Nginx virtual host traffic status module

Version
Dependencies
Screenshots
Installation
Synopsis
Description
Control
To get status of traffic zones on the fly
- To get fully zones
- To get group zones
- To get each zones
To reset traffic zones on the fly
- To reset fully zones
- To reset group zones
- To reset each zones
To delete traffic zones on the fly
- To delete fully zones
- To delete group zones
- To delete each zones
JSON
Json used by status
Json used by control
Variables
Limit
To limit traffic for server
To limit traffic for filter
To limit traffic for upstream
Use cases
To calculate traffic for individual country using GeoIP
To calculate traffic for individual storage volume
To calculate traffic for individual user agent
Customizing
To customize after the module installed
To customize before the module installed
Directives
vhost_traffic_status
vhost_traffic_status_zone
vhost_traffic_status_display
vhost_traffic_status_display_format
vhost_traffic_status_display_jsonp
vhost_traffic_status_filter
vhost_traffic_status_filter_by_host
vhost_traffic_status_filter_by_set_key
vhost_traffic_status_filter_check_duplicate
vhost_traffic_status_limit
vhost_traffic_status_limit_traffic
vhost_traffic_status_limit_traffic_by_set_key
vhost_traffic_status_limit_check_duplicate
TODO
Donation
Author

Version

This document describes nginx-module-vts v0.1.10 released on 17 Jul 2016.

Dependencies

nginx

Compatibility

1.11.x (last tested: 1.11.8)
1.10.x (last tested: 1.10.1)
1.9.x (last tested: 1.9.9)
1.8.x (last tested: 1.8.0)
1.6.x (last tested: 1.6.3)
1.4.x (last tested: 1.4.7)

Earlier versions is not tested.

Screenshots

Installation

Clone the git repository.

shell> git clone git://github.com/vozlt/nginx-module-vts.git

Add the module to the build configuration by adding --add-module=/path/to/nginx-module-vts
Build the nginx binary.
Install the nginx binary.

Synopsis

http {
    vhost_traffic_status_zone;

    ...

    server {

        ...

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }
}

Description

This is an Nginx module that provides access to virtual host status information. It contains the current status such as servers, upstreams, caches. This is similar to the live activity monitoring of nginx plus. The built-in html is also taken from the demo page of old version.

First of all, the directive vhost_traffic_status_zone is required, and then if the directive vhost_traffic_status_display is set, can be access to as follows:

/status/format/json
/status/format/html
/status/format/jsonp
/status/control
If you request /status/format/json, will respond with a JSON document containing the current activity data for using in live dashboards and third-party monitoring tools.
If you request /status/format/html, will respond with the built-in live dashboard in HTML that requests internally to /status/format/json.
If you request /status/format/jsonp, will respond with a JSONP callback function containing the current activity data for using in live dashboards and third-party monitoring tools.
If you request /status/control, will respond with a JSON document after it reset or delete zones through a query string. See the Control.

JSON document contains as follows:

{
    "nginxVersion": ...,
    "loadMsec": ...,
    "nowMsec": ...,
    "connections": {
        "active":...,
        "reading":...,
        "writing":...,
        "waiting":...,
        "accepted":...,
        "handled":...,
        "requests":...
    },
    "serverZones": {
        "...":{
            "requestCounter":...,
            "inBytes":...,
            "outBytes":...,
            "responses":{
                "1xx":...,
                "2xx":...,
                "3xx":...,
                "4xx":...,
                "5xx":...,
                "miss":...,
                "bypass":...,
                "expired":...,
                "stale":...,
                "updating":...,
                "revalidated":...,
                "hit":...,
                "scarce":...
            },
            "requestMsec":...
        }
        ...
    },
    "filterZones": {
        "...":{
            "...":{
                "requestCounter":...,
                "inBytes":...,
                "outBytes":...,
                "responses":{
                    "1xx":...,
                    "2xx":...,
                    "3xx":...,
                    "4xx":...,
                    "5xx":...,
                    "miss":...,
                    "bypass":...,
                    "expired":...,
                    "stale":...,
                    "updating":...,
                    "revalidated":...,
                    "hit":...,
                    "scarce":...
                },
                "requestMsec":...
            },
            ...
        },
        ...
    },
    "upstreamZones": {
        "...":[
            {
                "server":...,
                "requestCounter":...,
                "inBytes":...,
                "outBytes":...,
                "responses":{
                    "1xx":...,
                    "2xx":...,
                    "3xx":...,
                    "4xx":...,
                    "5xx":...
                },
                "responseMsec":...,
                "weight":...,
                "maxFails":...,
                "failTimeout":...,
                "backup":...,
                "down":...
            }
            ...
        ],
        ...
    }
    "cacheZones": {
        "...":{
            "maxSize":...,
            "usedSize":...,
            "inBytes":...,
            "outBytes":...,
            "responses":{
                "miss":...,
                "bypass":...,
                "expired":...,
                "stale":...,
                "updating":...,
                "revalidated":...,
                "hit":...,
                "scarce":...
            }
        },
        ...
    }
}

main
Basic version, uptime((nowMsec - loadMsec)/1000)
nowMsec, loadMsec is a millisecond.
connections
Total connections and requests(same as stub_status_module in NGINX)
serverZones
Traffic(in/out) and request and response counts and cache hit ratio per each server zone
Total traffic(In/Out) and request and response counts(It zone name is *) and hit ratio
filterZones
Traffic(in/out) and request and response counts and cache hit ratio per each server zone filtered through the vhost_traffic_status_filter_by_set_key directive
Total traffic(In/Out) and request and response counts(It zone name is *) and hit ratio filtered through the vhost_traffic_status_filter_by_set_key directive
upstreamZones
Traffic(in/out) and request and response counts per server in each upstream group
Current settings(weight, maxfails, failtimeout...) in nginx.conf
cacheZones
Traffic(in/out) and size(capacity/used) and hit ratio per each cache zone when using the proxy_cache directive.

The directive vhost_traffic_status_display_format sets the default ouput format that is one of json or html. (Default: json)

Traffic calculation as follows:

ServerZones
in += requested_bytes
out += sent_bytes
FilterZones
in += requested_bytes via the filter
out += sent_bytes via the filter
UpstreamZones
in += requested_bytes via the ServerZones
out += sent_bytes via the ServerZones
cacheZones
in += requested_bytes via the ServerZones
out += sent_bytes via the ServerZones

All calculations are working in log processing phase of Nginx. Internal redirects(X-Accel-Redirect or error_page) does not calculate in the UpstreamZones.

Caveats: this module relies on nginx logging system(NGX_HTTP_LOG_PHASE:last phase of the nginx http), so the traffic may be in certain cirumstances different that real bandwidth traffic. Websocket, canceled downloads may be cause of inaccuracies. The working of the module doesn't matter at all whether the access_log directive "on" or "off". Again, this module works well on "access_log off". When using several domains it sets to be first domain(left) of server_name directive. If you don't want it, see the vhost_traffic_status_filter_by_host, vhost_traffic_status_filter_by_set_key directive.

Control

It is able to reset or delete traffic zones through a query string. The request responds with a JSON document.

URI Syntax
/{status_uri}/control?cmd={command}&group={group}&zone={name}

http {

    geoip_country                   /usr/share/GeoIP/GeoIP.dat;

    vhost_traffic_status_zone;
    vhost_traffic_status_filter_by_set_key $geoip_country_code country::*;

    ...

    server {

        server_name example.org;

        ...

        vhost_traffic_status_filter_by_set_key $geoip_country_code country::$server_name;

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }                                                                                                                                                                                           }

If it set as above, then the control uri is like example.org/status/control.

The available request arguments are as follows:

cmd=<status|reset|delete>
status
- It returns status of traffic zones to json format like status/format/json.
reset
- It reset traffic zones without deleting nodes in shared memory.(= init to 0)
delete
- It delete traffic zones in shared memory. when re-request recreated.
group=<server|filter|upstream@alone|upstream@group|cache|*>
server
filter
upstream@alone
upstream@group
cache
zone=name
server
- name
filter
- filter_group@name
upstream@group
- upstream_group@name
upstream@alone
- @name
cache
- name

To get status of traffic zones on the fly

This is similar to the status/format/json except that it can get each zones.

To get fully zones

It is exactly the same with the status/format/json.
/status/control?cmd=status&group=*

To get group zones

serverZones
/status/control?cmd=status&group=server&zone=*
filterZones
/status/control?cmd=status&group=filter&zone=*
upstreamZones
/status/control?cmd=status&group=upstream@group&zone=*
upstreamZones::nogroups
/status/control?cmd=status&group=upstream@alone&zone=*
cacheZones
/status/control?cmd=status&group=cache&zone=*

To get each zones

single zone in serverZones
/status/control?cmd=status&group=server&zone=name
single zone in filterZones
/status/control?cmd=status&group=filter&zone=filter_group@name
single zone in upstreamZones
/status/control?cmd=status&group=upstream@group&zone=upstream_group@name
single zone in upstreamZones::nogroups
/status/control?cmd=status&group=upstream@alone&zone=name
single zone in cacheZones
/status/control?cmd=status&group=cache&zone=name

To reset traffic zones on the fly

It reset the values of specified zones to 0.

To reset fully zones

/status/control?cmd=reset&group=*

To reset group zones

serverZones
/status/control?cmd=reset&group=server&zone=*
filterZones
/status/control?cmd=reset&group=filter&zone=*
upstreamZones
/status/control?cmd=reset&group=upstream@group&zone=*
upstreamZones::nogroups
/status/control?cmd=reset&group=upstream@alone&zone=*
cacheZones
/status/control?cmd=reset&group=cache&zone=*

To reset each zones

single zone in serverZones
/status/control?cmd=reset&group=server&zone=name
single zone in filterZones
/status/control?cmd=reset&group=filter&zone=filter_group@name
single zone in upstreamZones
/status/control?cmd=reset&group=upstream@group&zone=upstream_group@name
single zone in upstreamZones::nogroups
/status/control?cmd=reset&group=upstream@alone&zone=name
single zone in cacheZones
/status/control?cmd=reset&group=cache&zone=name

To delete traffic zones on the fly

It delete the specified zones in shared memory.

To delete fully zones

/status/control?cmd=delete&group=*

To delete group zones

serverZones
/status/control?cmd=delete&group=server&zone=*
filterZones
/status/control?cmd=delete&group=filter&zone=*
upstreamZones
/status/control?cmd=delete&group=upstream@group&zone=*
upstreamZones::nogroups
/status/control?cmd=delete&group=upstream@alone&zone=*
cacheZones
/status/control?cmd=delete&group=cache&zone=*

To delete each zones

single zone in serverZones
/status/control?cmd=delete&group=server&zone=name
single zone in filterZones
/status/control?cmd=delete&group=filter&zone=filter_group@name
single zone in upstreamZones
/status/control?cmd=delete&group=upstream@group&zone=upstream_group@name
single zone in upstreamZones::nogroups
/status/control?cmd=delete&group=upstream@alone&zone=name
single zone in cacheZones
/status/control?cmd=delete&group=cache&zone=name

JSON

The following status information is provided in the JSON format:

Json used by status

/{status_uri}/format/json

/{status_uri}/control?cmd=status&...

nginxVersion
Version of the provided.
loadMsec
Loaded process time in milliseconds.
nowMsec
Current time in milliseconds
connections
active
- The current number of active client connections.
reading
- The total number of reading client connections.
writing
- The total number of writing client connections.
waiting
- The total number of wating client connections.
accepted
- The total number of accepted client connections.
handled
- The total number of handled client connections.
requests
- The total number of requested client connections.
serverZones
requestCounter
- The total number of client requests received from clients.
inBytes
- The total number of bytes received from clients.
outBytes
- The total number of bytes sent to clients.
responses
- 1xx, 2xx, 3xx, 4xx, 5xx
  - The number of responses with status codes 1xx, 2xx, 3xx, 4xx, and 5xx.
- miss
  - The number of cache miss.
- bypass
  - The number of cache bypass.
- expired
  - The number of cache expired.
- stale
  - The number of cache stale.
- updating
  - The number of cache updating.
- revalidated
  - The number of cache revalidated.
- hit
  - The number of cache hit.
- scarce
  - The number of cache scare.
requestMsec
- The average of request processing time.
filterZones
It provides the same fields with serverZones except that it included group names.
upstreamZones
server
- An address of the server.
requestCounter
- The total number of client connections forwarded to this server.
inBytes
- The total number of bytes received from this server.
outBytes
- The total number of bytes sent to this server.
responses
- 1xx, 2xx, 3xx, 4xx, 5xx
  - The number of responses with status codes 1xx, 2xx, 3xx, 4xx, and 5xx.
responseMsec
- The average time to receive the last byte of data.
weight
- Current weight setting of the server.
maxFails
- Current max_fails setting of the server.
failTimeout
- Current fail_timeout setting of the server.
backup
- Current backup setting of the server.
down
- Current down setting of the server.
cacheZones
maxSize
- The limit on the maximum size of the cache specified in the configuration.
usedSize
- The current size of the cache.
inBytes
- The total number of bytes received from the cache.
outBytes
- The total number of bytes sent from the cache.
responses
- miss
  - The number of cache miss.
- bypass
  - The number of cache bypass.
- expired
  - The number of cache expired.
- stale
  - The number of cache stale.
- updating
  - The number of cache updating.
- revalidated
  - The number of cache revalidated.
- hit
  - The number of cache hit.
- scarce
  - The number of cache scare.

Json used by control

/{status_uri}/control?cmd=reset&...

/{status_uri}/control?cmd=delete&...

processingReturn
The result of true or false.
processingCommandString
The requested command string.
processingGroupString
The requested group string.
processingZoneString
The requested zone string.
processingCounts
The actual processing number.

Variables

The following embedded variables are provided:

$vts_request_counter
The total number of client requests received from clients.
$vts_in_bytes
The total number of bytes received from clients.
$vts_out_bytes
The total number of bytes sent to clients.
$vts_1xx_counter
The number of responses with status codes 1xx.
$vts_2xx_counter
The number of responses with status codes 2xx.
$vts_3xx_counter
The number of responses with status codes 3xx.
$vts_4xx_counter
The number of responses with status codes 4xx.
$vts_5xx_counter
The number of responses with status codes 5xx.
$vts_cache_miss_counter
The number of cache miss.
$vts_cache_bypass_counter
The number of cache bypass.
$vts_cache_expired_counter
The number of cache expired.
$vts_cache_stale_counter
The number of cache stale.
$vts_cache_updating_counter
The number of cache updating.
$vts_cache_revalidated_counter
The number of cache revalidated.
$vts_cache_hit_counter
The number of cache hit.
$vts_cache_scarce_counter
The number of cache scare.
$vts_request_time
The average of request processing time.

Limit

It is able to limit total traffic per each host by using the directive vhost_traffic_status_limit_traffic. It also is able to limit all traffic by using the directive vhost_traffic_status_limit_traffic_by_set_key. When the limit is exceeded, the server will return the 503 (Service Temporarily Unavailable) error in reply to a request. The return code can be changeable.

To limit traffic for server

http {

    vhost_traffic_status_zone;

    ...

    server {

        server_name *.example.org;

        vhost_traffic_status_limit_traffic in:64G;
        vhost_traffic_status_limit_traffic out:1024G;

        ...
    }
}

Limit in/out total traffic on the *.example.org to 64G and 1024G respectively. It works individually per each domain if vhost_traffic_status_filter_by_host directive is enabled.

To limit traffic for filter

http {
    geoip_country /usr/share/GeoIP/GeoIP.dat;

    vhost_traffic_status_zone;

    ...

    server {

        server_name example.org;

        vhost_traffic_status_filter_by_set_key $geoip_country_code country::$server_name;
        vhost_traffic_status_limit_traffic_by_set_key FG@country::$server_name@US out:1024G;
        vhost_traffic_status_limit_traffic_by_set_key FG@country::$server_name@CN out:2048G;

        ...

    }
}

Limit total traffic of going into US and CN on the example.org to 1024G and 2048G respectively.

To limit traffic for upstream

http {

    vhost_traffic_status_zone;

    ...

    upstream backend {
        server 10.10.10.17:80;
        server 10.10.10.18:80;
    }

    server {

        server_name example.org;

        location /backend {
            vhost_traffic_status_limit_traffic_by_set_key UG@[email protected]:80 in:512G;
            vhost_traffic_status_limit_traffic_by_set_key UG@[email protected]:80 in:1024G;
            proxy_pass http://backend;
        }

        ...

    }
}

Limit total traffic of going into upstream backend on the example.org to 512G and 1024G per each peer.

Caveats: Traffic is the cumulative transfer or counter, not a bandwidth.

Use cases

It is able to calculate the user defined individual stats by using the directive vhost_traffic_status_filter_by_set_key.

To calculate traffic for individual country using GeoIP

http {
    geoip_country /usr/share/GeoIP/GeoIP.dat;

    vhost_traffic_status_zone;
    vhost_traffic_status_filter_by_set_key $geoip_country_code country::*;

    ...

    server {

        ...

        vhost_traffic_status_filter_by_set_key $geoip_country_code country::$server_name;

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }
}

Calculate traffic for individual country of total server groups.
Calculate traffic for individual country of each server groups.

Basically, country flags image is built-in in HTML. The country flags image is enabled if the country string is included in group name which is second argument of vhost_traffic_status_filter_by_set_key directive.

To calculate traffic for individual storage volume

http {
    vhost_traffic_status_zone;

    ...

    server {

        ...

        location ~ ^/storage/(.+)/.*$ {
            set $volume $1;
            vhost_traffic_status_filter_by_set_key $volume storage::$server_name;
        }

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }
}

Calculate traffic for individual storage volume matched by regular expression of location directive.

To calculate traffic for individual user agent

http {
    vhost_traffic_status_zone;

    map $http_user_agent $filter_user_agent {
        default 'unknown';
        ~iPhone ios;
        ~Android android;
        ~(MSIE|Mozilla) windows;
    }

    vhost_traffic_status_filter_by_set_key $filter_user_agent agent::*;

    ...

    server {

        ...

        vhost_traffic_status_filter_by_set_key $filter_user_agent agent::$server_name;

        location /status {
            vhost_traffic_status_display;
            vhost_traffic_status_display_format html;
        }
    }
}

Calculate traffic for individual http_user_agent

Customizing

To customize after the module installed

You need to change the {{uri}} string to your status uri in status.template.html as follows:

shell> vi share/status.template.html

var vtsStatusURI = "yourStatusUri/format/json", vtsUpdateInterval = 1000;

And then, customizing and copy status.template.html to server root directory as follows:

shell> cp share/status.template.html /usr/share/nginx/html/status.html

Configure nginx.conf

   server {
       server_name example.org;
       root /usr/share/nginx/html;

       # Redirect requests for / to /status.html
       location = / {
           return 301 /status.html;
       }

       location = /status.html {}

       # Everything beginning /status (except for /status.html) is
       # processed by the status handler
       location /status {
           vhost_traffic_status_display;
           vhost_traffic_status_display_format json;
       }
   }

Access to your html.

http://example.org/status.html

To customize before the module installed

Modify share/status.template.html (Do not change {{uri}} string)
Recreate the ngx_http_vhost_traffic_status_module_html.h as follows:

shell> cd util
shell> ./tplToDefine.sh ../share/status.template.html > ../src/ngx_http_vhost_traffic_status_module_html.h

Add the module to the build configuration by adding --add-module=/path/to/nginx-module-vts
Build the nginx binary.
Install the nginx binary.

Directives

vhost_traffic_status

| - --- | --- Syntax | vhost_traffic_status <on|off> Default | off Context | http, server, location

Description: Enables or disables the module working. If you set vhost_traffic_status_zone directive, is automatically enabled.

vhost_traffic_status_zone

| - --- | --- Syntax | vhost_traffic_status_zone [shared:name:size] Default | shared:vhost_traffic_status:1m Context | http

Description: Sets parameters for a shared memory zone that will keep states for various keys. The cache is shared between all worker processes.

vhost_traffic_status_display

| - --- | --- Syntax | vhost_traffic_status_display Default | - Context | http, server, location

Description: Enables or disables the module display handler.

vhost_traffic_status_display_format

| - --- | --- Syntax | vhost_traffic_status_display_format <json|html|jsonp> Default | json Context | http, server, location

Description: Sets the display handler's output format. If you set json, will respond with a JSON document. If you set html, will respond with the built-in live dashboard in HTML. If you set jsonp, will respond with a JSONP callback function(default: ngx_http_vhost_traffic_status_jsonp_callback).

vhost_traffic_status_display_jsonp

| - --- | --- Syntax | vhost_traffic_status_display_jsonp callback Default | ngx_http_vhost_traffic_status_jsonp_callback Context | http, server, location

Description: Sets the callback name for the JSONP.

vhost_traffic_status_filter

| - --- | --- Syntax | vhost_traffic_status_filter <on|off> Default | on Context | http, server, location

Description: Enables or disables the filter features.

vhost_traffic_status_filter_by_host

| - --- | --- Syntax | vhost_traffic_status_filter_by_host <on|off> Default | off Context | http, server, location

Description: Enables or disables the keys by Host header field. If you set on and nginx's server_name directive set several or wildcard name starting with an asterisk, e.g. “*.example.org” and requested to server with hostname such as (a|b|c).example.org or *.example.org then json serverZones is printed as follows:

server {
  server_name *.example.org;
  vhost_traffic_status_filter_by_host on;

  ...

}

  ...
  "serverZones": {
      "a.example.org": {
      ...
      },
      "b.example.org": {
      ...
      },
      "c.example.org": {
      ...
      }
      ...
   },
   ...

It provides the same function that set vhost_traffic_status_filter_by_set_key $host.

vhost_traffic_status_filter_by_set_key

| - --- | --- Syntax | vhost_traffic_status_filter_by_set_key key [name] Default | - Context | http, server, location

Description: Enables the keys by user defined variable. The key is a key string to calculate traffic. The name is a group string to calculate traffic. The key and name can contain variables such as $host, $server_name. The name's group belongs to filterZones if specified. The key's group belongs to serverZones if not specified second argument name. The example with geoip module is as follows:

server {
  server_name example.org;
  vhost_traffic_status_filter_by_set_key $geoip_country_code country::$server_name;

  ...

}

  ...
  "serverZones": {
  ...
  },
  "filterZones": {
      "country::example.org": {
          "KR": {
              "requestCounter":...,
              "inBytes":...,
              "outBytes":...,
              "responses":{
                  "1xx":...,
                  "2xx":...,
                  "3xx":...,
                  "4xx":...,
                  "5xx":...,
                  "miss":...,
                  "bypass":...,
                  "expired":...,
                  "stale":...,
                  "updating":...,
                  "revalidated":...,
                  "hit":...,
                  "scarce":...
              },
              "requestMsec":...
          },
          "US": {
          ...
          },
          ...
      },
      ...
  },
  ...

vhost_traffic_status_filter_check_duplicate

| - --- | --- Syntax | vhost_traffic_status_filter_check_duplicate <on|off> Default | on Context | http, server, location

Description: Enables or disables the deduplication of vhost_traffic_status_filter_by_set_key. It is processed only one of duplicate values(key + name) in each directives(http, server, location) if this option is enabled.

vhost_traffic_status_limit

| - --- | --- Syntax | vhost_traffic_status_limit <on|off> Default | on Context | http, server, location

Description: Enables or disables the limit features.

vhost_traffic_status_limit_traffic

| - --- | --- Syntax | vhost_traffic_status_limit_traffic member:size [code] Default | - Context | http, server, location

Description: Enables the traffic limit for specified member. The member is a member string to limit traffic. The size is a size(k/m/g) to limit traffic. The code is a code to return in response to rejected requests.(Default: 503)

The available member strings are as follows:

request
The total number of client requests received from clients.
in
The total number of bytes received from clients.
out
The total number of bytes sent to clients.
1xx
The number of responses with status codes 1xx.
2xx
The number of responses with status codes 2xx.
3xx
The number of responses with status codes 3xx.
4xx
The number of responses with status codes 4xx.
5xx
The number of responses with status codes 5xx.
cache_miss
The number of cache miss.
cache_bypass
The number of cache bypass.
cache_expired
The number of cache expired.
cache_stale
The number of cache stale.
cache_updating
The number of cache updating.
cache_revalidated
The number of cache revalidated.
cache_hit
The number of cache hit.
cache_scarce
The number of cache scare.

vhost_traffic_status_limit_traffic_by_set_key

| - --- | --- Syntax | vhost_traffic_status_limit_traffic_by_set_key key member:size [code] Default | - Context | http, server, location

Description: Enables the traffic limit for specified key and member. The key is a key string to limit traffic. The member is a member string to limit traffic. The size is a size(k/m/g) to limit traffic. The code is a code to return in response to rejected requests.(Default: 503)

The key syntax is as follows:

group@[subgroup@]name

The available group strings are as follows:

NO
The group of server.
UA
The group of upstream alone.
UG
The group of upstream group.(use subgroup)
CC
The group of cache.
FG
The group of filter.(use subgroup)