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Did anyone experience similar issue? any inputs and suggestions for resolving this issue is much appreciated.
Same behavior is observed for “-XX:-CMSPermGenPrecleaningEnabled" JVM CMS gc option, any help on this is much appreciated.
No problems here:
When we put in an option, for example, -XX:SomethingNotRight, it outputs the following:
[user@machine1 ~]$ java -server -d64 -Xms1024m -Xmx1024m -XX:NewRatio=3 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -version java version "1.7.0_09-icedtea" OpenJDK Runtime Environment (rhel-22.214.171.124.el6_4-x86_64) OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)
Also why are you setting these (-XX:ConcGCThreads=1 -XX:-CMSParallelRemarkEnabled) parameters? Are you running on a machine with a small numbe of CPU's (cores)? If yes it is better to run the CMS collector in incremental mode, for example,
[user@machine1 ~]$ java -server -d64 -Xms1024m -Xmx1024m -XX:NewRatio=3 -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SomethingNotRight -version Unrecognized VM option 'SomethingNotRight' Error: Could not create the Java Virtual Machine. Error: A fatal exception has occurred. Program will exit.
Note that when running with CMS it is advisory set CMSParallelRemarkEnabled on (-XX:+CMSParallelRemarkEnabled - think this is the default anyway). This enables multiple parallel threads to participate in the remark phase of the CMS algorithm. As this is a stop the world phase it is good practice to use as many cores as possible and thus reducing the time it is stopping.
-server -Xms1024m -Xmx1024m -XX:NewRatio=2 -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:+CMSIncrementalPacing