Enhanced Http Client

Http Client Library that provides "enhanced" http client with resiliency & circuit breaker backed functionality

Retry policy

EnhancedHttpClient will retry requests for

• Network issues
• 5xx HTTP status
• Request Timeout

Circuit breaker policy

Circuit breaker layer resides before retry policy layer and can be in closed|open|half-open states. Used as-is from gobreaker

Usage:

go get github.com/RassulYunussov/ehttpclient

By default ehttpclient.Create produces EnhancedHttpClient with no retry and no circuit breaker. Client can add policies:

• retry
• circuit breaker
• retry + cicruit breaker

Default

No retry policy. No circuit breaker

defaultClient := ehttpclient.Create(200*time.Millisecond)

Retry

The retry policy uses multiplication of attempt & backoffTimeout

// retry count 3
// max delay timeout
// backoff timeout
retryClient := ehttpclient.Create(200*time.Millisecond, ehttpclient.WithRetry(3, 3*100*time.Millisecond, 100*time.Millisecond))

Circuit breaker

// detailed info about configuration can be found here: https://github.com/sony/gobreaker
retryClient := ehttpclient.Create(200*time.Millisecond, ehttpclient.WithCircuitBreaker(1, 2, time.Second, time.Second))

Retry + Circuit breaker

ehttpClient := ehttpclient.Create(200*time.Millisecond, ehttpclient.WithRetry(3, 3*100*time.Millisecond, 100*time.Millisecond), ehttpclient.WithCircuitBreaker(1, 2, time.Second, time.Second))

Make a request

request, err := http.NewRequest(http.MethodGet, "http://localhost:8080", nil)
response, err := client.Do(request)

Notes: care should be taken with "Do" methoud using circuit breaker pattern. It uses resource URI. With high cardinality it may lead to memory exhaustion. Prefer using "DoResourceRequest" with controlled number of resources.