Update rate limits at runtime in WebApiThrottle is not working

Question

I have a WebApi in ASP.NET MVC and I need to control the limit of access and besides that I need to change the values of the limits at run time. I implemented like this example on this site WebApiThrottle (section Update rate limits at runtime )

That's the code in my WebApiConfig:

//trace provider
var traceWriter = new SystemDiagnosticsTraceWriter()
{
    IsVerbose = true
};
config.Services.Replace(typeof(ITraceWriter), traceWriter);
config.EnableSystemDiagnosticsTracing();

//Web API throttling handler
config.MessageHandlers.Add(new ThrottlingHandler(
    policy: new ThrottlePolicy(perMinute: 3, perHour: 30, perDay: 35, perWeek: 3000)
    {
        //scope to IPs
        IpThrottling = true,
        //scope to clients
        ClientThrottling = true,
        ClientRules = new Dictionary<string, RateLimits>
        {
            { "client-key-1", new RateLimits { PerMinute = 1, PerHour = 60 } }
        },

        //scope to endpoints
        EndpointThrottling = true
    },

    //replace with PolicyMemoryCacheRepository for Owin self-host
    policyRepository: new PolicyCacheRepository(),

    //replace with MemoryCacheRepository for Owin self-host
    repository: new CacheRepository(),

    logger: new TracingThrottleLogger(traceWriter)));

I'm defining three requests per minute like default and one request per minute to the client with key "client-key-1". But when I test using PostMan (I'm passing the Authorization token with the value client-key-1), I noticed that only the default configuration is being used, because only after three requests I got the message:

And, even if I update the rate limit, using the function:

public void UpdateRateLimits()
{
    //init policy repo
    var policyRepository = new PolicyCacheRepository();

    //get policy object from cache
    var policy = policyRepository.FirstOrDefault(ThrottleManager.GetPolicyKey());

    //update client rate limits
    policy.ClientRules["client-key-1"] =
        new RateLimits { PerMinute = 20 };

    //apply policy updates
    ThrottleManager.UpdatePolicy(policy, policyRepository);

}

The message "API calls quota exceeded! maximum admitted 3 per Minute." continues showing up.

Did anyone have this problem?

Answer 1

After try a lot of things I could configure my class to consider my custom rate limits.

What I did was:

1) I created a class to override the method SetIdentity like in the site WebApiThrottle :

public class CustomThrottlingHandler : ThrottlingHandler
{
    public CustomThrottlingHandler(ThrottlePolicy policy, IPolicyRepository policyRepository, IThrottleRepository repository, IThrottleLogger logger, IIpAddressParser ipAddressParser = null)
        : base(policy, policyRepository, repository, logger, ipAddressParser)
    {

    }

    protected override RequestIdentity SetIdentity(HttpRequestMessage request)
    {
        return new RequestIdentity
        {
            ClientKey = request.Headers.Contains("my-header") ? request.Headers.GetValues("my-header").First() : "anon",
            ClientIp = base.GetClientIp(request).ToString(),
            Endpoint = request.RequestUri.AbsolutePath.ToLowerInvariant()
        };
    }
}

2) I changed the MessageHandlers.Add to use my custom class (CustomThrottlingHandler) instead of the class ThrottlingHandler:

public static void Register(HttpConfiguration config)
{
    //trace provider
    var traceWriter = new SystemDiagnosticsTraceWriter()
    {
        IsVerbose = true
    };
    config.Services.Replace(typeof(ITraceWriter), traceWriter);
    config.EnableSystemDiagnosticsTracing();

    //Web API throttling handler
    config.MessageHandlers.Add(new CustomThrottlingHandler(
        policy: new ThrottlePolicy(perMinute: 20, perHour: 30, perDay: 35, perWeek: 3000)
        {
            //scope to IPs
            IpThrottling = true,

            //scope to clients
            ClientThrottling = true,
            ClientRules = new Dictionary<string, RateLimits>
            { 
                { "api-client-key-1", new RateLimits { PerMinute = 60, PerHour = 600 } },
                { "api-client-key-2", new RateLimits { PerDay = 5000 } }
            },

            //scope to endpoints
            EndpointThrottling = true
        },

        //replace with PolicyMemoryCacheRepository for Owin self-host
        policyRepository: new PolicyCacheRepository(),

        //replace with MemoryCacheRepository for Owin self-host
        repository: new CacheRepository(),

        logger: new TracingThrottleLogger(traceWriter)));
}