docs/daprdocs/content/en/reference/components-reference/supported-middleware/middleware-rate-limit.md

type	title	linkTitle	description	aliases
docs	Rate limiting	Rate limiting	Use rate limit middleware to limit requests per second	/developing-applications/middleware/supported-middleware/middleware-rate-limit/

The rate limit [HTTP middleware]({{< ref middleware.md >}}) allows restricting the maximum number of allowed HTTP requests per second. Rate limiting can protect your application from Denial of Service (DoS) attacks. DoS attacks can be initiated by malicious 3rd parties but also by bugs in your software (a.k.a. a "friendly fire" DoS attack).

Component format

In the following definition, the maximum requests per second are set to 10:

apiVersion: dapr.io/v1alpha1
kind: Component
metadata:
  name: ratelimit
spec:
  type: middleware.http.ratelimit
  version: v1
  metadata:
  - name: maxRequestsPerSecond
    value: 10

Spec metadata fields

Field	Details	Example
maxRequestsPerSecond	The maximum requests per second by remote IP. The component looks at the X-Forwarded-For and X-Real-IP headers to determine the caller's IP.	10

Once the limit is reached, the requests will fail with HTTP Status code 429: Too Many Requests.

{{% alert title="Important" color="warning" %}} The rate limit is enforced independently in each Dapr sidecar, and not cluster-wide. {{% /alert %}}

Alternatively, the [max concurrency setting]({{< ref control-concurrency.md >}}) can be used to rate-limit applications and applies to all traffic, regardless of remote IP, protocol, or path.

Dapr configuration

To be applied, the middleware must be referenced in [configuration]({{< ref configuration-concept.md >}}). See [middleware pipelines]({{< ref "middleware.md#customize-processing-pipeline">}}).

apiVersion: dapr.io/v1alpha1
kind: Configuration
metadata:
  name: appconfig
spec:
  httpPipeline:
    handlers:
    - name: ratelimit
      type: middleware.http.ratelimit

Related links

• [Control max concurrently]({{< ref control-concurrency.md >}})
• [Middleware]({{< ref middleware.md >}})
• [Dapr configuration]({{< ref configuration-concept.md >}})
• [Configuration overview]({{< ref configuration-overview.md >}})