[ZODB-Dev] Re: BTrees strangeness (was [Zope-dev] Zope 2.X BIG Session problems - blocker - our site dies - need help of experience Zope developer, please)

[Chris McDonough]

On Tue, 2004-05-11 at 13:04, Dieter Maurer wrote:
> Hi Chris,
> 
> Chris McDonough wrote at 2004-5-11 00:54 -0400:
> > ...
> >So what do folks think of this error-case transaction isolation patch? 
> >Michael's original patch is preserved here (although it didn't survive
> >cut and paste from my mail client in a pristine way, you'll get the
> >idea):
> >
> >http://www.plope.com/Members/chrism/transaction_isolation_error.patch/file_view
> >
> >Personally it looks fine to me.  It wraps each error invocation in its
> >own transaction.
> 
> Please revisit the discussion (mostly between Toby and me) on
> "zope-dev" about how to fix this problem.
> 
> Toby convinced me that error handling should take place
> in the same transaction as the original request (and not in its
> own).
> 
> His main argument: the traceback can contain references to persistent
> objects that should not be there. If they are written to ZODB
> in any way, all kinds of dubious inconsistencies can occur.
> 
> Meanwhile, I saw several questions in the mailing lists of
> people that wanted to access the SESSION object during
> error handling (probably) because it contained useful information for
> error handling.
> This is impossible when the transaction is aborted before
> error handling.

Right.  I will try to work up another patch then.

- C