带有 aiohttp 的 asyncpg 连接池引发 asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress答案

【问题标题】：asyncpg Connection pool with aiohttp raise asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress带有 aiohttp 的 asyncpg 连接池引发 asyncpg.exceptions._base.InterfaceError: cannot perform operation: another operation is in progress
【发布时间】：2022-10-15 05:28:39
【问题描述】：

当我尝试使用文档中的 aiohttp 重现 example 时我得到错误：

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

当应用程序在任何添加的路由上获取 GET 请求时引发异常。

这是我的代码：

import asyncio
import asyncpg
from aiohttp import web


async def handle(request):
    """Handle incoming requests."""
    pool = request.app['pool']
    power = int(request.match_info.get('power', 10))

    # Take a connection from the pool.
    async with pool.acquire() as connection:
        # Open a transaction.
        async with connection.transaction():
            # Run the query passing the request argument.
            result = await connection.fetchval('select 2 ^ $1', power)
            return web.Response(
                text="2 ^ {} is {}".format(power, result))


async def init_app():
    """Initialize the application server."""
    app = web.Application()
    # Create a database connection pool
    app['pool'] = await asyncpg.create_pool(
        host="DB_HOST",
        port=5432,
        user="DB_USER",
        password="DB_PASSWORD",
        database="DB_NAME",)
    # Configure service routes
    app.router.add_route('GET', '/issues', handle)
    app.router.add_route('GET', '/', handle)
    return app


loop = asyncio.get_event_loop()
app = loop.run_until_complete(init_app())
web.run_app(app, port=8800)

如果我使用 PgBouncer，我会得到相同的结果

【问题讨论】：

标签： python postgresql asyncpg connection-pool

【解决方案1】：

我找到了一个解决方案：

它需要在run_app 方法中将循环作为参数传递

...
web.run_app(app, port=8800, loop=loop)

【讨论】：