We completed an upgrade from Elasticsearch 5.x to 6.8 this month. It wasn’t seamless, but a few things helped.
Gotchas we hit:
-
_type deprecation: We had to refactor many mappings to use a single type per index
- Mapping conflicts: dynamic mapping rules changed subtly in v6
- Deprecations in query DSL: especially around filtered queriesTools that helped:
-
elasticsearch-migration plugin
- Snapshot/restore for index backups
- Integration tests against test clustersFinal result: smoother queries, reduced cluster memory pressure, and better Kibana dashboards.