You can update an existing lifecycle policy to fix mistakes or change strategies for newly created indices. It is possible to update policy definitions and an index’s index.lifecycle.name settings independently. To prevent the situation that phase definitions are modified while currently being executed on an index, each index will keep the version of the current phase definition it began execution with until it completes. This also means that changes to min_age will not be propagated. If a new policy is set that introduces a later min_age for the currently executing phase, that new min_age will not be picked up by the update.

There are three scenarios for examining the behavior updating policies and their effects on policy execution on indices.