Failover Proxies?

[aw042]

Does anyone know a way to implement a failover feature for proxies instead of just shuffling everything in the proxyUrls list? Perhaps with session management?

I subscribe to a couple of different proxy providers. I have data center, residential, and mobile IPs. Their price increases in that order. Ideally, I would like to try to crawl using data center IPs, if that errors then it would fail over to residential IPs, and then the residential IPs would fail over to mobile IPs.

It would be even better if I could specify 3 rotations on the data center IP list before failing over to residential list, then another 3 residential list rotations before failing over to mobile with 3 rotations before moving onto the next url/domain.