I am happy to inform you that I published recently an update to the existing refcard on Java Performance Optimization which is now available from DZone. The updated material now better reflects the Java 8 features and provides a dedicated section and guidelines about the JVM Metaspace.
For now, find below a small snippet:
“By default, the Metaspace memory space is unbounded and will use the available process and/or OS native memory available for dynamic expansions. The memory space is divided into chunks and allocated by the JVM via mmap. We recommend keeping the default, dynamic resize mode as a starting point for simpler sizing combined with close monitoring of your application metadata footprint over time for optimal capacity planning…”