lb.snip4.go

proxy.ErrorHandler = func(writer http.ResponseWriter, request *http.Request, e error) {
  log.Printf("[%s] %s\n", serverUrl.Host, e.Error())
  retries := GetRetryFromContext(request)
  if retries < 3 {
    select {
      case <-time.After(10 * time.Millisecond):
        ctx := context.WithValue(request.Context(), Retry, retries+1)
        proxy.ServeHTTP(writer, request.WithContext(ctx))
      }
      return
    }

  // after 3 retries, mark this backend as down
  serverPool.MarkBackendStatus(serverUrl, false)

  // if the same request routing for few attempts with different backends, increase the count
  attempts := GetAttemptsFromContext(request)
  log.Printf("%s(%s) Attempting retry %d\n", request.RemoteAddr, request.URL.Path, attempts)
  ctx := context.WithValue(request.Context(), Attempts, attempts+1)
  lb(writer, request.WithContext(ctx))
}