# 前台服务后端地址，多个地址可用与负载均衡
# 解析以逗号分隔的多个 upstream 值

    upstream web_servers {
        server $UPSTREAM_WEB_SERVERS;
    }

    upstream manage_servers {
        server $UPSTREAM_MANAGE_SERVERS;
    }

    upstream rasa_servers {
        server $UPSTREAM_RASA_SERVERS;
    }

	upstream graph_servers {
        server $UPSTREAM_GRAPH_SERVERS;
    }