[Zope] Zope stability

[Brian Lloyd]

> The question I'd like to raise to the entire list regards 
> Zope's stability.
>  We are running Zope
> integrated with Apache off FreeBSD3.2 .  As far as I know, 
> this is not such
> an exotic setup (probably 
> rather common?).  As Chas explained previously, Zope just 
> suddenly died.
> Teodore also had the same
> error occur and solved it by rebooting his server.  
> 
> How often has this occured with other people?  Are there any 
> good solutions
> regarding providing a backup
> in case Zope does die?  (and keep the site running) Are there 
> any serious
> Zope instability issues which 
> need to be discussed and alerted?

Obviously, any stability problems get the highest priority from 
us here at DC - if you don't look good, *we* don't look good :^)

We are _extremely_ interested in these "hanging" reports and 
would like to nail them down as quickly as possible so that 
we can address any issues internal to Zope and get a 2.1.1 
release out there if necessary. For folks that are seeing
these symptoms, you can help us speed the diagnosis by:

  o providing details on your environment (OS, version, zope 
    version in use). Have there been any recent changes in
    the environment?

  o symptom description - does CPU go to 100%? If so, does 
    there seem to be any pattern to the requests preceding
    the hang that you can determine (perhaps by looking at
    the server log)? Can you regularly reproduce it using
    a contrived test (like using ab or another benchmarking
    tool on a particular url or sequence of urls)? Does the
    problem happen only when accessing the system via pcgi
    or ZServer (or both)?

  o run in debug mode (using -D) and send any funny looking
    or unusual messages that you see

  o provide any unexplained tracebacks that you see from your 
    site

  o Look at the "debug" screen at Control_Panel/manage_debug.
    This can be used to spot memory leaks and stuck database 
    connections. If you think you may see something suspicious,
    save the document src and send it to us.

  o You can turn on more detailed logging by adding the following
    to your z2.py script:

    # turn on debug logging
    from ZServer import DebugLogger
    logfile=os.path.join(INSTANCE_HOME,'var/debug.log')
    DebugLogger.log=DebugLogger.DebugLogger(logfile).log

    It should be insertted after Zope is imported, e.g. after this line:

    exec "import "+MODULE in {}

    In particular, we want to look for requests that don't complete
    or for apparent leaking requests.


Thanks!


Brian Lloyd        brian@digicool.com
Software Engineer  540.371.6909              
Digital Creations  http://www.digicool.com