httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jeff Trawick <>
Subject Re: error log providers, multiple vhosts, mod_syslog
Date Thu, 07 Nov 2013 18:07:19 GMT
On Thu, Nov 7, 2013 at 7:09 AM, Jan Kaluža <> wrote:

> On 11/07/2013 11:11 AM, Joe Orton wrote:
>> On Thu, Oct 17, 2013 at 12:33:50PM +0000, Plüm, Rüdiger, Vodafone Group
>> wrote:
>>> Hmm. This points out another issue when using an error log provider for
>>> the main server log:
>>> We lose everything that the server or other programs like CGI-scripts
>>> write to the stderr FD as it
>>> is simply written to /dev/null. Don't we need to have a separate process
>>> in this case that
>>> like a piped logger reads from the reading end of the "stderr pipe" and
>>> writes it
>>> via ap_server_conf->errorlog_provider->writer to the log?
>> Jumping in here...
>> Actually there should be few cases where modules write to stderr, no?
>> I'm not sure we should even consider "writes to stderr get logged" a
>> valid part of the module API.  "If you're not using ap_log_*error,
>> you're out of luck" is not totally unreasonable.
>> mod_cgi does intercept stderr and logs it properly via ap_log_rerror,
>> and mod_cgid does stderr logging differently anyway.
>> One case which is common is the use of apr_procattr_child_errfn_set() to
>> write exec() errors to stderr after forking a child.  But perhaps we
>> could and should provide a single common implementation of that which
>> does something more useful.
>> With "ErrorLog syslog" in current 2.x (and 1.3?), stderr is /dev/null
>> already, so the status quo is that we lose stuff, though that is kind of
>> ugly.
> Reading this I think I could commit my httpd-trunk-stderr-provider.patch
> from older email in this thread. It does not fix stderr logging, but it
> fixes httpd-trunk problem where messages with NULL server_rec* are not
> logged.
> I'm attaching better version of that patch here (it fixes potential crash
> pointed out by Rüdiger when both logf and error_log_provider are NULL).
> If anyone is against it or has better idea how to fix logging of messages
> with NULL server_rec* when log providers are used, tell me.

Is the observation about NULL server_rec for modules that weren't updated
properly to pass ap_server_conf when no server_rec was available, or for
some window where ap_server_conf is NULL but server_rec is needed?

>  Regards, Joe
> Regards,
> Jan Kaluza

Born in Roswell... married an alien...

View raw message