High Memory Pressure due to a GC change in JDK 21

This version of Elasticsearch is bundled with JDK 21. In JDK 21 Preventive GC has been removed. This may lead to increased memory pressure and an increased number of CircuitBreakerExceptions when retrieving large documents under some particular load. (issue: #99592)

If you needed to explicitly enable Preventive GC for your workload in a previous Elasticsearch version, we recommend you avoid to upgrade to this version, as the settings to enable Preventive GC have been removed from JDK 21.