Service Mirroring in Istio

Service mirroring in Istio is a powerful feature that allows you to replicate the traffic of one service to another service. This is particularly useful in scenarios where you want to test a new version of a service or when you need to troubleshoot issues with a particular service.

Features

• Traffic Replication: Service mirroring allows you to replicate traffic from one service to another, enabling you to test new versions or troubleshoot issues.
• Selective Traffic Routing: You can specify which traffic should be mirrored, allowing for fine-grained control over the traffic flow.
• Transparent to End Users: Service mirroring is transparent to end users, ensuring a seamless experience.

Configuration

To configure service mirroring in Istio, you need to define a ServiceEntry and a VirtualService resource.

ServiceEntry

The ServiceEntry resource defines the external services that are part of your mesh. For example:

apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: external-service
spec:
  hosts:
  - example.com
  ports:
  - number: 80

VirtualService

The VirtualService resource defines how traffic is routed to the services in the mesh. For example:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: service-mirroring
spec:
  hosts:
  - example.com
  http:
  - match:
    - uri:
        prefix: /
    route:
    - destination:
        host: original-service
    - destination:
        host: mirrored-service
      weight: 50

Example

In this example, we have a service called original-service and we want to mirror 50% of the traffic to a new service called mirrored-service.

apiVersion: networking.istio.io/v1alpha3
kind: ServiceEntry
metadata:
  name: external-service
spec:
  hosts:
  - example.com
  ports:
  - number: 80

---
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: service-mirroring
spec:
  hosts:
  - example.com
  http:
  - match:
    - uri:
        prefix: /
    route:
    - destination:
        host: original-service
    - destination:
        host: mirrored-service
      weight: 50

For more information on configuring service mirroring, please refer to the official documentation.

Service Mirroring Architecture