May 19, 2020 · 3 Using -XX:+UseParNewGC along with -XX:+UseConcMarkSweepGC, will cause higher pause time for Minor GCs, when compared to -XX:+UseParallelGC. This is because, promotion of objects from Young to Old Generation will require running a Best-Fit algorithm (due to old generation fragmentation) to find an address for this object. Nov 25, 2015 · So what's the equivalent replacement for it? -XX:+UseG1GC? Background: The application has a heap of 8GB and creates a lot of short living objects. I noticed that it often paused for some seconds to do garbage collection. Out of curiosity I added the -Xincgc and found that the pauses were gone and overall performance improved ~4 times. Oct 10, 2020 · $ java -XX:+PrintFlagsFinal -version | grep UnlockExperimentalVMOptions openjdk version "1.8.0_265" OpenJDK Runtime Environment (build 1.8.0_265-8u265-b01-0ubuntu2~20.04-b01) OpenJDK 64-Bit Server VM (build 25.265-b01, mixed mode) Is the flag UnlockExperimentalVMOptions removed or Am I doing something wrong or what?? Jan 17, 2024 · I found it hard to decipher what is meant by "working directory of the VM". In my example, I was using the Java Service Wrapper program to execute a jar - the dump files were created in the directory where I had placed the wrapper program, e.g. c:\myapp\bin. The reason I discovered this is because the files can be quite large and they filled up the hard drive before I discovered their location. -XX:MaxPermSize=size Sets the maximum permanent generation space size. This option was deprecated in JDK 8, and superseded by the -XX:MaxMetaspaceSize option. Sizes are expressed in bytes. Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, g or G to indicate gigabytes. References: How is the java memory pool divided? According to this blog entry: Note that with recent JVM versions -XX:+UseParNewGC is enabled automatically when -XX:+UseConcMarkSweepGC is set. As a consequence, if parallel young generation GC is not desired,

it needs to be disabled by setting -XX:-UseParNewGC. For a concise summary of command line combinations, you might also be interested in this overview. Sep 8, 2009 · In any case, the -XX:-UseGCOverheadLimit flag tells the VM to disable GC overhead limit checking (actually "turns it off"), whereas your -Xmx command merely increased the heap. In the latter case the GC overhead checking was still running, it just sounds like a bigger heap solved the GC thrashing issues in your case (this will not always help). I am trying to extract the url for facebook video file page from the facebook video link but I am not able to proceed how. For example: The facebook video url I have Aug 10, 2017 · Then you should probably set a maximum size for the metaspace -XX:MaxMetaspaceSize= Metaspace Free Ratio: Do you load many different classes dynamically? Then you could maybe define a free ratio on the metaspace so that always enough space for new classes is available and no resizing will be needed in critical situations. Sep 26, 2014 · string1 = xxx-xx-xxxx or string1 = xx-xxxxxxx How can I make the regex accept both kinds of values for the same element? The x's represent numbers only. so total number of digits = 9 (anything between 0-9) total number of elements in the value is either 11 or 10 depending on which format. and total number of dashes is either 2 or 1.