Understanding Elasticsearch ILM Lifecycle Actions


I want to better understand ILM and the actions it is doing in sequence. For example: What do I have to do if I want to move a hot-index (phase complete) to the next warm-phase and then to cold? I found the ilm-move documentation and this post How force to move to Warm phase - #3 by Anabella_Cristaldi

Is allocate the first step for moving an index to the next phase? And is ILM then doing the rest of steps automatically?

I couldn't find documentation about the sequence ILM is doing. So this would be interesting in case you have to fix something manually.

So for example from hot to warm, where in warm-phase shrink and forcemerge is selected, would the ILM action sequence be:

  • allocate
  • unfollow
  • forcemerge
  • shrink