Difference between -XX:+UseParallelGC and -XX:+UseParNewGC 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
java - Difference between -XX:MaxPermSize=size and -XX:MaxMetaspaceSize . . . What is the difference between -XX:MaxPermSize and -XX:MaxMetaspaceSize options in terms of memory settings? The difference between -XX:MaxPermSize and -XX:MaxMetaspaceSize is largely moot -XX:MaxPermSize was for sizing the old "permanent generation" (PermGen) heap This was removed in Java 8 XX:MaxMetaspaceSize is for sizing the new "Metaspace" off-heap memory space that is used by the JVM
Regular Expression to validate xx-xxxxxxx or xxx-xx-xxxx 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
Difference between Xms and Xmx and XX:MaxPermSize -XX:MaxPermSize=size Sets the maximum permanent generation space size This option was deprecated in JDK 8, and superseded by the -XX:MaxMetaspaceSize option Sizes are expressed in bytes Append the letter k or K to indicate kilobytes, m or M to indicate megabytes, g or G to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?
Is -XX:+UseG1GC the correct replacement for -Xincgc? 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
java - Why should we set -XX:InitialRAMPercentage and -XX . . . In addition, setting -XX:InitialRAMPercentage and -XX:MaxRAMPercentage may take away some flexibility in the heuristic configuration of the garbage collector, which may mean you have to do more explicit tuning yourself to get the best performance
What exactly does -XX:-TieredCompilation do? - Stack Overflow Using java -XX:+PrintFlagsFinal I found the TieredCompilation flag, and I read about it a bit online Yet, I still don't know exactly what happens when setting it to false I know that the compil