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Sixteen guides, grouped by topic. Each one lists the official documentation it is based on.

Memory

OutOfMemoryError: Direct buffer memory and MaxDirectMemorySize
The off-heap NIO buffer limit, its default, and how to measure and fix direct memory use.
The JIT code cache: ReservedCodeCacheSize and "CodeCache is full"
Default sizes, the segmented code cache, monitoring and when to raise the limit.
GC roots and Java memory leaks
What keeps objects alive, the usual accidental references, and tracing a leak to its root.
Taking and reading a Java heap dump
jcmd, jmap, HeapDumpOnOutOfMemoryError and Eclipse Memory Analyzer.
Metaspace explained
Class metadata, MaxMetaspaceSize, the compressed class space and class loader leaks.
The AI memory squeeze: DRAM prices, cloud costs and what it changes for JVM teams
Sourced memory price figures, the cost of a gigabyte in the cloud, and how to need fewer of them.
Native Memory Tracking
Why the JVM uses more than -Xmx, baselines and diffs, and what NMT cannot see.

Choosing a HotSpot garbage collector
Serial, Parallel, G1, ZGC and Shenandoah, and what the JVM picks by default.
Tuning G1 in production
Heap size, pause target, IHOP, humongous objects and the flags to leave alone.
Reading GC logs with -Xlog:gc
Unified logging setup, legacy flag mapping and the patterns that matter.

Reading Java thread dumps
jcmd Thread.print and jstack, thread states, lock lines and deadlocks.
High CPU in a Java process: finding the thread
top -H, the nid in thread dumps, and profiling with Flight Recorder.
Virtual threads in production
JEP 444, pinning before and after JDK 24, and what to monitor.

The JVM in containers
UseContainerSupport, MaxRAMPercentage and a memory budget that avoids the OOM killer.
Keeping AI products affordable
Batching, quantisation and caching, and sizing the Java services around a model.
Java Flight Recorder and JDK Mission Control
Continuous recordings, on-demand dumps and reading .jfr files.