+{% include 'notebox_begin' %}
+If you are upgrading a cluster where Nginx is configured to proxy @ws@ requests to puma, change the @server_name@ value in the old configuration block so it doesn't conflict. When the new configuration is working, delete the old Nginx configuration sections (i.e., the "upstream websockets" block, and the "server" block that references @http://websockets@), and disable/remove the runit or systemd files for the puma server.
+{% include 'notebox_end' %}