I'm in the process of upgrading a (very) old stack. Now at version 6.8.12, I want to implement security.
The issue is : it's a live, production system. It's ingesting 2.6K e/s and altough I have a little bit of spooling (through redis), it is not unlimited. It is also not-minimal, with 6 data nodes and 2 ingest/display nodes.
How can I enable inter-node encryption and TLS security with minimal downtime and without losing any event data ?
(note : I have read the documentation at https://www.elastic.co/blog/getting-started-with-elasticsearch-security and others and I think I have a pretty good understanding of the process - but most examples are for either small or idle clusters where mine is neither small nor idle)