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http://www.oracle.com/technetwork/java/javase/tech/g1-intro-jsp-135488.html seems to be the official docs for the G1 garbage collector.

There are two options mentioned:

  • -XX:+G1ParallelRSetUpdatingEnabled
  • -XX:+G1ParallelRSetScanningEnabled

When configuring tomcat to use G1 with these options, catalina.log shows up

Unrecognized VM option '+G1ParallelRSetUpdatingEnabled'
Could not create the Java virtual machine.

My JVM is

$ java -version
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)

and

JAVA_OPTS="-server -Djava.awt.headless=true -Xmx3G -Xss512k -XX:MaxPermSize=1G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:+G1ParallelRSetUpdatingEnabled -XX:+G1ParallelRSetScanningEnabled"

Any hints why -XX:+G1ParallelRSetScanningEnabled does not work?

Stefan Armbruster
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    Check this: http://stackoverflow.com/questions/8262674/java7-g1-options/8263201#8263201 –  Nov 24 '11 at 22:51

2 Answers2

2

It's been disabled. See this question and my answer.

The documentation that you are linking to, as its name may or may not clearly suggest, was at the time the introduction of G1 to the world (not introduction as in "starter guide"). Things have evolved since.

Community
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haylem
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0

G1 was officially introduced by Oracle in Java 7 U4: http://www.oracle.com/technetwork/java/javase/7u4-relnotes-1575007.html

You can find the official documentation here: http://docs.oracle.com/javase/7/docs/technotes/guides/vm/G1.html

and command line options here: http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html#G1Options

Florakel
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