A Saturated Grey

Resilience mechanism in distributed system reduce oversize request available for users.

in this part, we can make resilient using the circuit breaker pattern using a hystrix-golang library.

breakers.go

package breakers

import (
    "github.com/afex/hystrix-go/hystrix"
)

const (
    FetchJson = "fetch.json"
)

func ConfigCircuitBreakers() {
	breakers := make(map[string]hystrix.CommandConfig)

	breakers[FetchJson] = hystrix.CommandConfig{
            Timeout:               1000,
	    MaxConcurrentRequests: 100,
	    ErrorPercentThreshold: 25,
	}

	hystrix.Configure(breakers)
}

main.go

package main

import (
	"github.com/afex/hystrix-go/hystrix"
	"github.com/faizalpribadi/learn/breakers"
	"io/ioutil"
	"log"
	"net/http"
)

func main() {
	breakers.ConfigCircuitBreakers()

	result := make(chan interface{}, 1)

	errChan := hystrix.Go("fetch.json", func() error{
			resp, err := http.Get("https://jsonplaceholder.typicode.com/todos")
			if err != nil {
				return err
			}

			value, err := ioutil.ReadAll(resp.Body)
			if err != nil {
				return err
			}

			result <- string(value)
			return nil

	}, nil)

	select {
    case output := <-result:
        // Do some logic at here
        // or run ur background job processing such as (amazon sqs, or kafka)
		log.Println(output)
	case errResp := <-errChan:
		log.Println(errResp)
	}
}