Re: [Zope] A question about __setstate__ in Shared/DC/ZRDB/Connection.py
Marco Bizzarri wrote at 2008-9-20 08:41 +0200: ... I'm working right now with Zope 2.8, which I don't think is running on that version of ZODB; is is possible to backport such patch to Zope 2.8? I'm not asking to do the work, I'm just asking if, in theory, it is possible to do it, or if it relies on something which has been introduced in new releases of ZODB. Sure. The proposal is age old -- and we are using the implementation since years -- also in Zope 2.8. It is a bit more difficult for me to provide a clean patch for the feature against a stock Zope 2.8 -- as beside this, we have many other modications/improvements and it is not easy to separate them. -- Dieter ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] A question about __setstate__ in Shared/DC/ZRDB/Connection.py
Marco Bizzarri wrote at 2008-9-19 09:23 +0200: ... I assume therefore that the ZPsycopgDA object has been ghostified, during the transaction. But this assumption is not supported by any evidence. In particular, it is not supported by my knowledge of the internal behaviour of ZODB on objects during a single transaction. Can anyone provide suggestion on this topic? Cache garbage collection can happen at savepoint time. Then, volatile attributes can be lost. There is an age old proposal http://wiki.zope.org/ZODB/VolatileAttributeLifetimeGarantee; which would allow to avoid this problem. As we use this feature since ages in our local Zope/ZODB version, I could provide an implementing patch (for ZODB 3.8). -- Dieter ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
Re: [Zope] A question about __setstate__ in Shared/DC/ZRDB/Connection.py
On Sat, Sep 20, 2008 at 8:21 AM, Dieter Maurer [EMAIL PROTECTED] wrote: Marco Bizzarri wrote at 2008-9-19 09:23 +0200: ... I assume therefore that the ZPsycopgDA object has been ghostified, during the transaction. But this assumption is not supported by any evidence. In particular, it is not supported by my knowledge of the internal behaviour of ZODB on objects during a single transaction. Can anyone provide suggestion on this topic? Cache garbage collection can happen at savepoint time. Then, volatile attributes can be lost. There is an age old proposal http://wiki.zope.org/ZODB/VolatileAttributeLifetimeGarantee; which would allow to avoid this problem. As we use this feature since ages in our local Zope/ZODB version, I could provide an implementing patch (for ZODB 3.8). -- Dieter I'm working right now with Zope 2.8, which I don't think is running on that version of ZODB; is is possible to backport such patch to Zope 2.8? I'm not asking to do the work, I'm just asking if, in theory, it is possible to do it, or if it relies on something which has been introduced in new releases of ZODB. Regards Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
[Zope] A question about __setstate__ in Shared/DC/ZRDB/Connection.py
Hi all. I'm working on an application which uses Zope (2.8, at the moment) and ZPsycopgDA (toghter with a number of other products). While writing an acceptance test, I encountered a strange problem: the test locks up. A further investigation shown that there were two connections at the database; one of them was not committed, the other one was blocked waiting for the other to commit. I therefore used the pdb in order to stop the execution of the test inside the connect method of the ZPsycopgDA.DA. Once I had that breakpoint, I was able to get the logs of the two transactions on the database, and I had the confirmation that indeed there were two different transactions. So, I wondered what could possibily happen, I mean why during a test there could be a second connect to the database. I issued a bt to see the stack of calls leading to the connect, and what I could see was that the coonect was called inside the __setstate__ method of Shared/DC/ZRDB/Connection.py. I assume therefore that the ZPsycopgDA object has been ghostified, during the transaction. But this assumption is not supported by any evidence. In particular, it is not supported by my knowledge of the internal behaviour of ZODB on objects during a single transaction. Can anyone provide suggestion on this topic? Regards Marco -- Marco Bizzarri http://notenotturne.blogspot.com/ http://iliveinpisa.blogspot.com/ ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
