[ZODB-Dev] Advanced ZODB for Python Programmers article: volatile example

2010-05-24 Thread Vincent Pelletier
Hi. I think the example on volatile attributes given in Advanced ZODB for Python Programmers article[1] shows a bad practice. From the article: if hasattr(self, '_v_image'): return self._v_image This should be rewritten as: try: return self._v_image except

Re: [ZODB-Dev] Advanced ZODB for Python Programmers article: volatile example

2010-05-24 Thread Vincent Pelletier
Le lundi 24 mai 2010 12:02:40, Wichert Akkerman a écrit : which prevents the exception overhead. Right, thought this is a tradeoff question: writing as exception handling is faster for volatile is present case, but slower for volatile is missing case. -- Vincent Pelletier

[ZODB-Dev] ClientDisconnected with ZEORaid

2010-05-24 Thread Dylan Jay
Hi, I've been testing out ZEORaid and it seems to work fine in itself, but ZODB client connections seem to be getting into a ClientDisconnected state and never getting out. Zope has a main ZEORaid to connect to and several fallbacks. Most of the time when it's connection is dropped it

Re: [ZODB-Dev] Notes on using wrapper storages for record transformation

2010-05-24 Thread Vincent Pelletier
Le dimanche 23 mai 2010 16:11:44, Jim Fulton a écrit : I'm not sure what you mean by object level locks. I've been planning to add something similar to object-level locks during the commit process, so multiple transactions can be doing commit-related activity at once. That's the feature I

[ZODB-Dev] Conflict resolution (was Re: Notes on using wrapper storages for record transformation)

2010-05-24 Thread Jim Fulton
On Mon, May 24, 2010 at 10:57 AM, Vincent Pelletier vinc...@nexedi.com wrote: Le dimanche 23 mai 2010 16:11:44, Jim Fulton a écrit : Getting a bit more out of initial topic: I am currently searching for papers describing how conflict resolution is supposed to happen, and more exactly if it is

Re: [ZODB-Dev] Conflict resolution (was Re: Notes on using wrapper storages for record transformation)

2010-05-24 Thread Vincent Pelletier
Le lundi 24 mai 2010 17:23:54, Jim Fulton a écrit : Reference? Weak Consistency: A Generalized Theory and Optimistic Implementations for Distributed Transactions http://pmg.csail.mit.edu/pubs/adya99__weak_consis-abstract.html If we do conflict resolution before the commit lock is held, then

Re: [ZODB-Dev] Conflict resolution (was Re: Notes on using wrapper storages for record transformation)

2010-05-24 Thread Jim Fulton
On Mon, May 24, 2010 at 3:03 PM, Vincent Pelletier vinc...@nexedi.com wrote: Le lundi 24 mai 2010 17:23:54, Jim Fulton a écrit : Reference? Weak Consistency: A Generalized Theory and Optimistic Implementations for Distributed Transactions