You can avoid getting a zombie, and copy-on-write means that most of the memory is shared. This is all described in the mod_perl guide here. Now, if these things you do in the cleanup phase are very short, this is overkill, but for long-running jobs it's really the best option. Another good approach is to use a queue, so that you can just dump jobs onto it and move on, and a separate process monitors the queue and picks up jobs that apache adds to it.