I have Magento CE 2.4.6 running on a Ubuntu server with Elasticsearch 8.11.4. For a mandatory module I absolutely need, I need to downgrade to ES 7.9.3.
I read everywhere it was not possible to downgrade ES. Is there a way to uninstall ES 8.4.11 and install ES 7.9.3 without damaging the system? If yes, how?
(I don't want to make any mistakes)
The upgrade from 7.x to 8.x creates changes in indices and configurations that are not easy revesible. Suggestion: build a test 7.x cluster and add the snapshot repositroy from 8.x as READ-ONLY. Import your indices one by one and test to see if you can still use them or what changes are necessary so you can revert them to 7.x . Once you tested all of them and you know it is doable, make a prod cluster and migrate all closed indices . Then test your integrations and plan a rupture day. You can migrate services one by one to minimize data loss or make a planed downtime . You also need to read all the breaking changes inbetween your versions