Upgrading Oracle JRockit JDK

This document contains information that will help you upgrade to the latest version of the Oracle JRockit JDK. It contains information on the following subjects:

Supported Configurations

Please make sure that the Oracle JRockit JVM is deployed on a supported configuration. If it isn’t, you will have to upgrade your configuration. For details on all supported configurations, please refer to Oracle JRockit JDK Supported Configurations at:

Upgrading from an Earlier Release

This section contains information critical to successfully upgrading your version of the JRockit JDK to version R27. It includes information on the following subjects:

Java Standard Edition (Java SE) Dependencies

J2SE 1.4.2

Oracle JRockit JDK 1.4.2 R26 and R27 are certified against J2SE 1.4.2 and it includes the Sun J2SE class libraries for J2SE 1.4.2. Please make sure that your application is compliant with J2SE 1.4.2. For verification, please refer to:

J2SE 5.0

Oracle JRockit JDK 5.0 R26 and R27 are certified against J2SE 5.0 and it includes the Sun J2SE class libraries for J2SE 5.0. Please make sure that your application is compliant with J2SE 5.0. For verification, please refer to:

Java SE 6

Oracle JRockit JDK 6 R27 is certified against Java SE 6 and it includes the Sun Java SE class libraries for Java SE 6. Please make sure that your application is compliant with Java SE 6. For verification, please refer to:

Upgrading from Oracle JRockit JDK 5.0 R26

No additional procedures are required to upgrade to Oracle JRockit JDK 5.0 R27 from Oracle JRockit JDK 5.0 R26.

Upgrading from Oracle JRockit JDK 1.4.2 R26

No additional procedures are required to upgrade to Oracle JRockit JDK 1.4.2 R27 from Oracle JRockit JDK 1.4.2 R26.

Upgrading from Oracle JRockit JDK 1.4.2 R24

Oracle JRockit JDK 1.4.2 R24 was certified against J2SE 1.4.2, which is the same J2SE version that Oracle JRockit JDK 1.4.2 R27 has been certified against. Your application should already be compatible with J2SE 1.4.2.

Upgrading from Oracle JRockit JDK 8.1

Oracle JRockit JDK 8.1 was certified against J2SE 1.4.1. Make sure that you application is compatible with J2SE 1.4.2. Please refer to the section Java Standard Edition (Java SE) Dependencies for further details.

Upgrading from Oracle JRockit JDK 7.0 SP6 R23

Oracle JRockit JDK 7.0 SP6 R23 was certified against J2SE 1.3.1. Make sure that you application is compatible with J2SE 1.4.2.

Special Note on Upgrading to JRockit JVM R26 and R27

JRockit JVM R26 and R27 represent new, major JVM releases when you upgrade to it from any of these releases:

By simply replacing your existing JVM with this version and making no or minimal changes to your application, JRockit JVM R26 and R27 will deliver:

Practical Upgrading

This section includes information that you will find helpful when upgrading to JRockit JVM R27. It includes information on these subjects:

The JVM Version

To verify the installation, check the version string by issuing the command java -version. The JRockit JDK version information, for example, Oracle JRockit JDK 1.4.2_15 R27.4.0 is comprised of two elements

Startup Options

As a rule of thumb, consider as few startup options as possible. Please make sure that all startup options are well understood and required.

Some -XX options might have changed. For more information of how options can be changed, please refer to Compatibility Between Releases at:

Testing Your Application in a Staging Environment

Please make sure to test your application in a controlled staging environment before upgrading your production environment. The staging environment should be as similar to your production environment as possible. This includes hardware, software, usage patterns and load.

Applications are sometimes sensitive to timing. A JRockit JVM upgrade can sometimes expose errors in your application; for example, dependencies on unspecified behavior or APIs. Timing differences introduced when upgrading the JVM may for instance expose erroneous synchronization.

Release Notes

This section contains important information regarding release information that might have some impact on upgrading from one version of the JRockit JVM to another. It contains the following subjects:

Changes to Intermediate Releases

Be careful when reading the recent changes in the release notes; be sure to read about the changes happening in intermediate version upgrades up to R27. For a list of the changes in intermediate versions, please refer to the release notes for each version:

Noticeable Changes

Following is a list of some of the changes that might indicate that your application could behave differently after upgrading to R27. These changes include:

Updated Command-line Options

The rules for how command-line parameters are parsed have been updated to avoid user confusion. Incompatible command-line combinations now cause JRockit JVM to print out an error message and terminate. Please refer to the specific option in the Oracle JRockit JVM Command-Line Reference (by clicking on the option name in Table 1) for a description of the new behavior.

Table 1 Updated Command-line Options
-X options	-XX options
`-Xgc`	`-XXallocClearChunks`
`-XgcPrio`	`-XXallocClearChunkSize`
`-Xms`	`-XXallocPrefetch`
`-Xmx`	`-XXallocRedoPrefetch`
`-Xns`	`-XXcompactSetLimit`
`-XpauseTarget`	`-XXcompactSetLimitPerObject`
	`-XXcompactRatio`
	`-XXcompressedRefs`
	`-XXdisableFatSpin`
	`-XXdisableGcHeuristics`
	`-XXexternalCompactRatio`
	`-XXfullCompaction`
	`-XXfullSystemGc`
	`-XXinternalCompactRatio`
	`-XXlargeObjectLimit`
	`-XXminBlockSize`
	`-XXnoCompaction`
	`-XXnoSystemGc`
	`-XXpointerMatrixLinnearSeekDistance`
	`-XXsetGC`
	`-XXstaticCompaction`
	`-XXthroughputCompaction`
	`-XXtlaSize`
	`-XXusePointerMatrix`
	-XX:(+\|-)useNewHashFunction
	-XX:(+\|-)useThreadPriorities

Support for Larger Heaps

It is now possible to make use of a larger part of the process memory for the java heap as the demand for continuous heap has been removed.

Garbage Collection

The new default garbage collection strategy is -Xgcprio:throughput. A new feature -XpauseTarget is implemented to specify desired maximum pause time. The Generational Copy collector, started with -Xgc:gencopy has been removed. For more information on garbage collection in the Oracle JRockit JVM, please refer to Memory Management Basics at:

References API

New implementation of how softly reachable references are collected. The -Xverbose:references output has been enhanced. For more information, please refer to the -Xverbose section in the Oracle JRockit JVM Command-Line Reference at

Client Application Deployment Technologies

Tools — JRockit Mission Control

The monitoring and management tools now require a license. A free development license is available to test the tools in a development environment and limited to work only during the first hour of any application run; that is, restarting the application will allow another hour of tools testing. For more information on JRockit Mission Control licensing, please refer to JRockit Mission Control documentation at:

Oracle JRockit Mission Control includes the Management Console, JRockit Runtime Analyzer and the Memory Leak Detector. The Management Console can be used without a license but is then not eligible for support.

Upgrade Guide