/__init__.py'>
                    │       │       └ [<coroutine object DBConnectionManager.fetch_item at 0x10bb434c0>, <coroutine object DBConnectionManager.fetch_item at 0x10bb...
                    │       └ <function gather at 0x10a1fad30>
                    └ <module 'asyncio' from '/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/__init__.py'>

  File "./xxx/xxx/xx.py", line 97, in fetch_item
    await self._connection_pool.release(self.con)
          │    │                │       │    └ <PoolConnectionProxy [released] 0x10bbc9cd0>
          │    │                │       └ <chd_api.data.db.DBConnectionManager object at 0x10b946a30>
          │    │                └ <function Pool.release at 0x10b956a60>
          │    └ <asyncpg.pool.Pool object at 0x10bb131e0>
          └ <chd_api.data.db.DBConnectionManager object at 0x10b946a30>

  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/asyncpg/pool.py", line 666, in release
    return await asyncio.shield(ch.release(timeout))
                 │       │      │  │       └ None
                 │       │      │  └ <function PoolConnectionHolder.release at 0x10b952e50>
                 │       │      └ <asyncpg.pool.PoolConnectionHolder object at 0x10bb2a5c0>
                 │       └ <function shield at 0x10a1faee0>
                 └ <module 'asyncio' from '/Users/ddd/.pyenv/versions/3.8.6/lib/python3.8/asyncio/__init__.py'>
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/asyncpg/pool.py", line 218, in release
    raise ex
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/asyncpg/pool.py", line 208, in release
    await self._con.reset(timeout=budget)
          │    │                  └ None
          │    └ <member '_con' of 'PoolConnectionHolder' objects>
          └ <asyncpg.pool.PoolConnectionHolder object at 0x10bb2a5c0>
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/asyncpg/connection.py", line 1311, in reset
    await self.execute(reset_query, timeout=timeout)
          │    │       │                    └ None
          │    │       └ 'SELECT pg_advisory_unlock_all();\nCLOSE ALL;\nUNLISTEN *;\nRESET ALL;'
          │    └ <function Connection.execute at 0x10b93f3a0>
          └ <asyncpg.connection.Connection object at 0x10bc34120>
  File "/Users/ddd/Desktop/repos/xxx/.venv/lib/python3.8/site-packages/asyncpg/connection.py", line 297, in execute
    return await self._protocol.query(query, timeout)
                 │    │               │      └ None
                 │    │               └ 'SELECT pg_advisory_unlock_all();\nCLOSE ALL;\nUNLISTEN *;\nRESET ALL;'
                 │    └ <member '_protocol' of 'Connection' objects>
                 └ <asyncpg.connection.Connection object at 0x10bc34120>
  File "asyncpg/protocol/protocol.pyx", line 321, in query
    self._check_state()
  File "asyncpg/protocol/protocol.pyx", line 684, in asyncpg.protocol.protocol.BaseProtocol._check_state
    raise apg_exc.InterfaceError(
          │       └ <class 'asyncpg.exceptions._base.InterfaceError'>
          └ <module 'asyncpg.exceptions' from '/Users/ddd/Desktop/repos/chd-api/.venv/lib/python3.8/site-packages/asyncpg/exception...

asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress

我正在尝试使用以下命令执行大约22个数据库调用：

async def db_call(db, lat, lng):
    """
    Performs the necessary db calls given a lat, lng

    Required Input:
        lat::float a latitude in decimal degrees. Must be specified with `lng` (i.e. 39.2994)
        lng::float a longitude in decimal degrees. Must be specified with `lat` (i.e. -122.33)

    Returns:
        dict
    """
    coroutines = []
    for table in db_map:

        # SQL columns
        db_fields = ",".join(
            [
                f"{col} AS {db_map[table]['fields'][col]}"
                for col in db_map[table]["fields"]
            ]
        )

        # Output names
        api_fields = [db_map[table]["fields"][col] for col in db_map[table]["fields"]]

        if db_map[table]["query_type"] == "pip":
            limit = db_map[table]["options"]["LIMIT"]
            query = f"SELECT {db_fields} from {table} WHERE (ST_Covers(geom, GeomFromEWKT('SRID=4326;POINT({lng} {lat})'))) LIMIT {limit};"

        else:
            distance = db_map[table]["options"]["DISTANCE"]
            geo2geo = f"geom::geography, GeomFromEWKT('SRID=4326;POINT({lng} {lat})')::geography"
            query = (
                f"SELECT {db_fields}, ST_Distance({geo2geo})"
                f"from {table} WHERE (ST_DWithin({geo2geo}, {distance}))"
                f"ORDER BY ST_Distance({geo2geo}) LIMIT 1;"
            )

        coroutines.append(db.fetch_item(query))

    db_res = await asyncio.gather(*coroutines)
    
    .... code for processing results

---

我已经研究了asyncpg github上与此错误有关的几个问题，但仍然没有找到合适的解决方案。还要注意，这个调用是在FastAPI中执行的。请提供有关此错误发生原因/解决步骤的任何指导。

在

fetch\u item

中分配给

self.con

会导致多个协同程序共享同一连接。虽然您确实希望它们共享连接池，但共享同一个连接没有意义，因为该连接是有状态的

---

要解决此问题，请使用局部变量

con
替换
self.con
的用法。您是如何获得该回溯的？详细程度令人印象深刻。在
fetch_item
中分配给
self.con
的任务看起来可疑。您希望多个协同路由共享连接池，但不希望它们都共享同一个连接。用局部变量
con
替换
self.con
的用法，看看这是否有帮助。这就解决了问题。哇！给我一个正确的答案，我很高兴标记它接受！另外，细节来自loguru！很高兴听到这个消息，我现在把它作为一个答案发布了。
async def db_call(db, lat, lng):
    """
    Performs the necessary db calls given a lat, lng

    Required Input:
        lat::float a latitude in decimal degrees. Must be specified with `lng` (i.e. 39.2994)
        lng::float a longitude in decimal degrees. Must be specified with `lat` (i.e. -122.33)

    Returns:
        dict
    """
    coroutines = []
    for table in db_map:

        # SQL columns
        db_fields = ",".join(
            [
                f"{col} AS {db_map[table]['fields'][col]}"
                for col in db_map[table]["fields"]
            ]
        )

        # Output names
        api_fields = [db_map[table]["fields"][col] for col in db_map[table]["fields"]]

        if db_map[table]["query_type"] == "pip":
            limit = db_map[table]["options"]["LIMIT"]
            query = f"SELECT {db_fields} from {table} WHERE (ST_Covers(geom, GeomFromEWKT('SRID=4326;POINT({lng} {lat})'))) LIMIT {limit};"

        else:
            distance = db_map[table]["options"]["DISTANCE"]
            geo2geo = f"geom::geography, GeomFromEWKT('SRID=4326;POINT({lng} {lat})')::geography"
            query = (
                f"SELECT {db_fields}, ST_Distance({geo2geo})"
                f"from {table} WHERE (ST_DWithin({geo2geo}, {distance}))"
                f"ORDER BY ST_Distance({geo2geo}) LIMIT 1;"
            )

        coroutines.append(db.fetch_item(query))

    db_res = await asyncio.gather(*coroutines)
    
    .... code for processing results