java native memory

• https://openjdk.java.net/jeps/370
• https://dzone.com/articles/troubleshooting-problems-with-native-off-heap-memo
• https://www.javacodegeeks.com/2016/03/jcmd-one-jdk-command-line-tool-rule.html

DirectByteBuffer

• ByteBuffer.allocateDirect() 로 할당 받음
• 조정 옵션
  • -Djdk.nio.maxCachedBufferSize
  • -XX:MaxDirectMemorySize

Netty

• https://github.com/netty/netty/blob/4.1/common/src/main/java/io/netty/util/internal/PlatformDependent.java#L192
• Dio.netty.noPreferDirect=true

Linux command

• cat /proc/meminfo
• cat /proc/{pid}/status