Re: [Lxr-general] apache (httpd) on f8 vs. fc6 running LXR

[Jan-Benedict G. <jb...@lu...>]

On Sun, 2008-02-24 20:20:22 -0500, Gene Smith <gd...@gm...> wrote:
> Jan-Benedict Glaw wrote, On 02/19/2008 06:57 PM:
> > On Mon, 2008-02-18 21:30:28 -0500, Gene Smith <gd...@gm...> wrote:
> > > Gene Smith wrote, On 02/03/2008 12:26 AM:
> > > > I have a LXR setup on fc6 that works fine. When I moved it to f8 (which 
> > > > seems to have the same versions of httpd, perl, mysql etc) I can only 
> > > > get it to work if I change the user/group in httpd.conf from 
> > > > apache:apache to myusername:myusername.  The files accessed by httpd, 
> > > > perl etc are world readable and executable but owned by root, as they 
> > > > were in fc6. These are in /usr/lib/perl5/site_perl/....
> > [...]
> > > To answer my own post, the reason was because the files accessed by lxr 
> > > were in my home directory with permission 700 and apache could not go 
> > > there. Pretty simple actually but not much hint from apache or lxr as to 
> > > what the problem was. Just was looking at the /home/me/lxr-file/ 
> > > directory which was set to 755, I think, but was was overriden by the 
> > > /home/me/ setting of 700. (Didn't realize the permission are inherited 
> > > but I guess they are.)
> > 
> > I hope you didn't need full two weeks to look at either strace output?
> > Were there no error messages in apache's error.log? No specific error
> > messages in HTTP output?
>
> Sorry, don't know much about strace. Didn't know it could be useful in 
> debugging my problem. Also, saw no errors in apache logs since I think 
> the "sources" script detected the error and generated OK html which just 
> said file not found. No permission denied or such messages.
> Actually, didn't take 2 weeks to fix, just didn't reply immediately.
> 
> Possibly you will say rtfm, but how do you use strace to debug lxr 
> problems (if I dare ask).

strace traces system calls, the border between userland programs and
the kernel. You can strace the whole apache processes from startup
(strace -f -ff -F -s 200 -o xxxxxxx /etc/init.d/apache start) or
attach to individual worker backends afterwards (-p PID).

Apache is one of the harder programs to properly strace, because it
does so much surrounding work, which all results in a lot of issued
system calls, bloating the logs. It's kind of an art to read those,
guessing what happens here and there :)  However, you won't really
notice suspicious stuff unless you're used to C programming.

MfG, JBG

-- 
      Jan-Benedict Glaw      jb...@lu...              +49-172-7608481
Signature of:              What we do for ourselves dies with us. What we do for
the second  :         others and the world remains and is immortal. (Albert Pine)