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Re: DNS Cache

From: brubelsabs <>
Date: Fri, 08 Aug 2008 11:00:36 +0200

Daniel Stenberg wrote:
> On Thu, 7 Aug 2008, brubelsabs wrote:
>> the problem is, that already in the second wave more than 300 requests
>> are marked as "COULDN'T RESOLVE HOST NAME" (CURL_ERROR 6) despite they
>> are resolvable actually!
> So you have no problems with 299 requests, but you have problems with
> 300 and more?

no, I encounter these problems with more than 1000 requests (starting at
the second wave), then >300 will fail. This means the first wave with
1000 will always pass, then the second wave (with also 1000 req.) will
always encounter problems more than 300 will fail. With more than 2500
req. in the first wave some of them will always fail. Its unfortunately
not that predictable and deterministic so I can say with "299" its
working and with "300" it's not. I could mail you the code if you want
to, to have a look on this.

> When you get the problems, have you tried to strace or gdb to figure out
> exactly what it is that fails?

All seems as libcurl delivers just a network error unfortunately I have
only very very gdb basics which I could apply. It seems as just theses
URLs weren't resolvable. I tried also a different Nameserver (OpenDNS)
but this redirects to search-results for the requested domain instead of
delivering the message that he can't resolve the domain name.

thanks for your help
Received on 2008-08-08