[Zope] zope_msg.log Message

Cary O'Brien cobrien@Radix.Net
Sun, 26 Mar 2000 10:02:59 -0500 (EST)


> Pavlos Christoforou wrote:
> > 
> > On Fri, 24 Mar 2000, Michel Pelletier wrote:
> > 
> > >
> > > > As soon as I'm able to collect more info I'll forward it to you.  Is
> > > > there anywhere else I should be posting this information?
> > >
> > > The list.  just keep ccing me.
> > >
> > 
> > Some good news at last ...
> > 
> > When I set DEBUG in asyncore.py to 1 so I could view the lists going into
> > select, ZServer stabilised and hasn't crashed since. Smells like a race
> > condition and somehow the extra time it takes to print the list contents
> > stabilises things.
> 
> This might be a seperate problem than The Mysterious Segment Violation. 
> Can race conditions cause SEG faults? , I guess they can like any other
> piece of code.  but I would expect a race condition to just spin the
> process.  Can someone who I've spoken with about their SIGSEV problem
> reproduce Pavlos' cure?
> 

Wild idea: Do you ever get errors when you try to compile a big, big
program, specifically the Linux kernel?  It seems as if a large number
of seemingly perfectly functioning PCs have memory errors that only
show up under specific, not well known access patterns.  Compiling a
big program is a process that can exhibit these error prone
patterns[1][2].  Perhaps Zope under load causes the same access
patterns?

[1] This is not an urban legend.  I have seen it.
[2] Search for gcc and signal-11 or sigsegv.  There are a couple of
    web pages out there about this.

-- cary (probably wrong)

> > Still I cannot understand how the child process causes the supevising
> > (zdaemon) process to die too.
> 
> This makes me think it's a different problem also.  I get the feeling
> you should be able to reproduce this problem on a fresh checkout on your
> platform since it's so low level.  Can you check that?
> 
> -Michel
> 
> --__--__--
>