Re: mod_perl-2.0.2 causing segfaults

[Fred Moyer <suppressed>]

On Mon, 11 Dec 2006, Grant wrote:

> > > > > > >   Also, I tried restarting the interchange daemon with
> > > > > > >   PERL_SIGNALS=unsafe and the ALERT/segfaults came MUCH MUCH more
> > > > > > >   frequently.  Does that tell us anything?
> > > > > > 
> > > > > > 
> > > > > >   It would make sense that, when you have high load, there is a 
> > > > > >   problem
> > > > > >   processing many concurrent requests which triggers the PIPE 
> > > > > >   signal, so
> > > > > >   you should find out what the error is, and handle it more 
> > > > > >   gracefully.
> > > > > > 
> > > > > >   You might want to change the die sub to print out $! and $? - 
> > > > > >   that may
> > > > > >   give you a bit of a clue as to what caused the PIPE signal.
> > > > > > 
> > > > > >   I'm guessing (and it is a guess) that the segfaults may be caused
> > > > > >   because the die sub sends a web response, but that sub could be 
> > > > > >   called
> > > > > >   while your server is busy doing something else, and the two 
> > > > > >   actions
> > > > > >   collide.
> > > > > 
> > > > >   Very good guess.  Commenting out the web response stuff seems to 
> > > > >   have
> > > > >   eliminated the segfaults.  Adding $! and $? to the warn line, I'm
> > > > >   getting one of these two bits along with each ALERT now:
> > > > > 
> > > > >   Broken pipe 0
> > > > >   Inappropriate ioctl for device 0
> > > >  This could happen from a Cntrl-C or stop in a browser.
> > > > 
> > > >  Add
> > > >  require Carp;
> > > >  Carp::cluck() to your die() function.
> > > 
> > >  Is this someplace that checking $r->connection->aborted() would be 
> > >  useful?
> >
> >  Would I just add "$r->connection->aborted()" without the quotes to the
> >  warn line?
>
> If I do change the warn line to:
>
> warn "ALERT: bad pipe signal received for $ENV{SCRIPT_NAME} $! $?
> $r->connection->aborted()\n";

try

  warn "ALERT: bad pipe signal received for $ENV{SCRIPT_NAME} $! $? "
      . $r->connection->aborted . "\n";

> I get:
>
> ALERT: bad pipe signal received for / Broken pipe 0
> Apache2::RequestRec=SCALAR(0x16eef638)->connection->aborted()
>
> Any help with that or Carp::cluck implementation would be greatly 
> appreciated.
>
> - Grant