[Zope] Re: [Warning] Potential serious Session/TemporaryStorage problem

Dieter Maurer dieter at handshake.de
Wed Sep 1 16:55:39 EDT 2004


Dieter Maurer wrote at 2004-9-1 20:45 +0200:
> ...
>Recently, strange session related "Conflict Errors" have been reported.
>
>The strange thing about these conflicts is that the timestamp
>when the object was read from the ZODB is *AFTER* the timestamp
>the object has at commit time. Apparently, the object state
>jumped backward in time. When the object is modified, this
>results in a "ConflictError". However, when the object is only
>read, then old data is used -- probably without anyone noticing
>this.
> ...
>I will try to localize the place where this jumping backward in
>time happens.

The implementors of "ZODB.FileStorage.FileStorage.store"
and "tempstorage.TemporaryStorage.TemporaryStorage.store"
have simply been a bit confused about what is old and what is new:
the two values are interchanged: "was" is the serial at commit time,
"now" is the serial at load time. Thus, the "was serial" must be larger
than the "now serial".

-- 
Dieter


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