On Mon, 29 Mar 2004, Roy Shan wrote:

> In my prototype system, I use the python interface, pycurl. I have upgraded
> to the latest 7.11.1 version. Multi interface is used and Ares support is
> enabled. The development is quite easy. However, I am facing a strange
> problem: some handles get stuck in name resolve and never come out.
> According to debugging info, the connection time and total time of those
> dead handles are all zero. If I disable Ares support, the problem seems to
> be gone.

Given all that, it certainly sounds like either a pure ares-bug or (more
likely) a libcurl bug when it uses ares.

> After checking pycurl code, I don't think it's a problem in the python
> wrapper. So I wonder if it's a bug in libcurl. Because I am doing a lot of
> dns query, the dns server can be busy and drop some queries. In that case,
> what does libcurl do? Can it time-out? I looked into libcurl code and didn't
> see anything wrong so far.

Hm. I think you're on to something. I can't see that we ever timeout the
CURLM_STATE_WAITRESOLVE state unless ares returns an error at some point.
Curl_is_resolved() is simply called and that just calls ares to keep on
processing.

Can you make some kind of debug output to see if the stuck handles are in this
state when they stall?

-- 
     Daniel Stenberg -- http://curl.haxx.se -- http://daniel.haxx.se
      Dedicated custom curl help for hire: http://haxx.se/curl.html