[ZODB-Dev] read-only database

[Nathan Van Gheem]

> Can you rephrase that with fewer "not"s?  I'm not quite sure what you're
> asking...
:) Yes. We would like our read-only zodb to still serve pages even if
plone tries to write to the database. Basically, we'd like to suppress
the read-only errors you get when you try to write to a read-only
database.

> It would be much safer to fix Zope/Plone application than to monkey
> around with silently working around the readonly aspects of the
> database. especially since you are already putting the database
> into a readonly mode.
> again, we are doing this fine in production.  so it must be something
> in your application causing writes.
We've seen issues where a scale wasn't generated for some reason,
archetypes trying to write a field value when calling the get
accessor, writes occurring when simply calling context.objectValues()
and other ones I haven't figured out yet. They aren't on a majority of
the pages, but it's enough to be very annoying.

Even if we were able to fix everything, I'd still rather not wait for
us to find something else that is a problem.

Thanks for the discussion though. I appreciate the feedback.


-Nathan

On Mon, Sep 27, 2010 at 12:12 PM, Alan Runyan <runyaga at gmail.com> wrote:
>> We're currently deploying plone with zrs which replicates to read-only
>> databases which is what actually gets served to the user. It works
>> fine in most cases, but there seem to be odd issues here and there
>> where plone will try to write to the database and will throw an error
>> on the page load.
>
> We have read only Plone's in production and this works fine.
> Please enumerate the problems on a plone ticket, dev.plone.org
> (mention your py, zope, plone versions).
>
>> Is there anyway to get it to not error out and not simply silently not
>> write to the database?
>
> It would be much safer to fix Zope/Plone application than to monkey
> around with silently working around the readonly aspects of the
> database. especially since you are already putting the database
> into a readonly mode.
>
> again, we are doing this fine in production.  so it must be something
> in your application causing writes.
>
> cheers
> alan
>