Description
Description
Changing lifecycle policies or DLM settings on data streams is an operation that easily performed, but it's hard to tell what's going to happen directly after the change is applied:
- Will indices be deleted?
- Will data be moved from one node to another?
This information is crucial for a user to decide whether the change should be performed or not - it's easy to make a change that looks harmless on the surface but will reshuffle most of the data of the cluster.
To help the user making the right decisions, there should be a simulate lifecycle API that acts as a dry run for lifecycle changes - something like "if this policy change is applied, then these actions will be kicked off immediately: ..."
This can be integrated into the management UI to prompt the user via modal if they are in the process of doing expensive changes.