How-To: Handle large HTTP header size

Configure a larger HTTP read buffer size

Dapr has a default limit of 4KB for the HTTP header read buffer size. If you’re sending HTTP headers larger than the default 4KB, you may encounter a Too big request header service invocation error.

You can increase the HTTP header size by using:

  • The dapr.io/http-read-buffer-size annotation, or
  • The --dapr-http-read-buffer-size flag when using the CLI.

When running in self-hosted mode, use the --dapr-http-read-buffer-size flag to configure Dapr to use non-default http header size:

dapr run --dapr-http-read-buffer-size 16 node app.js

This tells Dapr to set maximum read buffer size to 16 KB.

On Kubernetes, set the following annotations in your deployment YAML:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: default
  labels:
    app: myapp
spec:
  replicas: 1
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
      annotations:
        dapr.io/enabled: "true"
        dapr.io/app-id: "myapp"
        dapr.io/app-port: "8000"
        dapr.io/http-read-buffer-size: "16"
#...

Dapr Kubernetes pod annotations spec

Next steps

Handle large HTTP body requests
Last modified October 22, 2025: feat Jaeger v2 (#4921) (8c5ab7d)