[ZODB-Dev] Re: [Zope-dev] Zope 2.5.0b4 problems w/ ZEO

[Matthew T. Kromer]

Andrew Sydelko wrote:

>Trying to start a ZEO client using Zope 2.5.0b4 doesn't
>work:
>
>------
>2002-01-15T20:13:20 INFO(0) client Trying to connect to server: ('192.168.1.52', 8900)
>------
>2002-01-15T20:13:20 INFO(0) ClientStorage Connected to storage
>------
>2002-01-15T20:13:20 ERROR(200) ZODB Couldn't load state for '\x00\x00\x00\x00\x00\x00\x00\x02'
>Traceback (innermost last):
>  File /data/www/Zope.8/src/Zope-2.5.0b4-src/lib/python/ZODB/Connection.py, line 471, in setstate
>TypeError: ('__init__() takes exactly 3 arguments (1 given)', <extension class Products.Sessions.SessionDataManager.SessionDataManagerTraverser at 88ba2f8>, ())
>
>------
>2002-01-15T20:13:20 PANIC(300) z2 Startup exception
>------
>2002-01-15T20:13:20 ERROR(200) ZODB Couldn't load state for '\x00\x00\x00\x00\x00\x00\x00\x02'
>Traceback (innermost last):
>  File /data/www/Zope.8/src/Zope-2.5.0b4-src/lib/python/ZODB/Connection.py, line 471, in setstate 
>TypeError: ('__init__() takes exactly 3 arguments (1 given)', <extension class Products.Sessions.SessionDataManager.SessionDataManagerTraverser at 88ba2f8>, ())
>
>Traceback (innermost last):
>  File /data/www/Zope.8/Zope/z2.py, line 495, in ?
>  File <string>, line 1, in ?
>  File /data/www/Zope.8/src/Zope-2.5.0b4-src/lib/python/Zope/__init__.py, line 71, in ?  
>  File /data/www/Zope.8/src/Zope-2.5.0b4-src/lib/python/OFS/Application.py, line 245, in initialize
>  File /data/www/Zope.8/src/Zope-2.5.0b4-src/lib/python/ZODB/Connection.py, line 471, in setstate
>TypeError: ('__init__() takes exactly 3 arguments (1 given)', <extension class Products.Sessions.SessionDataManager.SessionDataManagerTraverser at 88ba2f8>, ())
>
>------
>2002-01-15T20:13:21 PROBLEM(100) zdaemon zdaemon: Tue Jan 15 15:13:21 2002: The kid, 12557, died on me.
>
>
>Any ideas or suggestions?
>
>--andy.
>

Hi Andy,

in this particular case, ZEO is a red herring...  In beta 4 (and 
curiously, not on the HEAD--I'm sure I'll hear a "mea maxima culpa" soon 
from someone) the base class for the SessionDataManagerTraverser was 
made to be a persistent object.  Since the base class changed, the ZODB 
is now having fits trying to reconcile the change in base classes.

Since the session data manager object gets created automatically by Zope 
when it doesn't exist at system startup, you can make a new one (which 
inherits from Persistent) by:

1) Edit .../Products/Sessions/SessionDataManager and change the 
SessionDataManagerTraverser to not be persistent by duplicating the 
class line, commenting out one, and removing the Persistent word from 
the other

2) Restart Zope

3) Delete the session data manager from the root object

4) Stop Zope

5) Undo the editing change you did in step 1

6) Restart Zope

The problem will now have been addressed in the ZODB.  HOWEVER, since 
you mention you are running ZEO, all clients will have to have the same 
code base to be able to function.  You won't be able to do this without 
upgrading all of your code at the same time.