Rate Limiting plugin

Rate limit how many HTTP requests can be made in a given period of seconds, minutes, hours, days, months, or years. If the underlying Service/Route (or deprecated API entity) has no authentication layer, the Client IP address will be used; otherwise, the Consumer will be used if an authentication plugin has been configured.

Tip: The Rate Limiting Advanced plugin provides the ability to apply multiple limits in sliding or fixed windows.

Configuration Reference

This plugin is partially compatible with DB-less mode.

In DB-less mode, you configure Kong Gateway declaratively. Therefore, the Admin API is mostly read-only. The only tasks it can perform are all related to handling the declarative config, including:

Setting a target's health status in the load balancer
Validating configurations against schemas
Uploading the declarative configuration using the /config endpoint

The plugin will run fine with the local policy (which doesn’t use the database) or the redis policy (which uses an independent Redis, so it is compatible with DB-less).

The plugin will not work with the cluster policy, which requires writes to the database.

Example plugin configuration

Enable on a service

Enable on a route

Enable on a consumer

Enable globally

The following examples provide some typical configurations for enabling the rate-limiting plugin on a service.

Admin API

Kubernetes

Declarative (YAML)

Konnect Cloud

Kong Manager

Make the following request:

curl -X POST http://{HOST}:8001/services/{SERVICE}/plugins \
    --data "name=rate-limiting"  \
    --data "config.second=5" \
    --data "config.hour=10000" \
    --data "config.policy=local" \
    --data "config.fault_tolerant=true" \
    --data "config.hide_client_headers=false" \
    --data "config.redis_ssl=false" \
    --data "config.redis_ssl_verify=false"

SERVICE is the id or name of the service that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <rate-limiting-example>
config: 
  second: 5
  hour: 10000
  policy: local
  fault_tolerant: true
  hide_client_headers: false
  redis_ssl: false
  redis_ssl_verify: false
plugin: rate-limiting

Next, apply the KongPlugin resource to a Service by annotating the Service as follows:

apiVersion: v1
kind: Service
metadata:
  name: {SERVICE}
  labels:
    app: {SERVICE}
  annotations:
    konghq.com/plugins: <rate-limiting-example>
spec:
  ports:
  - port: 80
    targetPort: 80
    protocol: TCP
    name: {SERVICE}
  selector:
    app: {SERVICE}

{SERVICE} is the id or name of the service that this plugin configuration will target.

Note: The KongPlugin resource only needs to be defined once and can be applied to any service, consumer, or route in the namespace. If you want the plugin to be available cluster-wide, create the resource as a KongClusterPlugin instead of KongPlugin.

Add this section to your declarative configuration file:

plugins:
- name: rate-limiting
  service: {SERVICE}
  config: 
    second: 5
    hour: 10000
    policy: local
    fault_tolerant: true
    hide_client_headers: false
    redis_ssl: false
    redis_ssl_verify: false

SERVICE is the id or name of the service that this plugin configuration will target.

In Konnect Cloud, select the service on the ServiceHub page.
Scroll down to Versions and select the version.
Scroll down to Plugins and click New Plugin.
Find and select the Rate Limiting plugin.
Enter the following parameters, updating the default or sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

In Kong Manager, select the workspace.
From the Dashboard, scroll down to Services and click View for the service row.
Scroll down to plugins and click Add Plugin.
Find and select the Rate Limiting plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, select Scoped.
Add the service name and ID to the Service field if it is not already prefilled.
Enter the following parameters, updating the default or sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

The following examples provide some typical configurations for enabling the rate-limiting plugin on a route.

Admin API

Kubernetes

Declarative (YAML)

Konnect Cloud

Kong Manager

Make the following request:

$ curl -X POST http://{HOST}:8001/routes/{ROUTE}/plugins \
    --data "name=rate-limiting"  \
    --data "config.second=5" \
    --data "config.hour=10000" \
    --data "config.policy=local" \
    --data "config.fault_tolerant=true" \
    --data "config.hide_client_headers=false" \
    --data "config.redis_ssl=false" \
    --data "config.redis_ssl_verify=false"

ROUTE is the id or name of the route that this plugin configuration will target.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <rate-limiting-example>
config: 
  second: 5
  hour: 10000
  policy: local
  fault_tolerant: true
  hide_client_headers: false
  redis_ssl: false
  redis_ssl_verify: false
plugin: rate-limiting

Then, apply it to an ingress (Route or Routes) by annotating the ingress as follows:

apiVersion: networking/v1beta1
kind: Ingress
metadata:
  name: {ROUTE}
  annotations:
    kubernetes.io/ingress.class: kong
    konghq.com/plugins: <rate-limiting-example>
spec:
  rules:
  - host: examplehostname.com
    http:
      paths:
      - path: /bar
        backend:
          serviceName: echo
          servicePort: 80

ROUTE is the id or name of the route that this plugin configuration will target.

Add this section to your declarative configuration file:

plugins:
- name: rate-limiting
  route: <route>
  config: 
    second: 5
    hour: 10000
    policy: local
    fault_tolerant: true
    hide_client_headers: false
    redis_ssl: false
    redis_ssl_verify: false

ROUTE is the id or name of the route that this plugin configuration will target.

In Konnect Cloud, select the service from the ServiceHub page.
Scroll down to Versions and select the version.
Select the route.
Scroll down to Plugins and click Add Plugin.
Find and select the Rate Limiting plugin.
Enter the following parameters, updating the default or sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

In Kong Manager, select the workspace.
From the Dashboard, select Routes in the left navigation.
Click View for the route row.
Scroll down to plugins and click Add Plugin.
Find and select the Rate Limiting plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, select Scoped.
Add the Route ID if it is not already prefilled.
Enter the following parameters, updating the default or sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

The following examples provide some typical configurations for enabling the rate-limiting plugin on a consumer.

Admin API

Kubernetes

Declarative (YAML)

Kong Manager

Make the following request:

$ curl -X POST http://{HOST}:8001/consumers/{CONSUMER}/plugins \
    --data "name=rate-limiting"  \
    --data "config.second=5" \
    --data "config.hour=10000" \
    --data "config.policy=local" \
    --data "config.fault_tolerant=true" \
    --data "config.hide_client_headers=false" \
    --data "config.redis_ssl=false" \
    --data "config.redis_ssl_verify=false"

CONSUMER is the id or username of the consumer that this plugin configuration will target.

You can combine consumer.id, service.id, or route.id in the same request, to further narrow the scope of the plugin.

First, create a KongPlugin resource:

apiVersion: configuration.konghq.com/v1
kind: KongPlugin
metadata:
  name: <rate-limiting-example>
config: 
  second: 5
  hour: 10000
  policy: local
  fault_tolerant: true
  hide_client_headers: false
  redis_ssl: false
  redis_ssl_verify: false
plugin: rate-limiting

Then, apply it to a consumer by annotating the KongConsumer resource as follows:

apiVersion: configuration.konghq.com/v1
kind: KongConsumer
metadata:
  name: {CONSUMER}
  annotations:
    konghq.com/plugins: <rate-limiting-example>
    kubernetes.io/ingress.class: kong

CONSUMER is the id or username of the consumer that this plugin configuration will target.

Note: The KongPlugin resource only needs to be defined once and can be applied to any Service, Consumer, or Route in the namespace. If you want the plugin to be available cluster-wide, create the resource as a KongClusterPlugin instead of KongPlugin.

Add this section to your declarative configuration file:

plugins:
- name: rate-limiting
  consumer: {CONSUMER}
  config: 
    second: 5
    hour: 10000
    policy: local
    fault_tolerant: true
    hide_client_headers: false
    redis_ssl: false
    redis_ssl_verify: false

CONSUMER is the id or username of the consumer that this plugin configuration will target.

In Kong Manager, select the workspace.
From the Dashboard, scroll down to Consumers and click View for the consumer row.
Select the Plugins tab.
Click Add Plugin.
Find and select the Rate Limiting plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, select Global.
Enter the following parameters, updating the default or sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

A plugin which is not associated to any service, route, or consumer is considered global, and will be run on every request. Read the Plugin Reference and the Plugin Precedence sections for more information.

The following examples provide some typical configurations for enabling the rate-limiting plugin globally.

Admin API

Kubernetes

Declarative (YAML)

Kong Manager

Make the following request:

$ curl -X POST http://{HOST}:8001/plugins/ \
    --data "name=rate-limiting"  \
    --data "config.second=5" \
    --data "config.hour=10000" \
    --data "config.policy=local" \
    --data "config.fault_tolerant=true" \
    --data "config.hide_client_headers=false" \
    --data "config.redis_ssl=false" \
    --data "config.redis_ssl_verify=false"

Create a KongClusterPlugin resource and label it as global:

apiVersion: configuration.konghq.com/v1
kind: KongClusterPlugin
metadata:
  name: <global-rate-limiting>
  annotations:
    kubernetes.io/ingress.class: kong
  labels:
    global: \"true\"
config: 
  second: 5
  hour: 10000
  policy: local
  fault_tolerant: true
  hide_client_headers: false
  redis_ssl: false
  redis_ssl_verify: false
plugin: rate-limiting

Add a plugins entry in the declarative configuration file:

plugins:
- name: rate-limiting
  config: 
    second: 5
    hour: 10000
    policy: local
    fault_tolerant: true
    hide_client_headers: false
    redis_ssl: false
    redis_ssl_verify: false

In Kong Manager, select the workspace.
From the Dashboard, select Plugins in the left navigation.
Click New Plugin.
Find and select the Rate Limiting plugin.

Note: If the plugin is greyed out, then it is not available for your product tier. See Kong Gateway tiers.
If the option is available, set the plugin scope to Global.
Enter the following parameters, updating the default/sample values as needed:
- Config.Fault Tolerant: select checkbox
- Config.Hide Client Headers: clear checkbox
- Config.Redis Ssl: clear checkbox
- Config.Redis Ssl Verify: clear checkbox
Click Create.

Parameters

Here's a list of all the parameters which can be used in this plugin's configuration:

Form Parameter	Description
`name` required Type: string	The name of the plugin, in this case `rate-limiting`.
`service.id` Type: string	The ID of the Service the plugin targets.
`route.id` Type: string	The ID of the Route the plugin targets.
`consumer.id` Type: string	The ID of the Consumer the plugin targets.
`enabled` required Type: boolean Default value: `true`	Whether this plugin will be applied.
`config.second` semi-optional Type: number	The number of HTTP requests that can be made per second.
`config.minute` semi-optional Type: number	The number of HTTP requests that can be made per minute.
`config.hour` semi-optional Type: number	The number of HTTP requests that can be made per hour.
`config.day` semi-optional Type: number	The number of HTTP requests that can be made per day.
`config.month` semi-optional Type: number	The number of HTTP requests that can be made per month.
`config.year` semi-optional Type: number	The number of HTTP requests that can be made per year.
`config.limit_by` optional Type: string Default value: `consumer`	The entity that will be used when aggregating the limits: `consumer`, `credential`, `ip`, `service`, `header`, `path`. If the value for the entity chosen to aggregate the limit cannot be determined, the system will always fallback to `ip`. If value `service` is chosen, the `service_id` configuration must be provided. If value `header` is chosen, the `header_name` configuration must be provided. If value `path` is chosen, the `path` configuration must be provided.
`config.service_id` semi-optional Type: string	The service id to be used if `limit_by` is set to `service`.
`config.header_name` semi-optional Type: string	Header name to be used if `limit_by` is set to `header`.
`config.path` semi-optional Type: string	Path to be used if `limit_by` is set to `path`.
`config.policy` optional Type: string Default value: `cluster`	The rate-limiting policies to use for retrieving and incrementing the limits. Available values are: `local`: Counters are stored locally in-memory on the node. `cluster`: Counters are stored in the Kong datastore and shared across the nodes. `redis`: Counters are stored on a Redis server and shared across the nodes. In DB-less and hybrid modes, the `cluster` config policy is not supported. For DB-less mode, use one of `redis` or `local`; for hybrid mode, use `redis`, or `local` for data planes only. In Konnect Cloud, the default policy is `redis`. For details on which policy should be used, refer to the implementation considerations.
`config.fault_tolerant` required Type: boolean Default value: `true`	A boolean value that determines if the requests should be proxied even if Kong has troubles connecting a third-party datastore. If `true`, requests will be proxied anyway, effectively disabling the rate-limiting function until the datastore is working again. If `false`, then the clients will see `500` errors.
`config.hide_client_headers` required Type: boolean Default value: `false`	Optionally hide informative response headers.
`config.redis_host` semi-optional Type: string	When using the `redis` policy, this property specifies the address to the Redis server.
`config.redis_port` optional Type: integer Default value: `6379`	When using the `redis` policy, this property specifies the port of the Redis server. By default is `6379`.
`config.redis_username` optional Type: string	When using the `redis` policy, this property specifies the username to connect to the Redis server when ACL authentication is desired.
`config.redis_password` optional Type: string	When using the `redis` policy, this property specifies the password to connect to the Redis server.
`config.redis_ssl` required Type: boolean Default value: `false`	When using the `redis` policy, this property specifies if SSL is used to connect to the Redis server.
`config.redis_ssl_verify` required Type: boolean Default value: `false`	When using the `redis` policy with `redis_ssl` set to `true`, this property specifies it server SSL certificate is validated. Note that you need to configure the lua_ssl_trusted_certificate to specify the CA (or server) certificate used by your Redis server. You may also need to configure lua_ssl_verify_depth accordingly.
`config.redis_server_name` optional Type: string	When using the `redis` policy with `redis_ssl` set to `true`, this property specifies the server name for the TLS extension Server Name Indication (SNI)
`config.redis_timeout` optional Type: number Default value: `2000`	When using the `redis` policy, this property specifies the timeout in milliseconds of any command submitted to the Redis server.
`config.redis_database` optional Type: integer Default value: `0`	When using the `redis` policy, this property specifies the Redis database to use.

Note: At least one limit (`second`, `minute`, `hour`, `day`, `month`, `year`) must be configured. Multiple limits can be configured.

Headers sent to the client

When this plugin is enabled, Kong sends additional headers to show the allowed limits, number of available requests, and the time remaining (in seconds) until the quota is reset. Here’s an example header:

RateLimit-Limit: 6
RateLimit-Remaining: 4
RateLimit-Reset: 47

The plugin also sends headers to show the time limit and the minutes still available:

X-RateLimit-Limit-Minute: 10
X-RateLimit-Remaining-Minute: 9

If more than one time limit is set, the header contains all of these:

X-RateLimit-Limit-Second: 5
X-RateLimit-Remaining-Second: 4
X-RateLimit-Limit-Minute: 10
X-RateLimit-Remaining-Minute: 9

When a limit is reached, the plugin returns an HTTP/1.1 429 status code, with the following JSON body:

{ "message": "API rate limit exceeded" }

Warning: The headers RateLimit-Limit, RateLimit-Remaining, and RateLimit-Reset are based on the Internet-Draft RateLimit Header Fields for HTTP. These could change if the specification is updated.

Implementation considerations

The plugin supports three policies.

Policy	Pros	Cons
`cluster`	Accurate, no extra components to support.	Each request forces a read and a write on the datastore. Therefore, relatively, the biggest performance impact.
`redis`	Accurate, less performance impact than a `cluster` policy.	Needs a Redis installation. Bigger performance impact than a `local` policy.
`local`	Minimal performance impact.	Less accurate. Unless there’s a consistent-hashing load balancer in front of Kong, it diverges when scaling the number of nodes.

Two common use cases are:

Every transaction counts. The highest level of accuracy is needed. An example is a transaction with financial consequences.
Backend protection. Accuracy is not as relevant. The requirement is only to protect backend services from overloading that’s caused either by specific users or by attacks.

Note: Enterprise-Only: The Kong Community Edition of this Rate Limiting plugin does not include Redis Sentinel support. Only Kong Gateway Subscription customers can use Redis Sentinel with Kong Rate Limiting, enabling them to deliver highly available primary-replica deployments.

Every transaction counts

In this scenario, because accuracy is important, the local policy is not an option. Consider the support effort you might need for Redis, and then choose either cluster or redis.

You could start with the cluster policy, and move to redis if performance reduces drastically.

Do remember that you cannot port the existing usage metrics from the datastore to Redis. This might not be a problem with shortlived metrics (for example, seconds or minutes) but if you use metrics with a longer time frame (for example, months), plan your switch carefully.

Backend protection

If accuracy is of lesser importance, choose the local policy. You might need to experiment a little before you get a setting that works for your scenario. As the cluster scales to more nodes, more user requests are handled. When the cluster scales down, the probability of false negatives increases. So, adjust your limits when scaling.

For example, if a user can make 100 requests every second, and you have an equally balanced 5-node Kong cluster, setting the local limit to something like 30 requests every second should work. If you see too many false negatives, increase the limit.

To minimise inaccuracies, consider using a consistent-hashing load balancer in front of Kong. The load balancer ensures that a user is always directed to the same Kong node, thus reducing inaccuracies and preventing scaling problems.

Fallback to IP

When the selected policy cannot be retrieved, the plugin falls back to limiting usage by identifying the IP address. This can happen for several reasons, such as the selected header was not sent by the client or the configured service was not found.

Changelog

Kong Gateway 2.8.x (plugin version 2.3.1)

Added the redis_username configuration parameter.

Kong Gateway 2.7.x (plugin version 2.3.0)

Added the redis_ssl, redis_ssl_verify, and redis_server_name configuration parameters.

About this Plugin
Plugin Version	2.3.x
Made by	Kong Inc.
Categories	Traffic Control
DB-less compatible?	Partially
Konnect Cloud compatible?	Yes
Compatible protocols	`http` `https`
Version Compatibility
Kong Gateway 2.8.x 2.7.x Kong Gateway (OSS) 2.8.x 2.7.x