Istio断路器

Istio提供熔断的功能来使你的微服务具有应对故障、潜在峰值和其他网络因素影响的能力。比如熔断器可以允许你限制服务并发连接的次数、调用失败的次数，一旦达到限制的次数，流量就会被Envoy拦截。

部署Deployment资源

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  selector:
    app: nginx
  ports:
    - port: 80
      targetPort: 80

定义DestinationRule

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: nginx-dr
spec:
  host: nginx
  trafficPolicy:
    connectionPool:
      http:
        http1MaxPendingRequests: 1
        maxRequestsPerConnection: 1
      tcp:
        maxConnections: 1
    outlierDetection:
      consecutiveErrors: 1
      intercal: 10s
      baseEjectionTime: 10s
      masEjectionPercent: 100

使用fortio测试

安装fortio

curl -L https://github.com/fortio/fortio/releases/download/v1.3.1/fortio-1.3.1-1.x86_64.rpm -o fortio-1.3.1-1.x86_64.rpm

rpm -ivh fortio-1.3.1-1.x86_64.rpm

测试

# -c表示并发数 -n表示总请求数 -qps表示每秒查询数，0表示不限制 地址是svc的CLUSTER-IP
fortio load -c 3 -n 30 -qps 0 http://10.1.248.193

可以从下图看出只有33%的请求成功了