[Zope] Zope Startup Question: Threads Directive

[Chris McDonough]

> Question.  In Zope startup, is the directiuve "-t 9" equivilent
to:
>
> "%1 %2 %3 %4 %5 %6 %7 %8 %9"

No... these are command-line options.  When you pass -t9, this takes
the place of one of them.

> On a fast W2K box, running Zope standalone, with a lot of RAM,
> what would the optimal number of threads be, for some moderately
> loaded websites?

The default (4) is generally OK.  Increasing the number of threads
may not increase performance unless you also bump up the size of the
ZODB database connection pool (which is hardcoded in the source to 7
via the "pool_size" parameter in the __init__ method of DB.py inside
lib/python/ZODB).  You can also mess around with the ZODB cache size
parameter in the Database Settings control panel applet to see how
it effects performance.

Coming up with optimum performance numbers is a black art and varies
widely from system to system.  I recommend sticking with the
defaults unless you're willing to spend time doing load testing
under different numbers of threads and different connection pool
sizes, ZODB cache sizes, and other performance-affecting settings.

In other words, "shrug". ;-)

- C