controller.cs

public async Task SearchProxy()
{
    var timeWindow = DateTime.Now.AddMinutes(-5);
    _failure.RemoveAll(x => x < timeWindow);
    _success.RemoveAll(x => x < timeWindow);
    
    try
    {
        var response = await _httpClient.GetAsync("api/crawler/search" + Request.QueryString,
            new CancellationTokenSource(TimeSpan.FromSeconds(30)).Token);
            
        response.EnsureSuccessStatusCode();
        
        foreach (var header in response.Headers)
            Response.Headers.Add(header.Key, string.Join(",", header.Value));
            
        foreach (var header in response.Content.Headers)
            Response.Headers.Add(header.Key, string.Join(",", header.Value));
            
        await response.Content.CopyToAsync(Response.Body);
        
        _success.Add(DateTime.Now);
    }
    catch
    {
        _failure.Add(DateTime.Now);
        if (_lastRestart < timeWindow && _failure.Count > _success.Count)
        {
            _lastRestart = DateTime.Now;
            Restart();
        }
        throw;
    }
}