[Zope] high loads, more threads, spinning wheels

[Jim Abramson]

Can this be taken to mean that:

- the practical maximum number of threads to run your single (non-ZEO)
zope instance is {number of zodb connections in pool} else you risk
deadlock

if yes, would upping the number of ZODB connections effectively raise
the ceiling - e.g. 12 ZODB connections -> 12 threads should perform
properly ?   Is increasing the number of ZODB cx's possible, let alone
advisable?  (why the default of 7 - not 6 or 8?) 

More concretely, is there any good way to increase the request-handling
capacity of a standalone instance, beyond the limits imposed by the
defaults, without deploying ZEO?
 
> 
> To put it in a very simple way, you should not tweak the 
> threads setting unless you really know what you are doing. If 
> your goal is performance the usual way of going about that is 
> to run ZEO and add ZEO clients as needed.
> 
> You're bumping into the very simple fact that there are two 
> items interacting badly: Threads and the connections in the 
> Zope database connection pool. A thread, under normal 
> circumstances, can only do work if it has a connection to 
> work with, and wwill only release the connection when the 
> request is finished. There are 7 connections in the pool by default.
> 
> jens
>