Istio 熔断策略及envoy配置

设置如下策略熔断策略

apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  creationTimestamp: "2020-06-22T03:11:20Z"
  generation: 4
  name: productpage
  namespace: istio-bookinfo
spec:
  host: productpage
  subsets:
  - labels:
      version: v1
    name: v1
  trafficPolicy:
    connectionPool:
      http:
        http1MaxPendingRequests: 1
        maxRequestsPerConnection: 1
      tcp:
        maxConnections: 1
    outlierDetection:
      baseEjectionTime: 3m
      consecutiveErrors: 1
      interval: 1s
      maxEjectionPercent: 100

测试结果显示大约38%左右被熔断

$ siege -c 3 -b http://istiobookinfo.lab.f5se.io/productpage
^C
{	"transactions":			          98,
	"availability":			       38.13,
	"elapsed_time":			       25.20,
	"data_transferred":		        4.98,
	"response_time":		        0.76,
	"transaction_rate":		        3.89,
	"throughput":			        0.20,
	"concurrency":			        2.97,
	"successful_transactions":	          98,
	"failed_transactions":		         159,
	"longest_transaction":		        6.17,
	"shortest_transaction":		        0.01
}

envoy上的配置，熔断是在cluster里

{
"version_info": "2020-06-23T02:35:43Z/123",
"cluster": {
"@type": "type.googleapis.com/envoy.api.v2.Cluster",
"name": "outbound|9080||productpage.istio-bookinfo.svc.cluster.local",
"type": "EDS",
"eds_cluster_config": {
"eds_config": {
"ads": {}
},
"service_name": "outbound|9080||productpage.istio-bookinfo.svc.cluster.local"
},
"connect_timeout": "10s",
"max_requests_per_connection": 1,
"circuit_breakers": {
"thresholds": [
{
"max_connections": 1,
"max_pending_requests": 1,
"max_requests": 4294967295,
"max_retries": 4294967295
}
]
},
"outlier_detection": {
"interval": "1s",
"base_ejection_time": "180s",
"max_ejection_percent": 100,
"enforcing_consecutive_5xx": 0,
"consecutive_gateway_failure": 1,
"enforcing_consecutive_gateway_failure": 100
},