[ZODB-Dev] Shared/DC/ZRDB/TM.py:_register
Hi. _register method of TM class in Shared/DC/ZRDB/TM.py hides all exceptions. This makes descendants of this class prone to get stuck in a registered state withtout any possibility of them to get commited. To reproduce the problem: - create a class inheriting from TM, and define a method calling register. Add logs to abort and commit method to track transaction end. - create a default error page which triggers a call to the method created above. (this is equivalent to accessing some database from the error page, for example) Call it twice. Most realistic case is using an instance surviving the transaction (a global, or a persistant object) - tigger an error in TPC (a raise in vote is the most realistic case) and get the error page to render. The most obvious breakage I could see is when trying to undo an non-undoable transaction (modify a script twice, undo the oldest without undoing the newest) Here is what happens: - first transaction (the undo in my example) raises in TPC, transaction is marked as failed - error message gets rendered in the same transaction (that's a ZPublisher bug, but I think the problem root is hiding the failure) - error message tries to register itself to transaction manager: First try gets an exception (hidden in TM._register), but in the process transaction's _adapters dict was modified. TM subclass instance is not marked as registered. Second try, now there is no exception raised, because transaction's join is not called (because of _adapters content). Now the TM subclass instance is marked as registered, but unknown to transaction (_adapters will not be used to commit). The variant with just one call to TM._register only causes the instance to be commited at next transaction using it. Is there any reason why TM._register is hiding exceptions ? -- Vincent Pelletier ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Shared/DC/ZRDB/TM.py:_register
--On 13. Mai 2008 10:36:48 +0200 Vincent Pelletier [EMAIL PROTECTED] wrote: Hi. _register method of TM class in Shared/DC/ZRDB/TM.py hides all exceptions. This makes descendants of this class prone to get stuck in a registered state withtout any possibility of them to get commited. To reproduce the problem: - create a class inheriting from TM, and define a method calling register.Add logs to abort and commit method to track transaction end. - create a default error page which triggers a call to the method created above. (this is equivalent to accessing some database from the error page,for example) Call it twice. Most realistic case is using an instance surviving the transaction (a global, or a persistant object) - tigger an error in TPC (a raise in vote is the most realistic case) and getthe error page to render. The most obvious breakage I could see is whentrying to undo an non-undoable transaction (modify a script twice, undo theoldest without undoing the newest) Here is what happens: - first transaction (the undo in my example) raises in TPC, transaction ismarked as failed - error message gets rendered in the same transaction (that's a ZPublisherbug, but I think the problem root is hiding the failure) - error message tries to register itself to transaction manager: First try gets an exception (hidden in TM._register), but in the processtransaction's _adapters dict was modified. TM subclass instance is notmarked as registered. Second try, now there is no exception raised, because transaction's joinis not called (because of _adapters content). Now the TM subclass instanceis marked as registered, but unknown to transaction (_adapters will not beused to commit). The variant with just one call to TM._register only causes the instance to be commited at next transaction using it. Is there any reason why TM._register is hiding exceptions ? Isn't the right approach for integrating a module with ZODB transactions using a ZODB DataManager? Andreas pgpBTR1J9YUMG.pgp Description: PGP signature ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Shared/DC/ZRDB/TM.py:_register
--On 13. Mai 2008 20:08:15 +0200 Dieter Maurer [EMAIL PROTECTED] wrote: Andreas Jung wrote at 2008-5-13 10:44 +0200: ... Is there any reason why TM._register is hiding exceptions ? Isn't the right approach for integrating a module with ZODB transactions using a ZODB DataManager? Shared.DC.ZRDB.TM.TM is the standard Zope[2] way to implement a ZODB DataManager. Nowadays you create a datamanager implementing IDataManager and join it with the current transaction. Shared.DC.ZRDB.TM.TM is pretty much old-old-old-style. Andreas pgpJa88lGWbkd.pgp Description: PGP signature ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] Shared/DC/ZRDB/TM.py:_register
Andreas Jung wrote at 2008-5-13 20:19 +0200: ... Shared.DC.ZRDB.TM.TM is the standard Zope[2] way to implement a ZODB DataManager. Nowadays you create a datamanager implementing IDataManager and join it with the current transaction. Shared.DC.ZRDB.TM.TM is pretty much old-old-old-style. Time to change the Zope 2 code base ;-) There, you still find the old way -- and it is used by other Zope 2 components -- Dieter ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] ZODB 3.8.1b2 available and persistent caches
Hi Jim. Any chance of incorporating Shane's patch for relstorage for this release? Many thanks. Regards, David Jim Fulton wrote: Lately, we've started to use persistent caches. As we've done so, we've found and fixed a number of problems. I'm planning to make a 3.8.1 release soon. Jim -- Jim Fulton Zope Corporation ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
Re: [ZODB-Dev] ZODB 3.8.1b2 available and persistent caches
On May 13, 2008, at 4:44 PM, David Pratt wrote: Hi Jim. Any chance of incorporating Shane's patch for relstorage for this release? Many thanks. No. This is a bug fix release. Jim -- Jim Fulton Zope Corporation ___ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev
