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Basic Java Flags

Can be used to optimize a server or program.

Memory allocation

Flag	Description
-Xms	Minimum allocated memory for Heap
-Xmx	Maximum allocated memory for Heap
-Xss	Allocated memory for Stack

Main flags

Flag	Description	Note
-XX:+DisableAttachMechanism	Disable the attachment mechanism that allows agents to be loaded into the JVM
-Xincgc	Activates the garbage collector, which will unload unused RAM from time to time. The collector type is chosen depending on the version of Java.
-server	Java server activation. Speeds up the compilation of classes, which gives a performance boost, but increases the startup time.	Only for Java x64
-Dfile.encoding=UTF-8	UTF-8 encoding
-XX:AutoGCSelectPauseMillis=3000	The time in milliseconds between calls to the automatically selected garbage collector.
-XX:+UseConcMarkSweepGC	Activating a garbage collector that uses multiple threads
-XX:ConcGCThreads=2	Number of threads for garbage collector
-XX:+UseSerialGC	Garbage collector that runs on a single thread

Additional for optimization

Flag	Description	Note
-XX:+AggresiveOpts	Activating Java Experimental Arguments
-XX:-UseGCOverheadLimit	Ignores low memory for garbage collection
-XX:+UseCompressedOops	Reducing the size of the pointer, headings, as well as shifts within the created objects.
-XX:+OptimizeFill	Allows you to translate array fill/copy cycles into direct machine instructions.
-XX:+OptimizeStringConcat	Optimization of the concatenation operation.