Onionbalance is the best way to load balance onion services across multiple backend Tor instances. This way the load of introduction and rendezvous requests get distributed across multiple hosts. Onionbalance provides load-balancing while also making onion services more resilient and reliable by eliminating single points-of-failure.
Latest release: 0.2.2 (Change Log)
GitHub mirror: https://github.com/torproject/onionbalance
IRC: #tor-dev @ OFTC
Onionbalance supports both v2 and v3 onions but because of the different setup procedure, we have separate guides for them.