Can you explain to me how you were able to "kill" the running process trying to reach a dead, down, unavailable proxy?

I've tried this, and once I attempt to access content via a down proxy in my array, I have to sit and wait until that proxy times out, before I can try again.

I'm not sure how to capture that "downed" state, kill the process attempting to use that proxy, and then loop across another proxy until I find one that works.