[Zope-dev] Cache growing during single REQUEST

[Toby Dickenson]

On Wednesday 03 September 2003 12:15, Chris Withers wrote:

> If the object load would cause the cache to go above it's maximum number,

*Number* isnt the the right parameter to control here..... We need to limit 
the total amount of RAM. Objects are of variable size, and the largest ZODB 
objects are very much bigger than the average.

One task I would like to find time for is making the cache aware of this. For 
example, this would fix the problem where the current cache unfairly 
penalises ZCatalog operations because its BTree nodes are so small.

> then boot an object out of the cache in order to make room for the new one.

That would have a bad effect on ReadConflictErrors. Cache purging should only 
happen on transaction boundaries for storages where ReadConflictErrors are 
possible.

> control the amount of memory Zope
> actually uses and other requests would stand a chance of beind processed
> normally.

I havent seen a mention of ulimit or autolance earlier in this thread.... They 
are mostly adequate protection against the work problems.


-- 
Toby Dickenson