Alibaba Cloud Service Mesh:Referência do CRD ASMCircuitBreaker

apiVersion: istio.alibabacloud.com/v1       # v1beta1 for ASM < 1.15.3.105
kind: ASMCircuitBreaker
metadata:
  name: <circuit-breaker-name>
spec:
  workloadSelector:                          # Required. Labels to select target pods/VMs.
    labels:
      <label-key>: <label-value>
  isGateway: false                           # Whether this applies to a gateway.
  applyToTraffic: sidecar_outbound           # ASM 1.25+. Traffic direction.
  configs:                                   # Required. One or more circuit breaking rules.
    - name: <config-name>
      target_services:                       # ASM 1.25+. Services to protect.
        - kind: Service                      # Service | ServiceEntry | VirtualService
          namespace: <namespace>
          name: <service-name>
          port: <port-number>
          section_name: <route-name>         # VirtualService only.
      match:                                 # Route-level match conditions.
        vhost:
          name: <virtual-host-name>
          port: <port>
          route:
            name_match: <route-name>
            header_match:                    # ASM 1.16+.
              - name: <header-name>
                exact_match: <value>         # Choose one match type.
                regex_match: <pattern>
                prefix_match: <prefix>
                suffix_match: <suffix>
                present_match: true
                invert_match: false
      breaker_config:                        # Circuit breaking thresholds.
        window_size: 10s                     # Statistics time window (max 12s).
        break_duration: 30s                  # How long the circuit stays open.
        slow_request_rt: <duration>          # Slow request latency threshold.
        average_request_rt: <duration>       # Average response time.
        max_slow_requests: <count>           # Max slow requests before tripping.
        error_percent:                       # 5xx error percentage threshold.
          value: <0-100>
        gateway_error_percent:               # 502/503/504 error threshold. ASM 1.24.6.54+.
          value: <0-100>
        min_request_amount: 0                # Min requests before evaluating error_percent.
        custom_response:                     # Response returned when circuit is open.
          status_code: <http-status-code>
          header_to_add:
            <header-name>: <header-value>
          body: <response-body>

applyToTraffic

Valores válidos:

ASMCircuitBreakerSpec

CircuitBreakerConfig

TargetServiceRef

target_services:
- kind: Service
  namespace: default
  name: httpbin
  port: 8000

apiVersion: networking.istio.io/v1
kind: ServiceEntry
metadata:
  name: se-httpbin-external
spec:
  hosts:
  - httpbin.test.com
  location: MESH_EXTERNAL
  ports:
  - name: http
    number: 80
    protocol: HTTP
  - name: https
    number: 443
    protocol: HTTPS
  resolution: DNS

target_services:
- kind: ServiceEntry
  namespace: default
  name: se-httpbin-external
  port: 80

apiVersion: networking.istio.io/v1
kind: VirtualService
metadata:
  name: vs-httpbin
spec:
  hosts:
  - httpbin.test.com
  http:
  - name: default
    route:
    - destination:
        host: httpbin
        port:
          number: 8000

target_services:
- kind: VirtualService
  namespace: default
  name: vs-httpbin
  section_name: default

BreakerConfig

Os limiares de circuit breaking dividem-se em duas categorias:

• Detecção de requisições lentas: Os campos slow_request_rt, max_slow_requests e average_request_rt definem quando ocorre a abertura do circuito baseada em latência.

• Detecção de taxa de erros: Os campos error_percent e gateway_error_percent determinam quando a abertura do circuito ocorre devido a erros.

Ambas as categorias compartilham os campos window_size, break_duration e min_request_amount.

CustomResponse

Define a resposta retornada aos clientes quando o circuit breaker rejeita uma requisição.

CircuitBreakerMatch

VirtualHostMatch

RouteMatch

HeaderMatcher

Especifique exatamente um tipo de correspondência por entrada (regex_match, exact_match, prefix_match, suffix_match ou present_match).

Circuit breaking no lado do cliente

Esta configuração aplica-se ao tráfego de saída da aplicação sleep para httpbin na porta 8000. O circuit breaker é acionado quando qualquer uma das condições abaixo é atendida dentro de uma janela de 10 segundos:

• Mais de 60% das requisições retornam erros 5xx.

• Mais de 10 requisições excedem o limiar de tempo de resposta de 100 ms.

Quando o circuit breaker está aberto, os clientes recebem um código de status 499 com um corpo de resposta e um header personalizados.

apiVersion: istio.alibabacloud.com/v1
kind: ASMCircuitBreaker
metadata:
  name: client-break
spec:
  workloadSelector:
    labels:
      app: sleep
  applyToTraffic: sidecar_outbound
  configs:
    - target_services:
      - name: httpbin
        port: 8000
      breaker_config:
        slow_request_rt: 0.1s
        break_duration: 90s
        window_size: 10s
        max_slow_requests: 10
        min_request_amount: 3
        error_percent:
          value: 60
        custom_response:
          header_to_add:
            x-envoy-circuitbreak: "true"
          body: "hello, break!"
          status_code: 499

Circuit breaking no Waypoint

Esta configuração aplica os mesmos limiares de circuit breaking por meio de um proxy waypoint chamado default:

apiVersion: istio.alibabacloud.com/v1
kind: ASMCircuitBreaker
metadata:
  name: test
spec:
  workloadSelector:
    labels:
      gateway.networking.k8s.io/gateway-name: default
  applyToTraffic: waypoint
  configs:
    - target_services:
      - name: httpbin
        port: 8000
      breaker_config:
        slow_request_rt: 0.1s
        break_duration: 90s
        window_size: 10s
        max_slow_requests: 10
        min_request_amount: 3
        error_percent:
          value: 60
        custom_response:
          header_to_add:
            x-envoy-circuitbreak: "true"
          body: "hello, break!"
          status_code: 499