java heap size:設定運行時的堆大小

When you are using JVM in 32-bit mode, the maximum heap size that can be allocated is 1280 MB. So, if you want to go beyond that, you need to invoke JVM in 64-mode.

You can use following:

$ java -d64 -Xms512m -Xmx4g HelloWorld

where,

• -d64: Will enable 64-bit JVM
• -Xms512m: Will set initial heap size as 512 MB
• -Xmx4g: Will set maximum heap size as 4 GB

You can tune in -Xms and -Xmx as per you requirements (YMMV)

http://stackoverflow.com/questions/3030263/increasing-the-jvm-maximum-heap-size-for-memory-intensive-applications

參考weblogic jvm設置官方博文：

https://docs.oracle.com/cd/E15523_01/web.1111/e13814/jvm_tuning.htm#PERFM156

JVM Tuning: Heapsize, Stacksize and Garbage Collection Fundamental

http://crunchify.com/jvm-tuning-heapsize-stacksize-garbage-collection-fundamental/