[Zope-CMF] Replication And Workflows - "Nightmare of CMF Stre et"

[Norfleet, Sheppard S.]

Dietur,

Great tip!!!

I didn't know about the begin() method, but yeah I am doing a commit on end
and it seems to have been working ok.  I will put begin() in right away,
awesome!

Thanks again,

Shep
-----Original Message-----
From: Dieter Maurer [mailto:dieter at handshake.de]
Sent: Thursday, September 25, 2003 1:14 PM
To: Norfleet, Sheppard S.
Cc: 'zope-cmf at zope.org'
Subject: RE: [Zope-CMF] Replication And Workflows - "Nightmare of CMF
Stre et"


Norfleet, Sheppard S. wrote at 2003-9-25 08:34 -0700:
 > ...
 > >  *  I think Shane has a DCWorkflow variant that stores workflow
 > >     state outside the object.
 > >
 > >     Should you by chance use this variant?
 > 
 > Yes I do use DCWorkflow, but I previously reviewed the code and my
 > impression was that it was for the workflow content items, not the
workflow
 > tool, and its the workflow tool that seems to manage the workflow_history
 > attribute.  I see where DCWorkflow makes calls to the WorkflowTool
whenever
 > it needs state/history information.  So if my impressions are right how
can
 > it be managing the workflow_history outside of the object?  I will look
over
 > the code again...

You can quit this route.
Apparently, you do not have this special variant.

 > >  *  You mention separate threads.
 > >
 > >     Are you aware that a separate thread can easily read stale
 > >     data unless it plays well with the ZODB transaction
 > >     machinery?
 > >
 > >     Invalidation messages (caused by modification of objects)
 > >     are only handled at transaction boundaries.
 > >     Unless your separate thread commit/aborts the transaction
 > >     it is highly likely that it sees stale object state.
 > 
 > Yes, I defined a _p_independant function and bracketed transactions with
 > synchronization locks and have gotten rid of the ZODB conflict errors
that
 > plagued me for a long while.  I also refresh the DB connection on each
pass
 > by the replication thread in the hopes that it might combat stale data,
but
 > thats simply the tactics of a novice's mind.

And you have "get_transaction().begin()" at the start of the pass
and "get_transaction().commit()" or "...abort()" at its end?


Dieter