Java – application server maximum memory limit

How much memory can servers (JBoss, Tomcat, etc.) use? For example, if the server has 128GB of memory, can it use at least 100GB of memory? I am using these parameters for my local:

-Xms512m -Xmx1024m -XX:PermSize=256m -XX:MaxPermSize=512

Can these parameters be configured to use 100GB?

Solution

We use it to run a 24GB 64 bit JVM and perform a sub second GC pause while providing 100 requests per second:

-Xms24g -Xmx24g -XX:MaxPermSize=256m -XX:NewRatio=4 -XX:SurvivorRatio=8    
-XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+DisableExplicitGC  
-XX:+UseCMSInitiatingOccupancyOnly -XX:+CMSClassUnloadingEnabled  
-XX:+CMSScavengeBeforeRemark -XX:CMSInitiatingOccupancyFraction=68

If the server has memory, there should be no reason to specify 100GB Since we use less than 32GB, we also use - XX: usecompresedoop to reduce the overhead of 64 bit addressing In addition, we use - XX: uselargepages for better performance, but you must first enable large page support for your operating system