Version 9.0.4 of the Elastic Stack has been released, offering various performance and stability enhancements compared to its predecessor, version 9.0.3. Notably, Logstash's persistent queue now achieves significantly higher throughput when its workers are caught up, thanks to the elimination of lock contention in pipeline workers, giving queue writers priority when batches are not yet full. Pipelines optimized with larger batch sizes are expected to see even greater improvements in performance. Users are encouraged to refer to the release notes for a detailed list of fixed issues and changes in this version.