Index Lifecycle Management (ILM) is an essential mechanism of Elasticsearch, which has been introduced in Elasticsearch 6.6. It is also known as ILM. ILM establishes a hot-warm-cold architecture, which offers a lifecycle to the index. This lifecycle has four states Hot, Warm, Cold, and Delete state.
An index goes through this lifecycle having different states, first it goes from hot state, then warm and cold and at last from delete state.
Typically, ILM manages the indexes and their operations. Elasticsearch offers the ILM APIs for managing the indexes. Policy Management API, Index Management API, and Operation Management API are the Index Lifecycle Management APIs. These APIs further offers APIs to its user to manage the indexes.
