threads : The problem with this is managing the threads. Is there an efficient thread Manager or thread pool library that can help me with this?

Personally I have not found "managing the threads" to be problematic. Since I don't know quite why you perceive there to be a problem there's not much I can suggest to solve it. What precisely is the problem as you see it?

I am also not sure if I can share the readOnly object easily.

use threads::shared;
my $readOnlySchema :shared = foo();
[download]

That seems pretty easy to me.