2015/06/16 15:44:21 [error] 1650#0: *38787 connect() failed (111: Connection refused) while connecting to upstream, client: 178.17.6.166, server: test.com, request: "POST /wp-admin/admin-ajax.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:8000", host: "test.com", referrer: "http://test.com/wp-admin/"
Solution is hhvm.server.ip = 127.0.0.1
http://stackoverflow.com/questions/27137094/hhvm-nginx-connection-refused