cURL / Mailing Lists / curl-library / Single Mail


Re: Strange "couldn't connect to host" error

From: Jonathan Arnold <>
Date: Thu, 31 May 2007 16:45:35 -0400

Dan Fandrich wrote:
> On Thu, May 31, 2007 at 03:42:30PM -0400, Jonathan Arnold wrote:
>> We have a routine that gets called every second, goes out to the web,
>> and downloads a tiny (about 50 characters) file. It runs okay for
>> some random time, say 30 minutes, but then returns back a "Couldn't
>> connect to host" error. If I stop it in the debug, and move back the
>> current statement and just retry the Curl_PerformHttp call, it
>> works just fine. This is on Windows (XP in my case). The timer code
>> is pretty straightforward:
> Could it be that your web server is legitimately refusing connections? It's

I doubt it, as it is an error only a few see (like myself).

> possible (though a bit unlikely) that it sees so many connections as a
> potential DOS and is denying access occasionally. Or perhaps it's hitting
> a limit on the number of new connections in a short period. Try tweaking
> the server settings and see if the problem is fixed. Are you using
> persistent connections?

Yes, I'm using persistent connections, and re-using the same curl handle.

Jonathan Arnold           Software Engineer
inSORS Integrated Communications, Inc Office/fax: 781.391.2818
Received on 2007-05-31