24

Jun 09

Java: GC Options

Verbose GC options

Option Default value Max Value Description
-XX:+PrintGCDetails false PrintGC details
-XX:+PrintGCTimeStamps false Adds timestamp info to GC details
-XX:+PrintHeapAtGC false Prints detailed GC info including heap occupancy before and after GC
-XX:+PrintTenuringDistribution false Prints object aging or tenuring information
-XX:+PrintHeapUsageOverTime false Print heap usage and capacity with timestamps
-Xloggc:filename false Prints GC info to a log file
-verbose:gc false Prints some GC info
-XX:+PrintTLAB false Print TLAB information


Parallel Scavenge Collector

Option Default value Max Value Description
-XX:UseParallelGC Enables young generation parallel scavenge collector. Works only with the default mark-sweep-compact collector. Do not use with the concurrent collector.
-XX:+UseAdaptiveSizePolicy false Automatically sizes the young generation and chooses an optimum survivor ratio to maximize performance.
-XX:+PrintAdaptiveSizePolicy false Prints information about adaptive size policy
-XX:ParallelGCThreads As many threads as CPUs Controls the number of threads used for copying collection

Parallel Copying Collector

Option Default value Max Value Description
-XX:+UseParNewGC Enables young generation parallel copying collector. Use with concurrent collector or default mark-sweep-compact collector
-XX:ParallelGCThreads As many threads as CPUs Controls the number of threads used for copying collection

No comments yet, be the first.

Leave a Reply