title |
---|
limit-conn |
Limiting request concurrency plugin.
Name | Type | Requirement | Default | Valid | Description |
---|---|---|---|---|---|
conn | integer | required | conn > 0 | the maximum number of concurrent requests allowed. Requests exceeding this ratio (and below conn + burst ) will get delayed(the latency seconds is configured by default_conn_delay ) to conform to this threshold. |
|
burst | integer | required | burst >= 0 | the number of excessive concurrent requests (or connections) allowed to be delayed. | |
default_conn_delay | number | required | default_conn_delay > 0 | the latency seconds of request when concurrent requests exceeding conn but below (conn + burst ). |
|
only_use_default_delay | boolean | optional | false | [true,false] | enable the strict mode of the latency seconds. If you set this option to true , it will run strictly according to the latency seconds you set without additional calculation logic. |
key_type | string | optional | "var" | ["var", "var_combination"] | the type of key. |
key | string | required | the user specified key to limit the rate. If the key_type is "var", the key will be treated as a name of variable, like "remote_addr" or "consumer_name". If the key_type is "var_combination", the key will be a combination of variables, like "$remote_addr $consumer_name". If the value of the key is empty, remote_addr will be set as the default key. |
||
rejected_code | string | optional | 503 | [200,...,599] | the HTTP status code returned when the request exceeds conn + burst will be rejected. |
rejected_msg | string | optional | non-empty | the response body returned when the request exceeds conn + burst will be rejected. |
|
allow_degradation | boolean | optional | false | Whether to enable plugin degradation when the limit-conn function is temporarily unavailable. Allow requests to continue when the value is set to true, default false. |
Here's an example, enable the limit-conn plugin on the specified route when setting key_type
to var
:
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"methods": ["GET"],
"uri": "/index.html",
"plugins": {
"limit-conn": {
"conn": 1,
"burst": 0,
"default_conn_delay": 0.1,
"rejected_code": 503,
"key_type": "var",
"key": "http_a"
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"39.97.63.215:80": 1
}
}
}'
Here's an example, enable the limit-conn plugin on the specified route when setting key_type
to var_combination
:
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"methods": ["GET"],
"uri": "/index.html",
"plugins": {
"limit-conn": {
"conn": 1,
"burst": 0,
"default_conn_delay": 0.1,
"rejected_code": 503,
"key_type": "var_combination",
"key": "$consumer_name $remote_addr"
}
},
"upstream": {
"type": "roundrobin",
"nodes": {
"39.97.63.215:80": 1
}
}
}'
You also can complete the above operation through the web interface, first add a route, then add limit-conn plugin:
The parameters of the plugin enabled above indicate that only one concurrent request is allowed. When more than one concurrent request is received, will return 503
directly.
curl -i http://127.0.0.1:9080/index.html?sleep=20 &
curl -i http://127.0.0.1:9080/index.html?sleep=20
<html>
<head><title>503 Service Temporarily Unavailable</title></head>
<body>
<center><h1>503 Service Temporarily Unavailable</h1></center>
<hr><center>openresty</center>
</body>
</html>
This means that the limit request concurrency plugin is in effect.
When you want to disable the limit-conn plugin, it is very simple, you can delete the corresponding json configuration in the plugin configuration, no need to restart the service, it will take effect immediately:
curl http://127.0.0.1:9080/apisix/admin/routes/1 -H 'X-API-KEY: edd1c9f034335f136f87ad84b625c8f1' -X PUT -d '
{
"methods": ["GET"],
"uri": "/index.html",
"id": 1,
"plugins": {
},
"upstream": {
"type": "roundrobin",
"nodes": {
"39.97.63.215:80": 1
}
}
}'
The limit-conn plugin has been disabled now. It works for other plugins.