Java on HP-UX 11i Frequently Asked Questions

Q: How do I tell the latest version of Java available?
A: See the HP-UX 11i Java home page for the most current releases available for
download. Or go to the Software Depot Java download page for a list of all available
Java product releases.
Q: Where can I find additional FAQs about Java?
A: You can try the following websites: www.jguru.com/faq/ and Oracle's Source for
Developers website at http://www.oracle.com/technetwork/java/index.html.
Q: What is HP's support-life policy for Java 1.4.2?
A: HP's standard policy for Java is to support three major release lines simultaneously,
which are currently Java 1.4.2, Java 5, and Java 6. Under this policy, HP will continue
to support Java 1.4.2 until Java 7 is released, which will be no sooner than February
2011. HP is committed to supporting Java 1.4.2 until February 2011 or the release of
Java 7, whichever is later.
Q: Does a 64-bit JDK for either Windows or Linux running on IA-64 exist?
A: HP does not support Windows or Linux on Itanium. The recommended solution is
Oracle/Sun Java 6 product for Itanium®.
Technical Questions
Q: How can I break the HotSpot 3.5 GB maximum heap size barrier?
A: The best way to do this is to use our 64-bit binaries to get past the heap size
limitations. You do this by adding the -d64 option to the command line. Java options
are documented in the “HotSpot Technology Tools and Commands” section of the
HP-UX Programmer's Guide for Java 2 on the Business Support Center at:
http://www.hp.com/go/hpux-java-docs.
Q: I am running Java code on an HP-UX 11i v2 machine, and the process dies after
about 245 threads. Why aren't more threads supported?
A: You need to check your kernel parameters. The max_thread_proc parameter defines
the maximum number of kernel threads allowed per process. The default values for
max_thread_proc are:
• HP-UX 11i v1 (11.11): 64 threads
• HP-UX 11i v2 (11.23): 256 threads
• HP-UX 11i v3 (11.31): 256 threads
Your 245 threads plus the threads in the JVM are exceeding the limit. Use HPjconfig
(free download available from HPjconfig on SW Depot) to set your kernel parameters
to optimal values for Java.
Technical Questions 7