Vielen Dank für eure Unterstützung. Ich hab nun die Erklärung in der Maillingliste von mod_perl bekommen und post sie hier nochmal abschließend, könnte bestimmt noch für den ein oder anderen interessant sein!

> Yes, as Foo observed, this will happen 2x on Unix, 4x on Windows due to the MPM.
>
> Notice that 1x and 2x (and 5x and 8x and 11x upon restarts) are all occurring
> in the parent. They aren't in the worker process at all, they were only pre-
> tested to ensure your script compiles and runs.
>
> The 3x and 4x times are in the child process that serves your request. First
> to pretest the config (yes, again!) and then the copy that will persist until
> the worker process terminates.
>
> Upon a graceful restart, that copy dies, the config is reprocessed in the parent
> 1x only again, and then 2x in the child.
>
> We could (obviously) dump the extra success-test in the child. But doing so
> would break a huge assumption by coders like yourselves that rely on the pre
> test followed by the actual run.
>
> On Unix, you will see it run 1x for config test, followed by the 2x for the
> worker children. On a graceful restart, you'll see it happen a 3x time, etc.
>
> Bill