Quantil 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 and the real-time log. 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. Some variables are Nginx native taken from the open source version of Nginx, while the other variables are CDN Pro proprietary. Most variables here are read-only. The writable ones are indicated by R/W. The variables with numerical values are tagged with #.

To use the variables properly, it is important to understand the request processing lifecycle. When Nginx processes a request, it goes through several stages. As the stages progress, Nginx variables are populated or updated dynamically. Accessing variables prematurely can lead to unexpected outcomes. For instance, upstream-related variables $upstream_* should not be accessed before a request is even passed to the upstream. Similarly, variables like $bytes_sent, $body_bytes_sent and $sc_completed, which are available only after the response is fully completed, should not be accessed before completion of the response (not even by add_header which is executed when response header is being constructed). These variables should only be accessed at log phase by custom_log_field or in realtime logs. In addition, variables like $request_time are updated continuously throughout the request lifecycle. If the variables are accessed before they are finalized, the values obtained early will differ from the ones at the request's completion.

Note: Most variables were previously also available in Load Balancer Logic. However, following the upgrade of the edge node structure, Load Balancer Logic has been deprecated. The Load Balancer Logic should no longer be used.

Variable Name	Description	Nginx Native
$arg_name	query parameter with the specified name	Yes
$args	the full query string from client	Yes
$body_bytes_sent	# body bytes sent to client	Yes
$bytes_sent	# total response bytes to client	Yes
$cache_misc	a R/W writable variable to add parameters to the cache key	No
$cdn_cache_status	cache status: HIT, MISS, BYPASS, EXPIRED, STALE, UPDATING, REVALIDATED.	No
$client_country_code	client’s ISO 3166 country code	No
$client_http_version	client's HTTP version, like "HTTP/1.1"	No
$client_ip_version	# client's IP version: 4 for IPv4; 6 for IPv6	No
$client_isp	client's ISP information	No
$client_province_code	client's China province code	No
$client_real_ip	client's IP address	No
$connection_requests	# current number of requests in the connection	Yes
$content_code	a R/W writable variable to assign a code to content for reporting and billing purposes	No
$content_length	# request's Content-Length header	Yes
$content_type	request's Content-Type header	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
$cpu_time_ns	# CPU time in nanoseconds（1e-9s) spent on processing the request, before transferring the response body.	No
$dollar_sign	a literal dollar sign	No
$download_time	# the time in seconds 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 the sum of $request_end_time/$turn_around_time/$transfer_time. Another variable, $download_time_ms, shares the same meaning but is measured in milliseconds. The meaning of $download_time is the same as another variable, $request_time.	No
$error_code	error about client and origin	No
$extra_deliver_time_ms	# the estimated time in milliseconds needed to flush the TCP send buffer.	No
$host	host header, same as $http_host	Yes
$hostname	server's hostname	Yes
$http_name	request header with the specified name	Yes
$http_host	request's Host header	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	No
$invalid_referer	empty string if the “Referer” request header field value is considered valid; otherwise “1”	Yes
$is_args	empty or "?", when query string exists	Yes
$msec	# current Unix time in seconds with milliseconds resolution	Yes
$origin_host	origin's hostname	No
$origin_ip	IP and port of the origin. The format is IP:port	No
$origin_status_code	origin's status code	No
$pid	process ID of the service	Yes
$pipe	"p" if request is pipelined, or "." otherwise.	Yes
$property_ver	# the property version number	No
$qtl_cpu_cycle	Deprecated. Please use $cpu_time_ns instead.	No
$qtl_req_id	Deprecated. Please use $unique_req_id instead.	No
$qtl_upstream_cache_status	Deprecated. Please use $cdn_cache_status instead.	No
$random_N	# A random integer uniformly distributed in [0, N-1]. N can be an integer in [2, 1e9].	No
$realtime_log_ds_factor	# RT log downsample factor. A value N means one log entry for every N requests. Users can use the directive realtime_log_downsample to override the default sample rate.	No
$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
$remote_user	user name extracted from the Authorization header if Basic authentication is used.	Yes
$request	full HTTP request line	Yes
$request_cpu_time	# CPU time in nanoseconds（1e-9s) spent on processing the request, before transferring the response body. Another variable $cpu_time_ns shares the same meaning.	No
$request_end_time	# the time in seconds it takes to receive the request header from the client and be ready to process or forward it. Another variable request_end_time_ms shares the same meaning but in milliseconds.	No
$request_length	# length of request line, header and body	Yes
$request_method	HTTP method: GET, POST, etc.	Yes
$request_scheme	"http" or "https"	No
$request_ssl_handshake_time	# CPU time, in nanoseconds, spent on TLS handshake	No
$request_start_time	# the Unix time (in seconds with milliseconds resolution) when the first byte of the request is received from the client.	No
$request_time	# request processing time in seconds with a milliseconds resolution; time elapsed since the first bytes were read from the client. The value is equal to the sum of the values of 3 variables: $request_end_time, $turn_around_time and $transfer_time. When the request and response sizes are small, $request_end_time and $transfer_time may be 0 and $request_time may have the same value as $turn_around_time.	Yes
$request_uri	request URI from the client, beginning with '/' and including the query string	Yes
$sc_completed	# Value is 1 if the last byte was served to the client; 0 otherwise.	No
$sc_initial	# Value is 1 if the first byte was served to the client; 0 otherwise.	No
$sec	# current Unix time in integer seconds	No
$sent_http_name	header with the specified name sent to client	Yes
$sent_http_content_length	# Content-Length to client	Yes
$sent_http_content_type	Content-Type to client	Yes
$served_from_cache	# Value is 1 for a HIT on edge; 0 for a MISS.	No
$server_addr	IP address of the edge server	Yes
$server_level	# Level of the cache server. 1 means edge, and 2 means intermediate.	No
$server_name	The value specified in the property's hostnames that matched the incoming request.	Yes
$server_region	Country code of the edge server, e.g. CN, US	No
$server_province_code	The edge server's China province code	No
$server_protocol	HTTP/1.1, HTTP/2.0 or HTTP/3.0	Yes
$service_port	# port number that received the request	No
$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	No
$ssl_cipher	TLS cipher suite used	Yes
$ssl_client_escaped_cert	client certificate in PEM format (urlencoded)	Yes
$ssl_client_fingerprint	SHA1 fingerprint of the client certificate	Yes
$ssl_client_i_dn	"issuer DN" string of the client certificate	Yes
$ssl_client_raw_cert	client certificate in PEM format	Yes
$ssl_client_s_dn	"subject DN" string of the client certificate	Yes
$ssl_client_serial	serial number of the client certificate	Yes
$ssl_client_v_end	end date of the client certificate	Yes
$ssl_client_v_remain	# the number of days until the client certificate expires	Yes
$ssl_client_v_start	start date of the client certificate	Yes
$ssl_client_verify	result of client certificate verification	Yes
$ssl_protocol	returns protocol name like "TLSv1.1"	Yes
$ssl_server_name	TLS SNI servername	Yes
$status	HTTP status code to client	Yes
$tcpinfo_delivery_rate	# the rate, in bytes/s, at which the sent data is acknowledged by the client.	No
$tcpinfo_min_rtt	# minimum RTT, in microseconds, observed by TCP stack for the connection	No
$tcpinfo_rtt	# latest RTT, in microseconds, observed by TCP stack for the connection	Yes
$time_http	current time in RFC 7231 format that can be used for HTTP Date header	No
$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
$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
$unique_req_id	a unique ID for the request	No
$upstream_bytes_received	# number of bytes received from a parent or origin server	Yes
$upstream_bytes_sent	# number of bytes sent to a parent or origin server	Yes
$upstream_connect_time	# time spent in seconds with millisecond resolution establishing a connection with a parent or origin server	Yes
$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
$upstream_header_time	# time spent in seconds with millisecond resolution receiving the response header from a parent or origin server	Yes
$upstream_http_name	header with the specified name received from the upstream server. May be served from the cache.	Yes
$upstream_response_status	status code from a parent or origin server. Value will be 0 for a cache HIT.	No
$upstream_response_time	# time spent in seconds with millisecond resolution receiving the complete response from a parent or origin server	Yes
$upstream_server_type	'O' for origin server; 'C' for parent cache server.	No
$upstream_trailer_name	trailer with the specified name passed from the Edge Logic with the add_trailer directive. This variable is deprecated.	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