Production HotSpot JVM Tuning Matrix

Operating dynamic bytecode engines requires careful JVM flag tuning to avoid long GC pauses and Metaspace starvation.

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Recommended Production Flags

java -server \
     -XX:+UseG1GC \
     -XX:MaxGCPauseMillis=200 \
     -XX:InitiatingHeapOccupancyPercent=45 \
     -XX:MaxMetaspaceSize=256m \
     -XX:SoftRefLRUPolicyMSPerMB=1000 \
     -XX:CompileThreshold=10000 \
     -XX:MaxInlineSize=35 \
     -XX:FreqInlineSize=325 \
     -XX:+TieredCompilation \
     -XX:+UseCompressedOops \
     -jar engine-core-1.0.0-SNAPSHOT.jar execute ...

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Flag Justification & Mechanical Sympathy

JVM Flag	Recommended Value	Engineering Rationale
-XX:+UseG1GC	Default	Predictable low-latency GC pauses for mixed short-lived contexts and long-lived compiled class references.
-XX:MaxGCPauseMillis=200	100 - 200	Bounds Stop-The-World (STW) pause times to meet strict API latency SLAs.
-XX:MaxMetaspaceSize=256m	256m	Hard cap preventing uncollected ClassLoaders from exhausting physical host memory.
-XX:SoftRefLRUPolicyMSPerMB	1000	Retains L2 soft cache entries for 1 second per free MB of heap space before GC reclamation.
-XX:CompileThreshold=10000	10000	Invocation count at which C2 triggers aggressive server optimizations.
-XX:MaxInlineSize=35	35 (bytes)	Restricts non-frequent bytecode method inlining to prevent I-Cache thrashing.
-XX:FreqInlineSize=325	325 (bytes)	Allows hot CompiledRule::eval methods to inline directly into call sites.