From: Joel VanderWerf <vjoel@...>
Date: 2009-09-23T03:33:39+09:00
Subject: Re: Can't use a timeout with Socket::getaddrinfo

Ruby Nuby wrote:
> Does anyone know how to successfully implement a timeout with
> Socket::getaddrinfo?  This function works great against IP addresses
> that are resolvable.  In other cases where DNS can't find a hostname,
> getaddrinfo can act as a bottle neck.  In my script, all I'd really like
> to do is set a timeout to about 1 or 2 seconds, then simply move on if
> the IP cannot be resolved.  So I've tried something like this:
> 
> 
> timeout(2) {
> 
>    begin
>       puts "#{Socket::getaddrinfo(ARGV[0], "echo",
> Socket::AF_INET,Socket::SOCK_DGRAM)[0][2]}"
>    rescue(Timeout::Error)
>       puts "rescue has been reached"
>       puts ARGV[0]
>    end
> }
> 
> In this case, you'd expect that if DNS can't find the IP, it would time
> out in 2 seconds and reach the rescue.  Instead, it takes like 10 or 15
> seconds, then reaches the rescue.  I'd like to know why the rescue code
> is being reached if the timeout of 2 seconds isn't being used.  Also, is
> there a way for me to correctly implement a timeout on
> Socket:getaddrinfo?
> 
> Thanks in advance, fellow Rubyists.

Try resolv.rb in the standard library?

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407