See also Elasticsearch 6.7.0 release notes.
We introduced cross-cluster replication in 6.5.0 as a beta feature, it is now mature enough to declare the feature GA (general availability). Cross-cluster replication enables you to replicate indices that exist in remote clusters to your local cluster. You create an index in your local cluster (known as a follower index) that follows an index (known as a leader index) in a remote cluster. You can also automatically follow indices in a remote cluster that match a pattern. The individual write operations that occur on the leader indices are then replayed on the follower indices. This functionality is useful for replicating data to a second cluster for disaster recovery purposes and for geo-proximity so that reads can be served locally.
Index lifecycle managementedit
We introduced index lifecycle management in 6.6.0 as a beta feature, it is now mature enough to declare the feature GA (general availability). The index lifecycle management feature breaks the lifecycle of an index into four phases: hot, warm, cold, and delete phase. You can define an index lifecycle policy which enables you to:
- Have one primary shard on each hot node to maximize indexing throughput.
- Replace the hot index with a new empty index as soon as the existing index is “full” or after a time period.
- Move the old index to warm nodes, where it can be shrunk to a single shard and force-merged down to a single segment for optimized storage and querying.
- Later, move the index to cold nodes for cheaper storage.
We introduced Elasticsearch SQL in 6.3.0 as an experimental feature, it is now mature enough to declare the feature GA (general availability). This feature enables users who are familiar with SQL to use SQL statements to query Elasticsearch indices. In addition to querying through the SQL API, you can use the Translate API to see how SQL queries are translated to native Elasticsearch queries. There are four methods to access Elasticsearch SQL: through the REST endpoints, the SQL command line interface, the JDBC driver, and the ODBC driver.
For more information, see SQL Access.