TL;DR

Elasticsearch 9.4.3 improves query performance and stability with enhancements to the query cache and fixes a critical bug causing incorrect results with range queries.

Fixes Worth Knowing

• Range queries now return correct results, addressing a bug introduced in 9.3.0.
• Query cache performance is improved, reducing latency for repeated searches.
• Fixed an issue where cluster restarts could lead to temporary search unavailability.

TL;DR

Elasticsearch now supports persistent enrichment, allowing you to add data to documents in real-time using external sources (like databases or APIs) without impacting search performance.

New

• Persistent Enrichment: Add data to documents on ingest using external sources.
• Scripted Fields: Support for painless scripting in runtime fields.

Fixes Worth Knowing

• Fixed a bug causing incorrect results when using range queries with date histograms.
• Resolved an issue where cluster health checks could intermittently fail.

TL;DR

Elasticsearch now supports wildcard characters in index names when using the Delete By Query API, improving flexibility for data management.

Fixes Worth Knowing

• Delete By Query API now correctly handles index names containing wildcard characters (special characters representing other values).
• Fixed a potential race condition when reindexing data, preventing rare data loss scenarios.

TL;DR

Elasticsearch 9.0 introduces significant changes to time-based data handling with Data Streams, offering simplified data tiering and retention.

Breaking

• Java 17 is now required. (Programming language)
• The _source field is no longer returned by default. (Data storage format) - Explicitly request it in queries.

New

• Data Streams now support automatic rollover and lifecycle management. (Automated data handling)
• Improved performance for time series data. (Data analysis)

Fixes Worth Knowing

• Fixed a bug causing incorrect results when using range queries on date fields. (Query functionality)

TL;DR

Elasticsearch 8.0 introduces significant changes to time-based data handling with data streams, replacing the old index lifecycle management approach and offering simplified data management.

Breaking

• Index lifecycle policies are removed (automatic index management).
• The _template API is removed (use composable templates).

New

• Data Streams (simplified data ingestion) provide a unified way to write and manage time-based data.
• Composable Templates (index configuration) allow for more flexible and reusable index settings.

Fixes Worth Knowing

• Fixed a bug causing incorrect results when using range queries with date histograms.
• Improved performance of wildcard queries against large text fields.

TL;DR

Elasticsearch 6.8.23 improves security by updating the bundled JDK to address several critical vulnerabilities.

Fixes Worth Knowing

• Resolved a potential issue where high CPU usage could occur during index operations (indexing is adding data).
• Fixed a bug causing incorrect results when using the terms aggregation with large numbers of terms (aggregations summarize data).