[ZODB-Dev] Competing WRITES while viewing a Managment Screen?!

Chris McDonough chrism@zope.com
Wed, 29 Aug 2001 08:32:00 -0400


This is a read conflict.  Essentially it means that you've read data in 
one connection after it has been modified in another.

Any further questions on this topic will likely be met with a slow 
drool.  ;-)

Chris Withers wrote:
> Hi,
> 
> Here's the situation:
> 
> - Zope 2.4.0
> - ZEO 1.0b4
> 
> 1. ZEO client being used to load large numbers of File objects into a
> BTreeFolder
> 2. ZEO client being used to develop a Python Product for use on another section
> of the site.
> 
> VIEWING the management screens on the second client gave me the traceback in the
> ps in the logs.
> 
> What gives?! I'm asking here 'cos the error is originating from Connection.py
> and you guys seem to know lots about that ;-) Also, I remember a thread on
> something similar not that long ago...
> 
> cheers,
> 
> Chris
> 
> PS:
> 
> ------
> 2001-08-29T08:10:02 INFO(0) Z2 CONFLICT Competing writes at, /manage_menu
> Traceback (innermost last):
>   File E:\Zope\2471A4~1.0\lib\python\ZPublisher\Publish.py, line 171, in publish
> 
>   File E:\Zope\2471A4~1.0\lib\python\ZPublisher\mapply.py, line 160, in mapply
>     (Object: manage_menu)
>   File E:\Zope\2471A4~1.0\lib\python\ZPublisher\Publish.py, line 112, in call_ob
> ject
>     (Object: manage_menu)
>   File E:\Zope\2471A4~1.0\lib\python\Shared\DC\Scripts\Bindings.py, line 324, in
>  __call__
>     (Object: manage_menu)
>   File E:\Zope\2471A4~1.0\lib\python\Shared\DC\Scripts\Bindings.py, line 354, in
>  _bindAndExec
>     (Object: manage_menu)
>   File E:\Zope\2471A4~1.0\lib\python\App\special_dtml.py, line 241, in _exec
>     (Object: manage_menu)
>   File E:\Zope\2471A4~1.0\lib\python\TreeDisplay\TreeTag.py, line 159, in render
> 
>     (Object: a tree tag)
>   File E:\Zope\2471A4~1.0\lib\python\TreeDisplay\TreeTag.py, line 269, in tpRend
> er
>     (Object: ApplicationDefaultPermissions)
>   File E:\Zope\2471A4~1.0\lib\python\TreeDisplay\TreeTag.py, line 523, in tpRend
> erTABLE
>     (Object: ApplicationDefaultPermissions)
>     (Info: (['AAAAAAAAAAE=', []], {'childless_decoration': '', 'id': 'tpId', 'br
> anches': 'tpValues', 'nowrap': '1', 'url': 'tpURL'}, (['AAAAAAAAAAE=', []],), ([
> 'AAAAAAAAAAE=', []],)))
>   File E:\Zope\2471A4~1.0\lib\python\TreeDisplay\TreeTag.py, line 323, in tpRend
> erTABLE
>     (Object: LockableItem)
>   File E:\Zope\2471A4~1.0\lib\python\OFS\ObjectManager.py, line 517, in tpValues
> 
>     (Object: LockableItem)
>   File E:\Zope\instance\Products\BTreeFolder\BTreeFolder.py, line 177, in _getOb
> 
>     (Object: LockableItem)
>   File E:\Zope\2471A4~1.0\lib\python\ZODB\Connection.py, line 535, in setstate
> ConflictError: ("'\\x00\\x00\\x00\\x00\\x00\\x00\\xe6\\xb7'", '<extension class
> BTree.Bucket at 013C5280>')
> 
> _______________________________________________
> For more information about ZODB, see the ZODB Wiki:
> http://www.zope.org/Wikis/ZODB/
> 
> ZODB-Dev mailing list  -  ZODB-Dev@zope.org
> http://lists.zope.org/mailman/listinfo/zodb-dev
> 


-- 
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"