[Zope-DB] DA's violating transactional assertions
Tue, 28 Jan 2003 11:32:55 +0100
Dieter Maurer wrote:
> Federico Di Gregorio wrote at 2003-1-24 10:27 +0100:
> > Il ven, 2003-01-24 alle 04:12, Robert Kellock ha scritto:
> > > Which ones?
> > ZpsycopgDA for sure (right Dieter? :) and probably ZOracleDA (from which
> > ZPsycopgDA was derived), ZPoPyDA and maybe even the mysql adapter (but i
> > can be wrong here.)
> > i completely agree with Dieter's analisys and i'll try to fix the
> > problem in the 1.1 series. the problem is: does zope provides such a
> > "special exception"?
> The "retry" logic is implemented in "Zope/__init__.py:zpublisher_exception_hook".
> As it is, it retries on any subclass of "ZODB.POSException.ConflictError".
> Of course, when it really were necessary, it could be extended.
> But, the current case would not make this necessary.
> The DA could simply derive an appropriate exception
> from "ZODB.POSException.ConflictError" and use that
> for its transient errors.
> We may get cleaner code across DA's when we define a standard
> DATransientError. It should clearly state, which DA instance (path)
> got the problem and what was the original exception (which
> we converted into a "DATransientError").
> On alternative to such an information rich exception would
> be to log the original exception (not a bad idea anyway).
Then let's do both: log the event and raise a ConflictError
Does Zope have means to prevent an endless loop here ? E.g.
in case the OperationalError raised by the database was not
really caused by a lost connection.
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