JVM common parameter settings

-Server
-Xms8g
Initial heap size
-Xmx8g
Max heap size
-Xmn2g
Young Generation size
-Xss1024K
Stack size of each thread
-XX: PermSize = 256 m-XX: MaxPermSize = 512 m
Perm is not heap memory and is directly allocated by the virtual machine. You can use parameters such as-XX: PermSize-XX: MaxPermSize to adjust its size.
Set the initial value of perm gen to set the maximum value of the permanent generation.
-XX: ParallelGCThreads = 8
Number of parallel collector threads
-XX: + UseConcMarkSweepGC
Use CMS Memory for collection
-XX: + UseParNewGC
Set Young Generation for parallel collection
-XX: + UseConcMarkSweepGC
Use CMS Memory for collection
-XX: + UseCMSCompactAtFullCollection
Compression of the old generation during FULL GC
-XX: Required vorratio = 4
Ratio of Eden to vor
-XX: MaxTenuringThreshold = 10
Maximum age of Spam
-XX: CMSInitiatingOccupancyFraction = 80
Use cms for garbage collection. Use 80% to start CMS collection.