[swift] Unable to get or create objects

Hello, I don't have a lot of knowledge about Openstack. I have installed Swift in my Openstack Ussuri cloud with one storage node but I am not be able to list or create objects. In the controller node I saw these errors: proxy-server: ERROR with Account server 10.20.20.1:6202/sdb re: Trying to HEAD /v1/AUTH_c2b7d6242f3140f09d283e8fbb88732a: Connection refused (txn: tx370fb5929a6c4cf397384-00603dfe35) proxy-server: Account HEAD returning 503 for [] (txn:tx370fb5929a6c4cf397384-00603dfe35) Any idea? Thanks in advance!