[Zope-dev] Zope instability problem

Tres Seaver tseaver@palladion.com
Thu, 20 Apr 2000 18:40:32 -0500


TFE WSD JARVIS JOHN <jarvis.sd082@ex.tel.co.jp>

Thank you for such a detailed description of the problem, and ways to reproduce
it.  Can you let us know the details of your Oracle setup (oracle version, which
OCI libraries you pick up, etc.)

Unless you object, I will clone your description over to the High-Availability
Zope wiki:

  http://www.zope.org/Members/tseaver/Projects/HighlyAvailableZope

BTW, I am assuming that the 'list_mon_detail' method sits on top of a ZSQL
Method -- is this correct?

Tres.

> 
> Hi all,
>   I've been having severe problems with Zope stability lately.
>   I wanted to provide a more detailed report, but I can't seem to find
> out what Zope is doing when it crashes--it seems completely
> random. I'd file a bug report, but I'm not sure exactly what to call a
> bug here or if there really is a bug and not just a bad setup on my
> part.
>   Well, here goes:
> 
> -- Zope drops connections to Oracle DB
> 
>   Based on what I saw with Zope 1, I thought that DB connections were
> persistent. Since moving to Zope 2, I've noticed that quite often the
> DB connections are lost. After watching the v$session table for a
> while, I noticed that when running a number of queries, Zope opens a
> number of connections equal to the number of Zope threads. When the
> traffic stops for a time (not long), these connections all
> disappear. Is this normal?
>   Often it seems that Zope can't reopen the connection and crashes or
> gives an error: "xxxx not connected to a database."
>   I thought maybe it was a setting on the DB side, but idle time, etc.
> is set for infinity for the Zope users. Also, this happens quite
> frequently under heavy use.
> 
> -- Zope crashes when using the [Open/Close Database Connection] button.
> 
>   Related to the above? Or is the above related to this?
>   Most often crashes after editing the connection properties or
> getting the "xxxx not connected to a database." error, noticing that
> the connection is marked as "Not Connected", and then clicking "Open
> Database Connection".
> 
> -- Zope crashes after heavy continued useage
> 
>   Feeling adventurous, I wrote a script that uses ZClient to request a
> query report page using random id's as search parameters. The script
> looks something like this:
> 
> --------begin script
> 
> from ZPublisher import Client
> from time import time, ctime
> from random import random
> 
> i = 0     # number or passes
> while 1:
>     i = i + 1
>     id = int(random()*1757) + 20000000
>     print "[" + ctime(time()) + "]", "Pass:", i, "No:", id
>     Client.call('http://appserver:8080/action/list_mon_detail?'
>                 'call_no='+id, 'anonymous', '')
> 
> ---------end script
> 
>   With Zope set for four threads and five instances of the script
> running on a different machine, Zope will silently crash within a half
> hour. ZDaemon restarts the process if it can, but no errors are
> reported (even in debug mode). I've also noticed that memory usage
> increases constantly until the crash. I still have gobs left, though.
>   I've noticed no difference in running through Apache/PCGI or Medusa.
>   A typical traceback looks something like this:

<traceback snipped> 

-- 
=========================================================
Tres Seaver  tseaver@digicool.com   tseaver@palladion.com