Red Hat Bugzilla – Bug 73350
Slow DNS lookups for some sites
Last modified: 2007-03-26 23:56:43 EDT
Description of Problem:
By default, since RHL is an IPv6-capable system, APR passes AF_UNSPEC in the
getaddrinfo hints. For some sites, the DNS queries for the AAAA record
generated by getaddrinfo() are ignored and get no responses; this can be seen on
www.bloomberg.com, for instance, resulting in retries and timeouts before the A
record is attempted.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Add "ProxyRequests On" to default config + LoadModule lines for proxy
2. Configure browser to use server as proxy
3. Go to www.bloomberg.com
Page is very slow to load
Page is fast to load, as can be seen when not using the proxy
Daniel Stenberg (of curl fame) has a tip on how to avoid this: if
socket(AF_INET6, ...) fails, then just pass AF_INET in the getaddrinfo
hints rather than AF_UNSPEC, since the IPv6 module is not loaded.
A proper solution for this is possible in modern glibc; passing AI_ADDRCONFIG in
the getaddrinfo hints.