[Zope] Zope - long running process

[R. David Murray]

On Sat, 12 Aug 2000, bak @ kedai wrote:
> > -----Original Message-----
> > From: zope-admin@zope.org [mailto:zope-admin@zope.org]On Behalf Of J.
> > Atwood
> >
> > There is a switch in z2.py that allows you to point to a PID file. It will
> > automatically restart your Zope installation once it goes down (if).
> 
> i've tried this, with 2.1.x and 2.2.0; but i'm not sure it works well.
> there are times when my zope hangs, and i need to stop and start manually.
> it may be my programming.  not too sure though.  what are others experience?

Under the unix source install, running with the monitor process active
is the default (if you remove the -D from the z2 startup command line).
I run this way with several sites, under both FreeBSD and Linux.  It
successfully restarts zope if it dies.  In certain unusual circumstances,
though, Zope will go into a spin where the python process consumes all
available CPU and Zope stops responding.  The monitor won't catch that.
(Someone wrote a script that will; search the archives).  In my experience
this happens, in 2.1.x, when certain conditions are met by the DTML
source code of referenced methods.  I'm not sure what the exact
conditions are, though I seem to recall they had to do with leading
whitespace and dtml code only at the start of the method.  I think
this bug was fixed in 2.2.

It *is* also possible to get Zope/python to spin through programming bugs.

--RDM