i run 36 websites which have thousands of pages thge site is configured to cache on access using standard in-memory caching ASP.NET 4.6 after some digging into IIS logd i am using an SEO bot tool, SEMrush, which essentially triggers a denial of service attack against the sites because of simultaneous requests for the 'long tail' of pages which are never viewed by a user and hence aren't stored in the cache.