[Zope-dev] Zope RAM usage, _v_ variables and the ZODB cache

[Chris Withers]

Toby Dickenson wrote:

>>Which, unfortunately, then leaves us with the problem of how to stop Zope
>>using up an undeterminable amount of memory...
> 
> No, we just exclude objects with _v_ attribute from mid-transaction 
> deactivation. There arent many objects in that category, but they do need 
> protection.

Indeed, I guess they're unlikely to be the ones that cause Zope's memory usage 
to baloon...

> But, your proposal means we would improve the situation for transactions that 
> read from an undeterminable number of persistent objects. 

Yep.

> It does not help 
> for transactions that touch an undeterminable number of non-persistent 
> objects,

Under what circumstances is this likely to happen?

> or transactions that change an undeterminable number of persistent 
> objects. Is the gain big enough to justify the effort?

Well, hmmm, that's tricky. I guess that's the point where the fact that Zope so 
neatly hides the fact that it's interacting with a concurrent transactional 
database becomes a PITA.

I've written code in the past that just does a get_transaction().commit() half 
way through a request. I don't remember any problems, but how hot exactly is the 
fire I'm playing with?

cheers,

Chris