[Zope-dev] Conflict errors on startup, revisited

[Dieter Maurer]

Paul Winkler wrote at 2005-2-24 14:29 -0500:
>This is a topic that comes up occasionally, but since the symptom
>seems to be rare and hard to provoke, it never gets resolved.
>Well it's biting me again and I'm determined to fix it, but
>would like some input from the list.

I know that "ZopeProfiler" can cause such "ConflictError"s
and (what is more) why it does this.

"ZopeProfiler" (like some other products) wants to install
itself in "Control_Panel".

Because, this requires a database connection
and because "App.ProductContext.ProductContest" tries
hard to hide its application object,
"ZopeProfiler" opens a new one, modifies "Control_Panel"
and commits the transaction and then closes its connection.

Such modifications via a second ZODB connection
can cause unexpected (and puzzling) "ConflictError" on
startup.

The next "ZopeProfiler" version will access
"ProductContext.__app" instead (using the mangled name).

-- 
Dieter