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Re: libcurl 8.16.0 spawning large number of getaddrinfo threads?

From: Vadim Grinshpun via curl-library <curl-library_at_lists.haxx.se>
Date: Mon, 20 Oct 2025 13:15:16 -0400

On 10/20/25 12:58 PM, m brandenberg via curl-library wrote:
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> On Mon, 20 Oct 2025, Vadim Grinshpun via curl-library wrote:
>
>> I'll look into enabling c-ares. In another part of this thread,
>> Daniel mentioned that c-ares can behave differently from getaddrinfo;
>> are known differences documented somewhere? (I'd like to ensure we
>> won't get affected).
>
> Personal anecdote as this fell out of one of the weirdest debugging
> sessions I've ever had.  On certain windows machines with various
> add-ons installed, correct DNS responses would come in on interfaces
> other than that on which the request had been sent.  This would trigger
> some anti-poisoning defenses in c-ares completely defeating lookup in
> the application.  This was several years ago - c-ares may have relaxed
> since then.
>
Thanks :)

(I should've mentioned that I'm only concerned about Linux, other
platforms are not relevant for my use case)


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Received on 2025-10-20