[Zope-dev] Signal 11 restarts

[Dieter Maurer]

Steve Alexander writes:
 > I have a Zope 2.4 CVS checkout from a couple of days ago, which I'm 
 > running on a linux system on a Cobalt Raq.
 > 
 > I've compiled it against Python 2.1.1 (compiled from source), and 
 > compiled a fresh DynPersist.so for it for use with ZPatterns.
 > 
 > Every so often, the server restarts after crashing on a signal 11.
 > 
 > The log entry looks something like this:
 > 
 > 2001-08-15T18:26:03 ERROR(200) zdaemon zdaemon: Wed Aug 15 19:26:03 
 > 2001: Aiieee! 8736 exited with error code: 11
You should be able to get a "core" dump.
Then, you would use a debugger to look into the "core".
With some luck, the problem is local and you can immediately
determine the culprit.

If bad cases, memory management has been hit. This is a non-local
problem, very difficult to analyse because the problem occured
much earlier...
A task for "purify" or similar tools...

I got today a signal 11 because I had used "getattr".
I am almost sure, this was caused by a runtime stack overflow.
Usually, Unix automatically extends the stack, but in
a multi-threaded program, this may not be possible -> Signal 11.


Writing core dumps is often disabled. With a bash, you can enable it
with:
		ulimit -c 20000

This would allow writing core files up to about 20 MB.


Dieter