CoreMedia configures the Parallel GC (-XX:+UseParallelGC) as the default garbage collector for all containerized Spring Boot applications. This is expressed via the JAVA_PARALLEL_GC=true environment variable that the java-application-base image entrypoint evaluates at startup.

This default was introduced as a deliberate workaround for a JDK bug that causes G1GC to fail with an OutOfMemoryError under specific memory allocation patterns. The bug affects all JDK versions prior to JDK 25 and will not be backported to earlier release trains.

Why delivery components are primarily affected: The image transformation pipeline allocates large, contiguous heap regions whose size depends on the source image resolution and the requested transformation operations. Part of the transformation is executed via JNI (native image-processing libraries). While a JNI call is active, G1GC cannot free that memory region — if heap pressure is high enough at that moment, the JVM raises an OutOfMemoryError. Parallel GC does not have this limitation and is therefore the safer default.