Java Dynamic Heap Size

Below statistics are tested on: amazoncorretto:8-alpine-jre

Percentage values can be used to set Maximum Heap Size:

java -XX:+HeapDumpOnOutOfMemoryError -XX:OnError='echo JVM exited with error' \
  -XX:MaxRAMPercentage=90.0 \
  -XX:MinRAMPercentage=40.0 \
  -XX:+PrintGCDetails -jar app.jar

When using percentage java heap size is set as below,

So, JVM Heap Size doesn’t go beyond 26.67G when using XX:MaxRAMPercentage

Use static value to set Maximum Heap Size when container memory is greater than 32G

java -XX:+HeapDumpOnOutOfMemoryError -XX:OnError='echo JVM exited with error' \
    -Xmx=64G \
    -XX:+PrintGCDetails -jar app.jar