blocked DNS query

David Botham DBotham at
Mon Nov 29 17:03:27 UTC 2004

bind-users-bounce at wrote on 11/29/2004 10:16:42 AM:
> On Mon, Nov 29, 2004 at 10:01:46AM -0500,
>  kaiduan xie <kaiduanx at> wrote 
>  a message of 53 lines which said:
> > Actually there is a resolver library ARES from MIT.
> OK, so you actually have a question about the use of the ARES library,
> not about BIND or about the DNS. Correct?
> > The gethostbyname() call is synchrous.
> gethostbyname has been deprecated in the last century :-) See "man
> getaddrinfo" or RFC 3493.
> > I want to know the case where from the user's point of view, the DNS
> > query is blocked.
> I'm afraid I do not understand more this time. It seems a very
> ARES-specific question and I never used this library.

The OP is asking about blocking as it pertaints to IO in a programming 
sense.  Something is said to block if it waits for a response.  Things 
that block tend to bog the system down (from what little I understand on 
the subject).



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