HTTP请求重试条件

  • 重试条件(同x-envoy-retry-on标头)
  • 5xx:上游主机返回5xx响应码,或者根本未予响应(断开/重置/读取超时)
  • gateway-error:网关错误,类似于5xx策略,但仅为502、503或504的应用进行重试
  • connection-failure:在TCP级别与上游服务建立连接失败时进行重试
  • retriable-4xx:上游服务器返回可重复的4xx响应码时进行重试
  • refused-stream:上游服器务使用REFUSED——STREAM错误码重置时进行重试
  • retriable-status-codes:上游服务器的响应码与重试策略或x-envoy-retriable-status-codes标头值中定义的响应码匹配时进行重试
  • reset:上游主机完全不响应时(disconnect/reset/read超时),Envoy将进行重试;
  • retriable-headers:如果上游服务器响应报文匹配重试策略或 x-envoy-retriable-header-names标头中包含的任何标头,则Envoy将尝试重试
  • envoy-ratelimited:标头中存在x-envoy-ratelimited时进行重试
  • 重试条件2(同x-envoy-retry-grpc-on标头)
  • cancelled:gRPC应答标头中的状态码是“cancelled”时进行重试
  • deadline-exceeded:gRPC应答标头中的状态码是“deadline-exceeded”时进行重试
  • internal:gRPC应答标头中的状态码是“internal”时进行重试
  • resource-exhausted:gRPC应答标头中的状态码是“resource-exhausted”时进行重试
  • unavailable:gRPC应答标头中的状态码是“unavailable”时进行重试
  • 默认情况下,Envoy不会进行任何类型的重试操作,除非明确定义

virtualservice-proxy.yaml

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
name: proxy
spec:
hosts:
- "app.wgs.com" # 对应于gateways/proxy-gateway
- "proxy"
- "proxy.default.svc"
gateways:
- istio-system/proxy-gateway # 相关定义仅应用于Ingress Gateway上
#- mesh
http:
- name: default
route:
- destination:
host: proxy
timeout: 1s
retries:
attempts: 5
perTryTimeout: 1s
retryOn: 5xx,connect-failure,refused-stream

virtualservice-demoapp.yaml

apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
name: demoapp
spec:
hosts:
- demoapp
http:
- name: canary
match:
- uri:
prefix: /canary
rewrite:
uri: /
route:
- destination:
host: demoapp
subset: v11
fault:
abort:
percentage:
value: 50
httpStatus: 555
- name: default
route:
- destination:
host: demoapp
subset: v10
fault:
delay:
percentage:
value: 50
fixedDelay: 3s

更新demoapp svc

# kubectl apply -f virtualservice-demoapp.yaml -f virtualservice-proxy.yaml 
virtualservice.networking.istio.io/demoapp configured
virtualservice.networking.istio.io/proxy configured

访问demoapp

测试超时

 upstream request timeout

~# while true;do curl app.wgs.com;sleep 0.5;done
upstream request timeoutProxying value: iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!
- Took 5 milliseconds.
Proxying value: iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!
- Took 5 milliseconds.
upstream request timeoutupstream request timeoutupstream request timeoutProxying value: iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!
- Took 4 milliseconds.
upstream request timeoutProxying value: iKubernetes demoapp v1.0 !! ClientIP: 127.0.0.6, ServerName: demoappv10-78b6586d58-kdv4m, ServerIP: 172.20.154.195!
- Took 4 milliseconds.

istio部署demoapp应用 (九)HTTP Retry_服务器

测试中断

~# while true;do curl app.wgs.com/canary;sleep 0.5;done
Proxying value: fault filter abort - Took 2 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 4 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 4 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 5 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 4 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 5 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-sn9qp, ServerIP: 172.20.154.253!
- Took 3 milliseconds.
Proxying value: fault filter abort - Took 4 milliseconds.
Proxying value: fault filter abort - Took 2 milliseconds.
Proxying value: fault filter abort - Took 2 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 4 milliseconds.
Proxying value: fault filter abort - Took 2 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-hckjf, ServerIP: 172.20.89.189!
- Took 4 milliseconds.
Proxying value: iKubernetes demoapp v1.1 !! ClientIP: 127.0.0.6, ServerName: demoappv11-78bf898c74-sn9qp, ServerIP: 172.20.154.253!
- Took 4 milliseconds.

istio部署demoapp应用 (九)HTTP Retry_状态码_02

参考文档

​https://istio.io/latest/zh/docs/reference/config/networking/virtual-service/#HTTPRetry​