NCache provides flexible ways to determine data invalidation using various dependencies. However, you can implement your custom logic for dependency if none of the built in invalidation strategies fulfil your own requirements. For example, you can implement a custom dependency which makes a call to a web service for the validation of data.
In custom dependency, you can implement your custom logic which defines when a certain data becomes invalid. For this purpose, NCache provides an abstract class ExtensibleDependency. All you need to do is to inherit your dependency class from this class and override its HasChanged property.
Once implemented, place the assembly or executable file of class overriding
ExtensibleDependency in NCache service folder and restart the cache.
Like expiration, cache clean up thread periodically
HasChanged() property of custom dependency and if it returns true, the
item is removed from the cache.
For more details on implementation of Custom Cache Dependency, please read Custom Cache Dependency in section Server Side API Programming.