Alibaba Cloud Service Mesh：通過配置ASMHeaderPropagation實現寬鬆模式的流量泳道

前提條件

• 已建立ASM企業版或旗艦版執行個體，且執行個體版本為1.21.6.54及以上。具體操作，請參見建立ASM執行個體或升級ASM執行個體。

• 已添加Kubernetes叢集到ASM執行個體。具體操作，請參見添加叢集到ASM執行個體。

• 已建立名稱為ingressgateway的ASM網關。具體操作，請參見建立入口網關。

功能介紹

Baggage是OpenTelemetry推出的一種標準化機制,旨在實現分布式系統調用鏈路中跨進程傳遞上下文資訊。它通過在HTTP頭部增加名為“Baggage”的欄位實現，欄位值為索引值對格式，可傳遞租戶ID、追蹤ID、安全憑證等上下文資料，支援鏈路追蹤、日誌關聯等功能而無需修改代碼。例如：

baggage: userId=alice,serverNode=DF%2028,isProduction=false

基於透傳的Baggage上下文資訊，服務網格ASM可以利用ASMHeaderPropagation資源協助您在服務調用鏈路上透傳任意要求標頭、並基於該要求標頭實現寬鬆模式的流量泳道。有關寬鬆模式的流量泳道，請參見流量泳道概述。

步驟一：佈建服務透傳Baggage上下文

本節主要展示如何通過OpenTelemetry Operator自動插裝的方法，為Kubernetes叢集中的服務添加Baggage透傳能力。

1. 部署OpenTelemetry Operator。

   1. 通過kubectl串連到ASM執行個體添加的Kubernetes叢集。執行以下命令，建立opentelemetry-operator-system命名空間。

      kubectl create namespace opentelemetry-operator-system

   2. 執行以下命令，使用Helm在opentelemetry-operator-system命名空間下安裝OpenTelemetry Operator。（關於Helm安裝步驟，請參見安裝Helm）

      helm repo add open-telemetry https://open-telemetry.github.io/opentelemetry-helm-charts
      helm install  \
          --namespace=opentelemetry-operator-system \
          --version=0.46.0 \
          --set admissionWebhooks.certManager.enabled=false \
          --set admissionWebhooks.certManager.autoGenerateCert=true \
          --set manager.image.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/opentelemetry-operator" \
          --set manager.image.tag="0.92.1" \
          --set kubeRBACProxy.image.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/kube-rbac-proxy" \
          --set kubeRBACProxy.image.tag="v0.13.1" \
          --set manager.collectorImage.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/opentelemetry-collector" \
          --set manager.collectorImage.tag="0.97.0" \
          --set manager.opampBridgeImage.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/operator-opamp-bridge" \
          --set manager.opampBridgeImage.tag="0.97.0" \
          --set manager.targetAllocatorImage.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/target-allocator" \
          --set manager.targetAllocatorImage.tag="0.97.0" \
          --set manager.autoInstrumentationImage.java.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/autoinstrumentation-java" \
          --set manager.autoInstrumentationImage.java.tag="1.32.1" \
          --set manager.autoInstrumentationImage.nodejs.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/autoinstrumentation-nodejs" \
          --set manager.autoInstrumentationImage.nodejs.tag="0.49.1" \
          --set manager.autoInstrumentationImage.python.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/autoinstrumentation-python" \
          --set manager.autoInstrumentationImage.python.tag="0.44b0" \
          --set manager.autoInstrumentationImage.dotnet.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/autoinstrumentation-dotnet" \
          --set manager.autoInstrumentationImage.dotnet.tag="1.2.0" \
          --set manager.autoInstrumentationImage.go.repository="registry-cn-hangzhou.ack.aliyuncs.com/acs/opentelemetry-go-instrumentation" \
          --set manager.autoInstrumentationImage.go.tag="v0.10.1.alpha-2-aliyun" \
          opentelemetry-operator open-telemetry/opentelemetry-operator

   3. 執行以下命令，檢查opentelemetry-operator是否正常運行。

      kubectl get pod -n opentelemetry-operator-system

      預期輸出：

      NAME                                      READY   STATUS    RESTARTS   AGE
      opentelemetry-operator-854fb558b5-pvllj   2/2     Running   0          1m

2. 配置自動插裝（auto-instrumentation）。

   1. 使用以下內容，建立instrumentation.yaml檔案。

      apiVersion: opentelemetry.io/v1alpha1
      kind: Instrumentation
      metadata:
        name: demo-instrumentation
      spec:
        propagators:
          - baggage
        sampler:
          type: parentbased_traceidratio
          argument: "1"

   2. 執行以下命令，在default命名空間下聲明自動插裝。

      kubectl apply -f instrumentation.yaml

      說明

      對於OpenTelemetry架構來說，其最佳實務還包括部署OpenTelemetry Collector以收集可觀測資料。由於本文主要示範OpenTelemetry自動插裝實現的Baggage鏈路透傳，因此沒有包含部署OpenTelemetry Collector的步驟。有關服務網格ASM如何通過OpenTelemetry上報鏈路追蹤資料，請參考見將鏈路追蹤資料擷取到阿里雲可觀測鏈路OpenTelemetry版。

步驟二：部署樣本服務

1. 為default命名空間啟用Sidecar網格代理自動注入。具體操作，請參見管理全域命名空間。

   說明

   關於自動注入的更多資訊，請參見配置Sidecar注入策略。

2. 使用以下內容，建立mock.yaml檔案。

   展開查看mock.yaml內容

   apiVersion: v1
   kind: Service
   metadata:
     name: mocka
     labels:
       app: mocka
       service: mocka
   spec:
     ports:
     - port: 8000
       name: http
     selector:
       app: mocka
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mocka-v1
     labels:
       app: mocka
       version: v1
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mocka
         version: v1
         ASM_TRAFFIC_TAG: v1
     template:
       metadata:
         labels:
           app: mocka
           version: v1
           ASM_TRAFFIC_TAG: v1
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v1
           - name: app
             value: mocka
           - name: upstream_url
             value: "http://mockb:8000/"
           ports:
           - containerPort: 8000
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: mockb
     labels:
       app: mockb
       service: mockb
   spec:
     ports:
     - port: 8000
       name: http
     selector:
       app: mockb
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockb-v1
     labels:
       app: mockb
       version: v1
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockb
         version: v1
         ASM_TRAFFIC_TAG: v1
     template:
       metadata:
         labels:
           app: mockb
           version: v1
           ASM_TRAFFIC_TAG: v1
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v1
           - name: app
             value: mockb
           - name: upstream_url
             value: "http://mockc:8000/"
           ports:
           - containerPort: 8000
   
   ---
   apiVersion: v1
   kind: Service
   metadata:
     name: mockc
     labels:
       app: mockc
       service: mockc
   spec:
     ports:
     - port: 8000
       name: http
     selector:
       app: mockc
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockc-v1
     labels:
       app: mockc
       version: v1
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockc
         version: v1
         ASM_TRAFFIC_TAG: v1
     template:
       metadata:
         labels:
           app: mockc
           version: v1
           ASM_TRAFFIC_TAG: v1
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v1
           - name: app
             value: mockc
           ports:
           - containerPort: 8000
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mocka-v2
     labels:
       app: mocka
       version: v2
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mocka
         version: v2
         ASM_TRAFFIC_TAG: v2
     template:
       metadata:
         labels:
           app: mocka
           version: v2
           ASM_TRAFFIC_TAG: v2
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v2
           - name: app
             value: mocka
           - name: upstream_url
             value: "http://mockb:8000/"
           ports:
           - containerPort: 8000
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockb-v2
     labels:
       app: mockb
       version: v2
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockb
         version: v2
         ASM_TRAFFIC_TAG: v2
     template:
       metadata:
         labels:
           app: mockb
           version: v2
           ASM_TRAFFIC_TAG: v2
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v2
           - name: app
             value: mockb
           - name: upstream_url
             value: "http://mockc:8000/"
           ports:
           - containerPort: 8000
   
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockc-v2
     labels:
       app: mockc
       version: v2
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockc
         version: v2
         ASM_TRAFFIC_TAG: v2
     template:
       metadata:
         labels:
           app: mockc
           version: v2
           ASM_TRAFFIC_TAG: v2
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v2
           - name: app
             value: mockc
           ports:
           - containerPort: 8000
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mocka-v3
     labels:
       app: mocka
       version: v3
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mocka
         version: v3
         ASM_TRAFFIC_TAG: v3
     template:
       metadata:
         labels:
           app: mocka
           version: v3
           ASM_TRAFFIC_TAG: v3
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v3
           - name: app
             value: mocka
           - name: upstream_url
             value: "http://mockb:8000/"
           ports:
           - containerPort: 8000
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockb-v3
     labels:
       app: mockb
       version: v3
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockb
         version: v3
         ASM_TRAFFIC_TAG: v3
     template:
       metadata:
         labels:
           app: mockb
           version: v3
           ASM_TRAFFIC_TAG: v3
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v3
           - name: app
             value: mockb
           - name: upstream_url
             value: "http://mockc:8000/"
           ports:
           - containerPort: 8000
   
   ---
   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: mockc-v3
     labels:
       app: mockc
       version: v3
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: mockc
         version: v3
         ASM_TRAFFIC_TAG: v3
     template:
       metadata:
         labels:
           app: mockc
           version: v3
           ASM_TRAFFIC_TAG: v3
         annotations:
           instrumentation.opentelemetry.io/inject-java: "true"
           instrumentation.opentelemetry.io/container-names: "default"
       spec:
         containers:
         - name: default
           image: registry-cn-hangzhou.ack.aliyuncs.com/acs/asm-mock:v0.1-java
           imagePullPolicy: IfNotPresent
           env:
           - name: version
             value: v3
           - name: app
             value: mockc
           ports:
           - containerPort: 8000

   對於每個執行個體服務Pod，都加入了instrumentation.opentelemetry.io/inject-java: "true"和instrumentation.opentelemetry.io/container-names: "default"兩個註解，以聲明該執行個體服務使用Java語言實現，並要求OpenTelemetry Operator對名稱為default的容器進行自動插裝。

3. 執行以下命令，部署執行個體服務。

   kubectl apply -f mock.yaml

   基於OpenTelemetry自動插裝機制，部署的服務Pod將自動具有在調用鏈路中傳遞Baggage的能力。

步驟三：建立流量規則實現寬鬆模式流量泳道

1. 建立DestinationRule流量規則。

   1. 使用以下內容，建立dr-mock.yaml檔案。

      展開查看YAML內容

      apiVersion: networking.istio.io/v1beta1
      kind: DestinationRule
      metadata:
        name: dr-mock-default-mocka
      spec:
        host: mocka.default.svc.cluster.local
        subsets:
          - labels:
              version: v1
            name: v1
          - labels:
              version: v2
            name: v2
          - labels:
              version: v3
            name: v3
      ---
      apiVersion: networking.istio.io/v1beta1
      kind: DestinationRule
      metadata:
        name: dr-mock-default-mockb
      spec:
        host: mockb.default.svc.cluster.local
        subsets:
          - labels:
              version: v1
            name: v1
          - labels:
              version: v3
            name: v3
      ---
      apiVersion: networking.istio.io/v1beta1
      kind: DestinationRule
      metadata:
        name: dr-mock-default-mockc
      spec:
        host: mockc.default.svc.cluster.local
        subsets:
          - labels:
              version: v1
            name: v1
          - labels:
              version: v2
            name: v2

      此檔案表示將mocka、mockb、mockc三個服務按照Pod的version標籤分為v1、v2、v3三個版本子集，其中mocka有v1、v2、v3三個版本，mockb有v1、v3兩個版本，mockc有v1、v2兩個版本。

   2. 通過kubectl串連ASM執行個體，執行以下命令，建立DestinationRule流量規則。

      kuebctl apply -f dr-mock.yaml

2. 建立ASMHeaderPropagation流量規則。服務已經實現了Baggage透傳能力的前提下，可以通過ASMHeaderPropagation流量規則來指定利用Baggage在鏈路上透傳自訂要求標頭。

   1. 使用以下內容，建立propagation.yaml檔案。以下檔案表示利用Baggage中的上下文資訊，在調用鏈路中透傳名為version的要求標頭。

      apiVersion: istio.alibabacloud.com/v1beta1
      kind: ASMHeaderPropagation
      metadata:
        name: version-propagation
      spec:
        headers:
          - version

   2. 通過kubectl串連ASM執行個體，執行以下命令， 建立ASMHeaderPropagation流量規則。

      kuebctl apply -f propagation.yaml

3. 建立VirtualService流量規則。

   1. 使用以下內容，建立vs-mock.yaml檔案。

      展開查看YAML內容

      apiVersion: networking.istio.io/v1beta1
      kind: VirtualService
      metadata:
        name: vs-mock-default-mocka
      spec:
        hosts:
          - mocka.default.svc.cluster.local
        http:
          - match:
              - headers:
                  version:
                    exact: v1
            route:
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v1
                fallback:
                  target:
                    host: mocka.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v2
            route:
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v2
                fallback:
                  target:
                    host: mocka.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v3
            route:
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v3
                fallback:
                  target:
                    host: mocka.default.svc.cluster.local
                    subset: v1
      ---
      apiVersion: networking.istio.io/v1beta1
      kind: VirtualService
      metadata:
        name: vs-mock-default-mockb
      spec:
        hosts:
          - mockb.default.svc.cluster.local
        http:
          - match:
              - headers:
                  version:
                    exact: v1
            route:
              - destination:
                  host: mockb.default.svc.cluster.local
                  subset: v1
                fallback:
                  target:
                    host: mockb.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v2
            route:
              - destination:
                  host: mockb.default.svc.cluster.local
                  subset: v2
                fallback:
                  target:
                    host: mockb.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v3
            route:
              - destination:
                  host: mockb.default.svc.cluster.local
                  subset: v3
                fallback:
                  target:
                    host: mockb.default.svc.cluster.local
                    subset: v1
      ---
      apiVersion: networking.istio.io/v1beta1
      kind: VirtualService
      metadata:
        name: vs-mock-default-mockc
      spec:
        hosts:
          - mockc.default.svc.cluster.local
        http:
          - match:
              - headers:
                  version:
                    exact: v1
            route:
              - destination:
                  host: mockc.default.svc.cluster.local
                  subset: v1
                fallback:
                  target:
                    host: mockc.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v2
            route:
              - destination:
                  host: mockc.default.svc.cluster.local
                  subset: v2
                fallback:
                  target:
                    host: mockc.default.svc.cluster.local
                    subset: v1
          - match:
              - headers:
                  version:
                    exact: v3
            route:
              - destination:
                  host: mockc.default.svc.cluster.local
                  subset: v3
                fallback:
                  target:
                    host: mockc.default.svc.cluster.local
                    subset: v1
      

      此檔案為mocka→mockb→mockc的服務調用鏈路建立流量泳道路由規則。具體來說，是通過匹配調用鏈路中透傳的version要求標頭內容、將請求轉寄到對應的版本（例如，帶有version: v2要求標頭的請求都發送到v2版本的服務）。同時，該流量規則也指定了流量回退規則：當調用鏈路中的某個服務的對應版本不存在時，統一將請求回退到服務的v1版本。

   2. 通過kubectl串連ASM執行個體，執行以下命令，建立VirtualService流量規則。

      kubectl apply -f vs-mock.yaml

4. 建立網關引流規則。

   1. 使用以下內容，建立gw-mock.yaml檔案。

      展開查看YAML內容

      apiVersion: networking.istio.io/v1beta1
      kind: Gateway
      metadata:
        name: mockgw
        namespace: default
      spec:
        selector:
          istio: ingressgateway
        servers:
          - hosts:
              - '*'
            port:
              name: http
              number: 80
              protocol: HTTP
      ---
      apiVersion: networking.istio.io/v1beta1
      kind: VirtualService
      metadata:
        name: swimlane-ingress-vs-weighted-mock
        namespace: default
      spec:
        gateways:
          - default/mockgw
        hosts:
          - '*'
        http:
          - name: mock-weighted
            route:
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v1
                headers:
                  request:
                    set:
                      version: v1
                weight: 40
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v2
                headers:
                  request:
                    set:
                      version: v2
                weight: 30
              - destination:
                  host: mocka.default.svc.cluster.local
                  subset: v3
                headers:
                  request:
                    set:
                      version: v3
                weight: 30

      此檔案表示為mocka→mockb→mockc的服務調用鏈路建立網關引流規則。引流方式則為權重引流，對於發送到ASM網關的流量，以4:3:3的比例分別轉寄到mocka服務的v1、v2、v3版本。當網關向mocka服務轉寄請求時，會根據轉寄的目標版本為請求添加version要求標頭，保證調用鏈路中存在泳道對應的版本資訊。

   2. 通過kubectl串連ASM執行個體，執行以下命令，建立網關引流規則。

      kubectl apply -f gw-mock.yaml

步驟四：驗證流量泳道是否生效

1. 擷取ASM網關的公網IP。具體操作，請參見步驟二：擷取ASM網關地址。

2. 執行以下命令，設定環境變數。xxx.xxx.xxx.xxx為上一步擷取的IP。

   export ASM_GATEWAY_IP=xxx.xxx.xxx.xxx

3. 驗證全灰階鏈路功能是否生效。

   1. 執行以下命令，查看v1泳道的訪問效果。

      for i in {1..100};  do curl http://${ASM_GATEWAY_IP} ;  echo ''; sleep 1; done;

      預期輸出：

      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v2, ip: 192.168.1.28)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v2, ip: 192.168.1.1)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v1, ip: 192.168.1.27)-> mockb(version: v1, ip: 192.168.1.30)-> mockc(version: v1, ip: 192.168.1.14)
      -> mocka(version: v3, ip: 192.168.1.26)-> mockb(version: v3, ip: 192.168.1.29)-> mockc(version: v1, ip: 192.168.1.14)

      可以看到，流量將以約4:3:3的比例發送到服務調用鏈路的v1、v2、v3三個版本，並由v1作為基準版本，當調用鏈路中不存在某個服務的特定版本時，將會調用該服務的v1版本。