This topic describes how to shape traffic to gRPC servers based on the gRPC version and gRPC API in the Alibaba Cloud Service Mesh (ASM) console.

Shape traffic to gRPC servers based on the gRPC version

A gRPC service is deployed on each of the Java, Go, Node.js, and Python gRPC servers. The following example shows how to route requests from gRPC clients to the gRPC service that is deployed on the Java gRPC server.Version
  1. Log on to the ASM console.
  2. In the left-side navigation pane, choose Service Mesh > Mesh Management.
  3. On the Mesh Management page, click the name of the ASM instance that you want to manage. Alternatively, click Manage in the Actions column of the ASM instance.
  4. In the Control Plane section, click the DestinationRule tab and then Create.
  5. In the Create panel, select the required namespace from the Namespaces drop-down list. Copy the following content to the code editor. Then, click OK.
    apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  namespace: grpc-best
  name: grpc-server-dr
spec:
  host: grpc-server-svc
  subsets:
    - name: v1
      labels:
        version: v1
    - name: v2
      labels:
        version: v2
    - name: v3
      labels:
        version: v3
    - name: v4
      labels:
        version: v4
  6. In the Control Plane section, click the VirtualService tab and then Create.
  7. In the Create panel, select the required namespace from the Namespaces drop-down list. Copy the following content to the code editor. Then, click OK.
    apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  namespace: grpc-best
  name: grpc-server-vs
spec:
  hosts:
    - "*"
  gateways:
    - grpc-gateway
  http:
    - match:
        - port: 9996
      route:
        - destination:
            host: grpc-server-svc
            subset: v1
          weight: 100
    Run the following command to check whether all the requests are routed to the Java gRPC service:
    for i in {1..100}; do
  docker exec -e GRPC_SERVER="${INGRESS_IP}" -it "$client_node_container" node mesh_client.js >> mesh_result
done
sort mesh_result | grep -v "^[[:space:]]*$"| uniq -c | sort -nrk1
    Expected output:
     100 TalkOneAnswerMore:JAVA
 100 TalkMoreAnswerOne:JAVA
 100 TalkBidirectional:JAVA
 100 Talk:JAVA

Shape traffic to gRPC servers by using the gRPC API operations

You can use the gRPC API operations to shape traffic to gRPC servers in a fine-grained way. The gRPC API operations can be built for the communication models. For more information, see Implement the communication models of gRPC. Four gRPC API operations and four gRPC services in the following programming languages are available: Java, Go, Node.js, and Python. The following example shows how to set a routing rule to route the requests of a gRPC API operation to the gRPC server that uses the same language as the operation.API
  1. Log on to the ASM console.
  2. In the left-side navigation pane, choose Service Mesh > Mesh Management.
  3. On the Mesh Management page, click the name of the ASM instance that you want to manage. Alternatively, click Manage in the Actions column of the ASM instance.
  4. In the Control Plane section, click the VirtualService tab and then Create.
  5. In the Create panel, select the required namespace from the Namespaces drop-down list. Copy the following content to the code editor. Then, click OK.
    apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  namespace: grpc-best
  name: grpc-server-vs
spec:
  hosts:
    - "*"
  gateways:
    - grpc-gateway
  http:
    - match:
        - port: 9996
        - uri:
            exact: /org.feuyeux.grpc.LandingService/talk
      route:
        - destination:
            host: grpc-server-svc
            subset: v1
          weight: 100
    - match:
        - port: 9996
        - uri:
            exact: /org.feuyeux.grpc.LandingService/talkOneAnswerMore
      route:
        - destination:
            host: grpc-server-svc
            subset: v2
          weight: 100
    - match:
        - port: 9996
        - uri:
            exact: /org.feuyeux.grpc.LandingService/talkMoreAnswerOne
      route:
        - destination:
            host: grpc-server-svc
            subset: v3
          weight: 100
    - match:
        - port: 9996
        - uri:
            exact: /org.feuyeux.grpc.LandingService/talkBidirectional
      route:
        - destination:
            host: grpc-server-svc
            subset: v4
          weight: 100
    Run the following command to check whether the requests of each gRPC API operation are directed to the gRPC server that uses the same language as the operation:
    for i in {1..100}; do
  docker exec -e GRPC_SERVER="${INGRESS_IP}" -it "$client_node_container" node mesh_client.js >> mesh_result
done
sort mesh_result | grep -v "^[[:space:]]*$"| uniq -c | sort -nrk1
    Expected output:
     100 TalkOneAnswerMore:GOLANG
 100 TalkMoreAnswerOne:NODEJS
 100 TalkBidirectional:PYTHON
 100 Talk:JAVA