I just did a test upgrade from elastic 7.17.11 to 8.8.2 and was able to use my old indices and write to them without reindexing to a new index. The only information I found was upgrading from 5.x or 6.x to 8 - but nothing is stating required steps to upgrade from 7.17.x to 8.x.
Is reindexing no more required? What happens when upgrading to some future 9.x? Will I have to reindex
- before going to 9
- after going to 9
- or not at all?