Xms/Xmx bound the heap where your objects live and GC runs. Metaspace (post-Java 8, replacing PermGen) grows with loaded classes and lives in native memory. Container OOM-kills often come from non-heap growth the heap flags don't cover — size the whole process, not just -Xmx.

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Interview Tip

Container OOMs are often non-heap — mention MaxRAMPercentage.

jvmheapmetaspace

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