JVM memory configuration parameter GC log

GC log:
For JVM memory configuration parameters:

-Xmx10240m -Xms10240m -Xmn5120m -XXSurvivorRatio=3
-Xmx10240m: represents the maximum heap

-Xms10240m: represents the minimum heap, initial allocation

-Xmn5120m: represents the new generation

-XXSurvivorRatio=3: represents Eden:Survivor = 3 According to the Generation-Collection algorithm (the algorithm used by most JVMs at present), the heap memory is generally divided into several different areas according to the life cycle of the object.Divided into Eden, two Survivors; Calculate the size of Survivor, Eden: Survivor = 3, the total size is 5120, 3x+x+x=5120 x=1024

Most of the new generation needs to be recycled, using the Copying algorithm, fast!

Most of the old age do not need to be recycled, and the Mark-Compact algorithm is used

You can use this command to set the java running memory when running the jar program:

java -Xms2048m -Xmx2048m -Xmn512m -jar XXXX.jar

https://blog.csdn.net/m0_47914176/article/details/123706946
-Xss1m: The stack size in the HotSpot version is fixed and does not support expansion.java.lang.StackOverflowError
The general method call is difficult to appear, if it appears, it may be infinite recursion

-XX:MetaspaceSize=256M: The initialization threshold for triggering FullGC when Metaspace is expanded, which is also the minimum threshold
-XX:MetaspaceSize: Set the size of the metaspace
-XX:MaxMetaspaceSize: Set the maximum size of the metaspace
-XX:+UseParNewGC: will be automatically activated with concurrent lifetime generation garbage collection
-XX:+UseConcMarkSweepGC: concurrent mark sweep, i.e. use CMS collector
-XX:+PrintGCDetails: print gc details
-Xloggc:gc.log: Output the GC log to the gc.log file
The -XX:+HeapDumpOnOutOfMemoryError parameter indicates that when the JVM occurs OOM, the DUMP file is automatically generated
When using -XX:HeapDumpPath configuration, you need to ensure that the folders of the directory exist, because it will not help you to create non-existing directories when dumping files everywhere.