Thierry Florac wrote at 2002-12-23 09:52 +0100:

I didn't found any answer to this probably simple question : what's the best way to define a "good" number of threads for Zope ? Is the default number defined in z2.py (4) the best for every situation, or does this number have to be increased when working with sites with a high volume of transactions ?? When you are concerned with throughput (and you do most work inside Zope and not in external processes, such as external relational databases), you use a small number of threads.

When most of the work is done outside of Zope or you want to optimize response time, a higher thread number is adequate. Each thread requires a ZODB database connection. The Zope code currently limits the number of such connections to 7. When you want to increase Zope's thread number beyond 7, you should also increase the connection number. Zope will then need more memory (for its ZODB caches). Dieter