To be brief - yes this is what you would expect to happen. Because the open creates the filehandle and it isn't closed and because mod_perl is keeping the code loaded it doesn't disappear - so the children (i.e. the processes needed to provide the data) aren't reaped and so become zombies.

So the answer in this case is not to be lazy (or sloppy) and do an explicit close.

The number of zombies doesn't grow for ever - what you seem to get is (number of httpd processes X number of open calls). In my case this was 9 calls X 4 processes hence my concern at sudenly seing 36 zombies appear.
Subsequent reuse of each process seems to kill off the existing zombies belonging to the process and then create a replacement set.

If you read the (massive) mod_perl guide it does tell you to do this - but in my haste I didn't spot it.

Thanks for all the (analysis|help|advice)

Odud