我正在尝试limit and limit_per_host参数为aiohttp.connector.TCPConnector.
在下面的脚本中，我通过connector = aiohttp.connector.TCPConnector(limit=25, limit_per_host=5) to aiohttp.ClientSession，然后打开 2 个对 docs.aiohttp.org 的请求和 3 个对 github.com 的请求。
的结果session.request是一个实例aiohttp.ClientResponse，在这个例子中我故意不调用.close()在其上，或者通过.close() or __aexit__。我假设这将使连接池保持打开状态，并将到该（主机、ssl、端口）的可用连接减少三倍-1。
下表代表._available_connections()每次请求后。为什么即使在完成对 docs.aiohttp.org 的第二次请求后，该数字仍停留在 4？这两个连接可能仍然打开并且尚未访问._content尚未或已关闭。可用连接不应该减少1吗？
After Request Num. To _available_connections
1 docs.aiohttp.org 4
2 docs.aiohttp.org 4 <--- Why?
3 github.com 4
4 github.com 3
5 github.com 2
此外，为什么._acquired_per_host只包含 1 个密钥？我想我可能正在理解的方法TCPConnector https://github.com/aio-libs/aiohttp/blob/master/aiohttp/connector.py;如何解释上述行为？
完整脚本：
import aiohttp
async def main():
connector = aiohttp.connector.TCPConnector(limit=25, limit_per_host=5)
print("Connector arguments:")
print("_limit:", connector._limit)
print("_limit_per_host:", connector._limit_per_host)
print("-" * 70, end="\n\n")
async with aiohttp.client.ClientSession(
connector=connector,
headers={"User-Agent": "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2225.0 Safari/537.36"},
raise_for_status=True
) as session:
# Make 2 connections to docs.aiohttp.org and
# 3 connections to github.com
#
# Note that these instances intentionally do not use
# .close(), either explicitly or via __aexit__
# in an async with block
r1 = await session.request(
"GET",
"https://docs.aiohttp.org/en/stable/client_reference.html#connectors"
)
print_connector_attrs("r1", session)
r2 = await session.request(
"GET",
"https://docs.aiohttp.org/en/stable/index.html"
)
print_connector_attrs("r2", session)
r3 = await session.request(
"GET",
"https://github.com/aio-libs/aiohttp/blob/master/aiohttp/client.py"
)
print_connector_attrs("r3", session)
r4 = await session.request(
"GET",
"https://github.com/python/cpython/blob/3.7/Lib/typing.py"
)
print_connector_attrs("r4", session)
r5 = await session.request(
"GET",
"https://github.com/aio-libs/aiohttp"
)
print_connector_attrs("r5", session)
def print_connector_attrs(name: str, session: aiohttp.client.ClientSession):
print("Connection attributes for", name, end="\n\n")
conn = session._connector
print("_conns:", conn._conns, end="\n\n")
print("_acquired:", conn._acquired, end="\n\n")
print("_acquired_per_host:", conn._acquired_per_host, end="\n\n")
print("_available_connections:")
for k in conn._acquired_per_host:
print("\t", k, conn._available_connections(k))
print("-" * 70, end="\n\n")
if __name__ == "__main__":
import asyncio
loop = asyncio.get_event_loop()
loop.run_until_complete(main())
输出粘贴在https://pastebin.com/rvfzMTe3 https://pastebin.com/rvfzMTe3。我把它放在那里而不是放在这里，因为线条很长而且不太容易折叠。
