Migrating to Java 27: A Guide to GC, Flags, and Container Memory

Upgrading to JDK 27 can significantly alter the behavior of Java applications, even without changes to the source code. This article explores key changes in the JVM runtime, specifically focusing on garbage collector (GC) selection, memory management strategies, and the handling of deprecated startup flags. The author details how modern Java versions adapt to containerized environments and provides practical recommendations for preparing services for migration. Special attention is given to potential risks associated with changes in system resource management. The article serves as a guide for developers and DevOps engineers aiming to ensure the stability and performance of their applications after platform updates. Readers are provided with a checklist for infrastructure readiness and tips on optimizing startup parameters to achieve maximum efficiency under new conditions.