python network_error ai_generated true

aiohttp.client_exceptions.ClientConnectorDNSError: Cannot resolve hostname example.com

ID: python/aiohttp-client-connector-resolver-error

Also available as: JSON · Markdown · 中文
80%Fix Rate
83%Confidence
0Evidence
2025-03-05First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.10 active — — —
3.11 active — — —

Root Cause

DNS resolution failed for the given hostname, possibly due to network issues or invalid domain.

generic

中文

给定主机名的 DNS 解析失败，可能是由于网络问题或无效域名。

Workarounds

  1. 85% success Check DNS configuration and use a custom resolver 
    from aiohttp.resolver import AsyncResolver
resolver = AsyncResolver(nameservers=['8.8.8.8', '8.8.4.4'])
connector = aiohttp.TCPConnector(resolver=resolver)
async with aiohttp.ClientSession(connector=connector) as session:
  2. 80% success Implement retry with DNS fallback 
    import socket
try:
    socket.gethostbyname('example.com')
except socket.gaierror:
    # fallback to IP or alternative hostname

Dead Ends

Common approaches that don't work:

  1. Using IP address directly instead of hostname 50% fail

    IP addresses may change, and SSL certificates may not match, causing other errors.

  2. Adding a custom hosts file entry without proper validation 40% fail

    The entry may be incorrect or overridden by system settings.