NGX_HTTP_CACHE_STALE  432 http/ngx_http_file_cache.c             rc = NGX_HTTP_CACHE_STALE;
NGX_HTTP_CACHE_STALE  702 http/ngx_http_upstream.c             rc = NGX_HTTP_CACHE_STALE;
NGX_HTTP_CACHE_STALE  723 http/ngx_http_upstream.c     case NGX_HTTP_CACHE_STALE:
NGX_HTTP_CACHE_STALE 1668 http/ngx_http_upstream.c                 u->cache_status = NGX_HTTP_CACHE_STALE;
NGX_HTTP_CACHE_STALE 2862 http/ngx_http_upstream.c                     u->cache_status = NGX_HTTP_CACHE_STALE;