CDNetworks Documentation

Built-in Variables

The table below lists all the built-in variables supported by the CDN Pro servers. You can use them in Edge Logic or Load Balancer Logic. Not all variables are supported in both places. The real-time log supports the same set of variables as the Load Balancer Logic. The variables with numerical values are tagged with #. If you use the CDN Pro portal to edit the property, typing $ at a position where a variable is allowed will list all the supported variables.

Variable Name	Description	Edge Logic	LB Logic
$arg_name	query parameter with the specified name	Yes	Yes
$args	the full query string from client	Yes	Yes
$body_bytes_sent	# body bytes sent to client	No	Yes
$bytes_sent	# total response bytes to client	No	Yes
$cache_misc	parameters to add to the cache key	Yes	No
$client_country_code	client’s ISO 3166 country code	Yes	Yes
$client_http_version	client's HTTP version, like "HTTP/1.1"	Yes	Yes
$client_ip_version	# client's IP version: 4 for IPv4; 6 for IPv6	Yes	Yes
$client_isp	client's ISP information	Yes	Yes
$client_province_code	client's China province code	Yes	Yes
$client_real_ip	client's IP address	Yes	Yes
$connection_requests	# current number of requests in the connection	No	Yes
$content_length	# request's Content-Length header	Yes	Yes
$content_type	request's Content-Type header	Yes	Yes
$cookie_name	cookie with the specified name received from the client. The dot character (.) is allowed in this variable name to support cookie names that contain dots. You may need to use curly braces to separate this variable from a trailing literal dot. For example: $cookie_abc.test or ${cookie_abc.test} both refer to the value of the cookie "abc.test", but ${cookie_abc}.test gives you the value of the cookie "abc" followed by the literal ".test".	Yes	Yes
$dollar_sign	a literal dollar sign	Yes	Yes
$download_time	# the time from when CDN Pro receives the client request until CDN Pro sends the response body to the system buffer, the value should be equal to sum of $request_end_time/$turn_around_time/$transfer_time, in seconds. Another variable download_time_ms shares the same meaning but in milliseconds.	No	Yes
$error_code	error about client and origin	No	Yes
$extra_deliver_time_ms	# the estimated time in milliseconds needed to flush the TCP send buffer.	No	Yes
$host	host header, same as $http_host	Yes	Yes
$hostname	server's hostname	Yes	Yes
$http_name	request header with the specified name	Yes	Yes
$http_host	request's Host header	Yes	Yes
$ignored_body_in_cache_key	empty string when proxy_request_body_in_cache_key is off, '0' when the request body hash is included in the cache, or '1' otherwise	Yes	No
$invalid_referer	empty string if the “Referer” request header field value is considered valid; otherwise “1”	Yes	Yes
$is_args	empty or "?", when query string exists	Yes	Yes
$msec	# current time in seconds with milliseconds resolution	Yes	Yes
$sec	# current unix time in integer seconds	Yes	Yes
$origin_host	origin's hostname	Yes	Yes
$origin_ip	origin's IP	Yes	Yes
$origin_status_code	origin's status code	Yes	Yes
$pid	process ID of the service	Yes	Yes
$pipe	"p" if request is pipelined, or "." otherwise.	No	Yes
$property_ver	# the property version number	Yes	Yes
$qtl_cpu_cycle	# CPU time in nanoseconds（1e-9s) spent in LB7, and in ES before transferring the response body	No	Yes
$qtl_req_id	a unique ID for the request	Yes	Yes
$qtl_upstream_cache_status	cache status: HIT, MISS, BYPASS, EXPIRED, STALE, UPDATING, REVALIDATED.	Yes	Yes
$random_N	# A random integer in [0, N-1]. N can be an integer in [2,1e9].	Yes	Yes
$realtime_log_ds_factor	# RT log downsample factor. A value N means one log entry for every N requests	No	Yes
$realtime_log_ds_ratio	# RT log downsample ratio, the reciprocal of $realtime_log_ds_factor. The value should be a decimal number between 0 and 1.	No	Yes
$remote_user	user name extracted from the Authorization header if Basic authentication is used.	Yes	Yes
$request	full HTTP request line	Yes	Yes
$request_cpu_time	# CPU time, in nanoseconds, spent on processing the request by the ES stage (when used in the Edge Logic), or by the LB stage (when used in the real-time log)	Yes	Yes
$request_end_time	# the time needed for CDN Pro to receive 'fully' the request from the Client and be ready to process/forward it, in seconds. Another variable request_end_time_ms shares the same meaning but in milliseconds.	No	Yes
$request_length	# length of request line, header and body	Yes	Yes
$request_method	HTTP method: GET, POST, etc.	Yes	Yes
$request_scheme	"http" or "https"	Yes	Yes
$request_time	# request processing time in seconds with milliseconds resolution; time elapsed since the first byte was read from the client	Yes	Yes
$request_uri	request URI from the client, beginning with '/' and including the query string	Yes	Yes
$sc_completed	# Value is 1 if the last byte was served to the client; 0 otherwise.	No	Yes
$sc_initial	# Value is 1 if the first byte was served to the client; 0 otherwise.	No	Yes
$sent_http_name	header with the specified name sent to client	No	Yes
$sent_http_content_length	# Content-Length to client	No	Yes
$served_from_cache	# Value is 1 for a HIT on edge; 0 for a MISS.	Yes	Yes
$server_addr	IP address of the edge server	No	Yes
$server_level	# Level of the cache server. 1 means edge, and 2 means intermediate.	No	Yes
$server_name	The value specified in the property's hostnames that matched the incoming request.	Yes	Yes
$server_region	Country code of the edge server, E.g. CN, US	Yes	Yes
$server_protocol	HTTP/1.1 or HTTP/2.0	No	Yes
$service_port	# port number that received the request	Yes	Yes
$sorted_querystring_args	variable providing an ASCII-based sorted list of input query parameters; it can be modified by the "sorted_querystring_filter_parameter" directive	Yes	Yes
$ssl_cipher	TLS cipher suite used	No	Yes
$request_ssl_handshake_time	# CPU time, in nanoseconds, spent on TLS handshake	No	Yes
$ssl_protocol	returns protocol name like "TLSv1.1"	No	Yes
$ssl_server_name	TLS SNI servername	No	Yes
$status	HTTP status code to client	Yes	Yes
$tcpinfo_delivery_rate	# the rate, in bytes/s, at which the sent data is acknowledged by the client.	No	Yes
$tcpinfo_min_rtt	# minimum RTT, in microseconds, observed by TCP stack for the connection	No	Yes
$tcpinfo_rtt	# latest RTT, in microseconds, observed by TCP stack for the connection	No	Yes
$time_http	current time in RFC 7231 format that can be used for HTTP Date header	Yes	Yes
$transfer_time	# the time needed for CDN Pro to send the full requested object ( up to last byte ) to system buffer, in seconds. Another variable transfer_time_ms shares the same meaning but in milliseconds.	No	Yes
$turn_around_time	# the time needed for CDN Pro to receive first byte of response of origin, in seconds. Another variable turn_around_time_ms shares the same meaning but in milliseconds.	No	Yes
$upstream_bytes_received	# number of bytes received from a parent or origin server	Yes	No
$upstream_bytes_sent	# number of bytes sent to a parent or origin server	Yes	No
$upstream_connect_time	# time spent in seconds with millisecond resolution establishing a connection with a parent or origin server	Yes	No
$upstream_cookie_name	cookie with the specified name received from the upstream server in the “Set-Cookie” response header field. May be served from the cache. The dot character (.) is allowed in this variable name to support cookie names that contain dots. You may need to use curly braces to separate this variable from a trailing literal dot. For example: $upstream_cookie_abc.test or ${upstream_cookie_abc.test} both refer to the value of the cookie "abc.test", but ${upstream_cookie_abc}.test gives you the value of the cookie "abc" followed by the literal ".test".	Yes	Yes
$upstream_header_time	# time spent in seconds with millisecond resolution receiving the response header from a parent or origin server	Yes	No
$upstream_http_name	header with the specified name received from the upstream server. May be served from the cache.	Yes	Yes
$upstream_response_status	status code from a parent or origin server. Value will be 0 for a cache HIT.	Yes	No
$upstream_response_time	# time spent in seconds with millisecond resolution receiving the complete response from a parent or origin server	Yes	No
$upstream_server_type	'O' for origin server; 'C' for parent cache server.	Yes	No
$upstream_trailer_name	trailer with the specified name passed from the Edge Logic with the add_trailer directive.	No	Yes
$uri	normalized request URI beginning with '/' and excluding the query string. The value may be modified by the "rewrite" directive in the Edge Logic.	Yes	Yes