[CDBI] Class-DBI on mod_perl2 (Apache2 threaded)

Perrin Harkins perrin at elem.com
Fri Nov 11 13:41:18 GMT 2005

On Thu, 2005-11-10 at 22:50 -0800, Ryan Tate wrote:
> I may well be misunderstanding, but I thought mod_perl2 threaded
> (worker MPM) maintained a pool of perl interpreters that are shared
> among threads, and that the number of perl interpreters can be
> significantly less than the number of threads.

That's correct, but it doesn't help with this.

With a pre-fork MPM, you run a reverse proxy in front of your mod_perl
server to handle the static content.  With a threaded MPM, you can set
the number of interpreters lower than the number of apache threads, and
let the non-perl threads handle the static content.  Either way though,
you still need 5 interpreters to service 5 simultaneous requests for
dynamic content, and those 5 will take more memory with threads than
with processes.

In addition, perl built with threads is about 15% slower than perl built
without threads.  This affects you even if you never actually use the
threading.  That's why I build my own perl instead of using the one
packaged by Red Hat.

- Perrin

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