NGX_STREAM_UPSTREAM_BACKUP   91 src/stream/ngx_stream_upstream.c                                            |NGX_STREAM_UPSTREAM_BACKUP);
NGX_STREAM_UPSTREAM_BACKUP  242 src/stream/ngx_stream_upstream.c             if (!(uscf->flags & NGX_STREAM_UPSTREAM_BACKUP)) {
NGX_STREAM_UPSTREAM_BACKUP  302 src/stream/ngx_stream_upstream_least_conn_module.c                   |NGX_STREAM_UPSTREAM_BACKUP;