I've been pulling my hair out trying to set up two pushpin instances communication with my backend using zeromq. Everything is working fine with one instance, following the "example without a webserver" from pushpins github page. The problem seems to be how pushpin is handling the req socket. Setting sock.connect('tcp://127.0.0.1:10000') works but sock.bind('tcp://*:10000') (using bind with a wildcard) just hangs and end up after a while with http://localhost:7999/
-> zhttpreq/tcp://127.0.0.1:10000 code=502 in the pushpin-proxy log.