Fixed background requests with asynchronous operations. If the main request was finalized while a background request performed an asynchronous operation, the main request ended up in ngx_http_writer() and was not finalized until a network event or a timeout. For example, cache background update with aio enabled made nginx unable to process further client requests or close the connection, keeping it open until client closes it. Now regular finalization of the main request is not suspended because of an asynchronous operation in another request. If a background request was terminated while an asynchronous operation was in progress, background request's write event handler was changed to ngx_http_request_finalizer() and never called again. Now, whenever a request is terminated while an asynchronous operation is in progress, connection error flag is set to make further finalizations of any request with this connection lead to termination. These issues appeared in 1aeaae6e9446 (not yet released).

fastcgi_param  QUERY_STRING       $query_string;
fastcgi_param  REQUEST_METHOD     $request_method;
fastcgi_param  CONTENT_TYPE       $content_type;
fastcgi_param  CONTENT_LENGTH     $content_length;

fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
fastcgi_param  REQUEST_URI        $request_uri;
fastcgi_param  DOCUMENT_URI       $document_uri;
fastcgi_param  DOCUMENT_ROOT      $document_root;
fastcgi_param  SERVER_PROTOCOL    $server_protocol;
fastcgi_param  REQUEST_SCHEME     $scheme;
fastcgi_param  HTTPS              $https if_not_empty;

fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
fastcgi_param  SERVER_SOFTWARE    nginx/$nginx_version;

fastcgi_param  REMOTE_ADDR        $remote_addr;
fastcgi_param  REMOTE_PORT        $remote_port;
fastcgi_param  SERVER_ADDR        $server_addr;
fastcgi_param  SERVER_PORT        $server_port;
fastcgi_param  SERVER_NAME        $server_name;

# PHP only, required if PHP was built with --enable-force-cgi-redirect
fastcgi_param  REDIRECT_STATUS    200;