[Zope] Can multiple processes access a ZODB3 file?

[Kapil Thangavelu]

As Chris already stated (many times 4 effects:)

ZODB is process locked.

The question than becomes what kind of process interaction do you want
with the zodb. most everything can be done by having hooks into zope and
interacting with those hooks from your external python process. examples
are a cronned mail script that checks emails and sends them into zope,
an external document retrieval system that grabs new docs and sits them
on a file system or inserts into ZODB via hooks, a python zope product
that gives a corba interface to selected zope objects... basically
anything python can touch. if you're python process needs to be more
intimate with the zodb than it might require a bit more planning. what
were you trying to do?

generally for external interactions i use xml-rpc (if the data sets
aren't huge), but you could also script a monitor session.

Kapil

Ross Boylan wrote:
> 
> If I have Zope running, using ZODB3 on Data.fs, can a separate
> process also use ZODB3 to access Data.fs?  I have my suspicions, but
> I'm not sure.
> 
> I'm interested in this because I'm in the middle of a balloting
> period.  People email me their ballots.  I will need to check them
> for validity, send out confirmation or error messages, and eventually
> tally the results.
> 
> I definitely want a persistent store, so ZODB seems good.  Also, I
> eventually would like this to be a Zope product, with people able to
> access the results on the web (and, in the future, vote on the web).
> But getting it Zoped may be too much work in the short run.
> 
> So, I'll have a Zope server running on my Debian system, and another
> process will be going through the mail.  It would be more
> straightforwad if that other process worked directly with the
> database, rather than going through Zope via http or xml-rpc or
> something similar.  So I'm wondering if that's possible.  I can
> always take the indirect route if, as I suspect, that's necessary.
> 
> I'm cribbing from parts of the Poll product as appropriate.  The
> polling machinery is considerably more complex though: a restricted
> list of voters, various muckings around to get the info out of the
> email, and preference voting (1 for first choice, 2 for second, etc
> with an instant run off).
> 
> I know Zeo is more in the multi-process space, but I don't want to
> use it for this project because I don't have time to learn it; it's
> alpha; and it seems like overkill for my problem.
> 
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