public class ThrottlePlugin : IPlugin
{
    /// <param name="redisHost">host name</param>
    /// <param name="redisPort">port</param>
    /// <param name="redisPassword">password</param>
    public ThrottlePlugin(string redisHost, int redisPort, string redisPassword = null)
    {
        _redisClient = new RedisClient(redisHost, redisPort, redisPassword);
    }

    private string _scriptSha;
    private RedisClient _redisClient;
    private Dictionary<Type, ThrottleInfoAttribute> _throttleInfoMap = new Dictionary<Type, ThrottleInfoAttribute>();

    public void Register(IAppHost appHost)
    {
        RegisterThrottleInfoForAllRoutes(appHost);

        //Store the lua script in redis for quick ref during request lookups
        _redisClient.RemoveAllLuaScripts();
        _scriptSha = _redisClient.LoadLuaScript(ReadLuaScriptResource("rate_limit.lua"));

        appHost.GlobalRequestFilters.Add((request, response, requestDto) =>
        {
            //this request isn't setup to be throttled
            if (!_throttleInfoMap.ContainsKey(requestDto.GetType()))
                return;

            var throttleInfo = _throttleInfoMap[requestDto.GetType()];
            var key = string.Format("{0}:{1}", request.RemoteIp, request.OperationName);

            try
            {
                var result = _redisClient.ExecLuaShaAsString(_scriptSha,
                    new[] {key},
                    new[]
                    {
                        throttleInfo.PerMinute.ToString(),
                        throttleInfo.PerHour.ToString(),
                        throttleInfo.PerDay.ToString(),
                        SecondsFromUnixTime().ToString()
                    }
                    );
                if (result != null)
                {
                    response.StatusCode = 429;
                    response.StatusDescription = "Too many Requests. Back-off and try again later.";
                    response.Close();
                }
            }
            catch (Exception ex)
            {
                //got an error calling redis so log something and let the redis through
            }
        });
    }

    private void RegisterThrottleInfoForAllRoutes(IAppHost appHost)
    {
        //pre calculate all request throttling attributes to reduce lookup time during a request
        foreach (var operation in appHost.Metadata.Operations)
        {
            var throttleAttribute = operation.RequestType.GetCustomAttributes(typeof(ThrottleInfoAttribute)).First() as ThrottleInfoAttribute;
            if (throttleAttribute == null)
                continue;

            _throttleInfoMap.Add(operation.RequestType, throttleAttribute);
        }
    }

    private int SecondsFromUnixTime()
    {
        TimeSpan t = (DateTime.UtcNow - new DateTime(1970, 1, 1));
        return (int)t.TotalSeconds;
    }

    private string ReadLuaScriptResource(string resourceName)
    {
        var assembly = Assembly.GetExecutingAssembly();
        var script = string.Empty;

        using (Stream stream = assembly.GetManifestResourceStream("Throttling." + resourceName))
        using (StreamReader reader = new StreamReader(stream))
        {
            script = reader.ReadToEnd();
        }

        return script;
    }
}