Using getaddrinfo_a on configuration load

[Cyrus Hall]

Hi!

I've searched the list and not found much on lengthy HAProxy 
start/config load times.  We tend to run HAProxy with a large number of 
backends (100+), and recently noticed that we are seeing lengthy reload 
times (20+ seconds).  This is most noticeable in locations that are far 
away from our DNS server.  We've traced this back to HAProxy doing 
sequential DNS lookup, one address at a time, and the long RTT to our 
DNS servers (~200ms).  As such, load times tend to be N*M ms, where N is 
the number of backends and M is the RTT to the DNS server.

While searching the mailing list, there was a little discussion about 
using getaddrinfo_a for making DNS queries asynchronous.  I can not find 
any signs of this work in the latest development branch release.  Is 
anyone currently working on it, and if not, is it something that the 
project would be interested in seeing?

Cheers,
Cyrus

--

Cyrus Hall | Lead Software Engineer | Twitch | 720-327-0344 | 
cy...@twitch.tv