Java Memory Management Best Practices
summary
Java defaults give a max heap of a quarter of physical RAM and often surprise; set -Xmx explicitly, use jcmd to take heap dumps (beware health checks and storage), analyze dumps with Eclipse Memory Analyzer or Microsoft GC Toolkit, and profile native allocations with async-profiler or JNM tracking. Recent JDKs (24/25) add compact object headers; metaspace should be bounded to catch leaks; direct buffers count against native memory; string deduplication has a default threshold of three; GC overhead limit triggers at 98%.
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chapters (9)
- 0:00Introduction
- 1:20Memory basics and constraints
- 4:49JVM memory configuration
- 11:26Optimizing JVM environment
- 18:01Heap dump analysis
- 23:56Advanced memory optimizations
- 28:46Native memory and code cache
- 34:06GC throughput and logging
- 38:54Strings, collections, and closing
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