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Update Release Notes Index
About 1.6.0_20 (6u20) for the Itanium® architecture

1.6.0_20 for the Itanium® architecture is a port of JDK 6 update 20 to the Itanium® (64 bit) architecture.

The full internal version number for this update release is 1.6.0_20-b0201 (where "b" means "build"). The external version number is 6u20. Included in JDK 6u20 for the Itanium® architecture is version 16.3 of the Java HotSpot Server Virtual Machine.

The following JDK, JRE tools are not included in JDK, JRE 6u20 for the Itanium® architecture release:

  • Java Plug-in
  • Java Web Start
  • Java Update
  • JavaDB (JavaDB is included only into Linux self-extracting JDK distributive)
  • Java VisualVM


Please refer to JDK tools and Utilities for JDK tools description.

Only offline installation is available for JDK, JRE 6u20 for the Itanium® architecture.

Changes in 1.6.0_20 (6u20) for the Itanium® architecture

 

  • See changes in 1.6.0_20 common for all platforms in Java SE 6 Update 20 Release Notes.

     

  • Bug fixes

    This release contains fixes for security vulnerabilities. For more information, please see Oracle Security Alert for CVE-2010-0886.

  • Performance

    The following set of command line options are recommended for running high performance server applications:

    -XX:+AggressiveOpts
    -XX:+AggressiveHeap
    -XX:ParallelGCThreads=2
    -XX:InterpreterProfilePercentage=10
    -XX:CompileThreshold=35000
    -XX:OnStackReplacePercentage=80
    -XX:PermSize=256m
    -XX:MaxPermSize=256m
    -XX:AllocatePrefetchStepSize=128
    -XX:AllocatePrefetchStyle=2
    -XX:AllocatePrefetchDistance=1024
    -XX:+UseCompressedOops if heap size is less than 32GB
    -Xmx, -Xms, -Xmn should have sufficiently large values. For example, -Xms6656m -Xmn5120m -Xmx6656m or -Xms26624m -Xmn21248m -Xmx26624m. The value of the PH*PH*PH\uFFFDPH*PH*PHXmn option should be less than about 80% of the PH*PH*PH\uFFFDPH*PH*PHXmx value.



Supported System Configurations

 

 

Platform Version Desktop Managers Browsers JRE JDK
Windows 64 bit
Windows IA64 Windows Server 2003 SP2 Windows/Active for Windows
N/A
64-bit Install 64-bit Install
Windows Server 2008 for Itanium-based Systems SP1
Linux 64 bit
Linux IA64 SUSE Enterprise Linux Server 10 SP2,
SUSE Linux Enterprise Server 11
N/A
N/A
64-bit Install 64-bit Install
Red Hat Enterprise Linux 4.0 U7,
Red Hat Enterprise Linux 5.0 U2


JDK, JRE Installation for Microsoft Windows (Itanium® architecture)

The installation procedure installs the JDK or JRE 6u20 but not the Java Plugin or Java Web Start.

To install, download jdk-6u20-windows-ia64.exe or jre-6u20-windows-ia64.exe file and then follow the 32-bit Windows JDK installation or 32-bit Windows JRE installation "Windows Offline Installation" instructions.

Note, during JRE installation Java executables including java.exe are not copied to the Windows System directory.

JDK, JRE Installation for Linux (Itanium® architecture)

The installation procedure installs the JRE or JDK 6u20 but not the Java Plugin or Java Web Start.

The JDK, JRE for Linux 64-bit comes bundled in two install formats:

  • Linux self-extracting files jdk-6u20-linux-ia64.bin, jre-6u20-linux-ia64.bin and
  • Linux RPM in self-extracting files jdk-6u20-linux-ia64-rpm.bin, jre-6u20-linux-ia64-rpm.bin.


To install, download the necessary file and then follow one of the 32-bit Linux JDK RPM Installation, 32-bit Linux JDK Self-Extracting Binary Installation or 32-bit Linux JRE RPM Installation, 32-bit Linux JRE Self-Extracting Binary Installation instructions.

Known installation issues

 

  • On Linux systems, when the *-rpm.bin file is used for JDK (JRE) installation, JDK (JRE) of a lower version cannot be installed if JDK (JRE) of a higher version is already installed on the same system.

    For example, JDK (JRE) 6u16 cannot be installed using the jdk(jre)-6u16-linux-ia64-rpm.bin file if, on the same machine, JDK (JRE) 6u20 was previously installed using jdk(jre)-6u20-linux-ia64-rpm.bin.

    Installation reports:

    Preparing... ########################################### [100%]
    package jdk-1.6.0_20-fcs (which is newer than jdk-1.6.0_16-fcs) is already installed
    JDK (JRE) 6u16 is not installed.

    Workarounds are:

    • Uninstall JDK (JRE) 6u20, then install JDK (JRE) 6u16 using jdk(jre)-6u16-linux-ia64-rpm.bin, or
    • Install JDK (JRE) 6u16 using the jdk(jre)-6u16-linux-ia64.bin file


    If JDK (JRE) 6u20 was installed using jdk(jre)-6u20-linux-ia64.bin, installation of JRE (JDK) 6u16 using jre(jdk)-6u16-linux-ia64.bin passes successfully.

    See also 6673415.

  • On Windows systems after installation of JDK (or JRE) the registry keys "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit\1.6" (for JDK), "HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.6" (for JRE) should contain the value "JavaHome" with the full path name of the directory in which JDK (or JRE) of the highest version is installed.

    However, in 6u17 and earlier releases of JDK, JRE for the Itanium® architecture, after installation of JDK (or JRE) of a lower version on top of a higher version (for example, 6u16 on top of 6u20), "JavaHome" contains the path to the last installed JDK (or JRE) instead of the path to the JDK (or JRE) of the highest installed version. After uninstallation the value is removed.

    The workaround is to put the correct value to the Windows registry manually. A more accurate workaround is to uninstall the previously installed JDK (or JRE) and install the required version. See Deploying the JRE on Windows for more details about registry values.

    The issue was fixed in JDK, JRE 6u18 for the Itanium® architecture release.



Known issues and limitations

 

  • The JVM can intermittently crash with SIGILL on Linux RHEL4 for the Itanium® architecture when executed from an NFS mounted directory.

    This is a known bug in kernels of versions less than 2.6.22. Processors older than Montecito (e.g. Madison, McKinley) are not affected. Details can be found here: http://www.gelato.unsw.edu.au/archives/linux-ia64/0707/20656.html.

    RHEL4 (Nahant Update 5), kernel 2.6.9-55.EL has this bug. In RHEL5.2(Tikanga), kernel 2.6.18-92.el5 the bug is fixed.

    Possible workarounds are:

    • Run Java from a local directory.
    • Migrate to a newer kernel in which this bug is fixed, for example, to RHEL5.2 or RHEL4.6.
    • Apply the patch linux-2.6-mm-ia64-flush-i-cache-before-set_pte.patch (from kernel-2.6.18-92.el5.src.rpm) to your kernel.



 



 

  • Serviceablity Agent (SA) issues:

     

    • SA can fail to show thread stack frames; instead it throws InternalError with diagnostic message ‘Failed to decode stack’.
      Workaround: for running processes use JVMTI Agent.

    • SA can fail to show some local variables of stack frames; instead it throws an unexpected exception (typically, NullPointerException or AssertionFailure).
      Workaround: try to start JVM with the –XX:+FullSASupport option.

    • Sometimes SA can show incorrect values for Long and Double locals.
      Workaround: for running processes use JVMTI Agent.

    • On Windows SA does not accept a dump file generated by default (the MiniDumpNormal type of information that is written to the minidump file).
      Workaround: specify the –XX:ErrorDumpLevel=2 JVM option (MiniDumpWithFullMemory type).

    • jstack (an experimental tool) does not print the mixed mode (both Java and native C/C++ frames) stack trace when the option -m is specified; an exception with diagnostic "not yet implemented (debugger does not support CDebugger)!" is thrown. The reason is that CDebugger is not implemented for the Itanium® architecture.
      Workaround: do not use the -m option or use a different tool.




 



 

  • Java 6 does not support Sun PKCS#11 and SunMSCAPI providers for Windows 64-bit (see native security features availability in various operating systems in Leveraging Security in the Native Platform Using Java SE 6 Technology article). These providers are not a part of Java 6 for Windows Itanium® architecture. If necessary, one can use implementations of these providers offered by third parties.