Circuit breaker

Introduction

Circuit breaker help to isolate upstream services during runtime, all of invocation will be executed by circuit, under its protection, if there is too much error, time out or concurrency, circuit will open to stop network communication it also monitor each service call to make service observable

Configuration

Configuration Format as below：

cse.{namespace}.Consumer.{serviceName}.{property} explanation:

{namespace}：it can be isolation|circuitBreaker|fallback|fallbackpolicy.

{serviceName}: it is optional. it is the service level configuration, it represent the target service name

{property}: configuration items

cse.isolation.timeoutInMilliseconds

(optional, int) if delay for a time, this call will be considered as failure, default is 30000

cse.isolation.maxConcurrentRequests

(optional, int) max concurrency, default is 1000

cse.circuitBreaker.scope

(optional, string) service or api, default is api, go chassis create a dedicated circuit for every api, invocation will be isolated based on api if set to service, all of API for each service share one circuit, it will isolate the service.

cse.circuitBreaker.enabled

(optional, bool) enable circuit breaker or not, default is false

cse.circuitBreaker.forceOpen

(optional, bool) if it is true, will forcely open the circuit, default is false

cse.circuitBreaker.forceClosed

(optional, bool) ignore all configurations forcely close crcuit all the time, default is false

cse.circuitBreaker.sleepWindowInMilliseconds

(optional, int) after a circuit open, how long it should wait for next retry, if retry failed, circuit will open again. default is 15000

cse.circuitBreaker.requestVolumeThreshold

(optional, int) it means in 10 seconds after how many request fails, circuit breaker should open default is 20

cse.circuitBreaker.errorThresholdPercentage

(optional, int) it means how many err percentage met, circuit breaker should open, default is 50

cse.fallback.enabled

(optional, bool) enable fallback or not, default is true

cse.fallbackpolicy.policy

(optional, string) fallback policy [returnnull| throwexception]，default is returnnull

examples

cse:
  isolation:
    Consumer:
      timeoutInMilliseconds: 1
      maxConcurrentRequests: 100
      ServerA: # service level config
        timeoutInMilliseconds: 1000
        maxConcurrentRequests: 1000
  circuitBreaker:
    scope: api
    Consumer:
      enabled: false
      forceOpen: false
      forceClosed: true
      sleepWindowInMilliseconds: 10000
      requestVolumeThreshold: 20
      errorThresholdPercentage: 10
      ServerB: # service level config
        enabled: true
        forceOpen: false
        forceClosed: false
        sleepWindowInMilliseconds: 10000
        requestVolumeThreshold: 20
        errorThresholdPercentage: 5
  fallback:
    Consumer:
      enabled: true
      maxConcurrentRequests: 20
  fallbackpolicy:
    Consumer:
      policy: throwexception

you must set bizkeeper-consumer handler in chain before load balancing and transport here is a example

handler:
  chain:
    Consumer:
      default: bizkeeper-consumer, router, loadbalance, ratelimiter-consumer,transport