The Throttling Suite provides throttling control capabilities to the ASP.NET applications. It is highly customizable; including "log-only" mode.
The library contains multiple controller types implementing different throttling strategies:
- Linear throttling - limits the number of calls by enforcing specified delay between consequent requests;
- Short Average - limits the number of calls by specified number of requests per configured duration; it does not limit overall number of requests, but rather assures blocking excessive requests; this strategy is very helpful to cut the requests flooding caused by such user behaviors as multi-click or hard click on F5 button;
- Long Average - limits the number of calls by specified number of requests per configured duration; this strategy limits an overall number of calls within long time duration; this is also known as applying penalty to the client for excessive application use.
Each throttling controller uniquely determines the client making requests. It does not purely rely on client IP address allowing multiple clients from the same network concurrently making requests to the IIS.
The Throttling Suite allows setting multiple controllers within the application and applying each to a pre-filtered traffic. The filters are also configurable.
The Throttling Suite provides two modes: real blocking mode when request is blocked with 429 HTTP Status code and log-only mode whether it logs blocking information to IIS log, but allows request to continue. The log-only mode is very useful when there is a need to determine the most appropriate throttling configuration parameters.
The code is highly optimized having very low memory impact and taking less than 0.3 ms to run on a regular development laptop.
As an extra functionality it provides with real-time snapshot of current throttling status for all controllers. The snap-shot is available online as a JSON output. It requires configuration to assure authorized used as desired by an application.
This component is also available as NuGet Package; search for "ThrottlingSuite" in NuGet Package Manager.