> For the complete documentation index, see [llms.txt](https://docs.umbraco.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.umbraco.com/umbraco-cms/17.latest/extend-your-project/server-side-extensions/cache/icacherefresher.md). # ICacheRefresher *This section describes what ICacheRefresher and ICacheRefresher\ are and how to use them to invalidate your cache correctly including load balanced environments* ## What is an ICacheRefresher This interface has been in the Umbraco core for a significant period. However, it has really only been used to ensure that content cache is refreshed among all server nodes participating in a load balanced scenario. An `ICacheRefresher` is the primary method that invalidates *any* cache needing refreshment or removal. This applies regardless of a load balanced environment. There are now a few different types of `ICacheRefreshers` in the Umbraco core. It is important to understand the differences between them and how cache invalidation works across multiple server nodes. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.umbraco.com/umbraco-cms/17.latest/extend-your-project/server-side-extensions/cache/icacherefresher.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.