1 Introduction

This document provides simple guidelines to help migrate applications from Oracle JRockit to Java HotSpot VM (HotSpot). It contains sections for each JVM system component that describe the equivalents of those components in both Oracle JRockit and HotSpot. The document also lists the corresponding JVM options of those components. It includes tables that map the complete set of Oracle JRockit -X and -XX command-line options to the ones available in HotSpot.

Note:

Some of the tools described in this document require a commercial license for use in production. To learn more about commercial features and how to enable them, see Oracle Java SE Advanced and Oracle Java SE Suite.

Heap Sizing

HotSpot has the same options as Oracle JRockit to set the initial and the maximum Java heap size.

Table 1-1 Heap Size

Option	Oracle JRockit	HotSpot
`-Xms`	Sets the initial and minimum size of the heap	Sets the initial and minimum size of the heap
`-Xmx`	Sets the maximum size of the heap	Sets the maximum size of the heap

Note:

When migrating from Oracle JRockit to HotSpot, the Java heap size must essentially be the same.