Do I need to backup cluster global metadata?

If yes, then how?

I'm thinking about scenario where all my master nodes are lost. I did some tests here to check what happens when masters are lost; and I see that ES can recover from whatever is left on data nodes pretty well.

I wonder if it would help to restore masters from a backup in such case. If yes, then, again, how to properly create such backup?


Use snapshot and restore -

Yes, but that talks about snapshots of indices. I'm interested in backing up the metadata only. My scenario is that masters (and only masters) die, i.e. I do not need to restore data nodes at all.