Recently, when troubleshooting an online problem, I found that the nginx log $upstream_addr field actually returned 2 values, in the form of '192.168.1.1:80, api-servers', where api-servers refers to you The upstream is followed by the group name, and the part has only one value 'api-servers'. Under normal circumstances, this place should be like "192.168.1.1:80", that is, one request falls to one backend service.