Running 32 bit java, tomcat etc on 64bit WIndows OS

[zigzagdna]

If I have Windows 2003 OS which is 64 bit, can I install 32 bit java,
Apache tomcat etc on it without any problem. I know on HP UNIX 64 bit,
32 bit application runs without problem, I would think same is true on
Windows 2003 OS.

I am assuming I will be able to hav elarger hepa memory e.eg. for
Java. With 32 bit OS, maximum java heap memory is limited to around
1500M. With 64GB I am hoping I can get 3GB to 4GB. I know 32bit java
canno access more than 4GB, but I should be bale to have heap memory
up to 4GB.

 

[zigzagdna]

There have already been a number of relevant discussions here.  You can
find them like this:http://groups.google.com/group/comp.lang.java.programmer/search?q=gro...

As far as the specific questions, the short answers are:

    32-bit programs run fine on 64-bit Windows, for the most part.
Java should be fine

    If the JVM has the /LARGEADDRESSAWARE executable flag set, you
should be able to get up to almost 4GB on 64-bit Windows

There are always things in the process address space taking up room
other than the heap, so you'll never get the full 4GB.  But you can do a
lot better than 1.5GB on 64-bit Windows, for an application with the
/LARGEADDRESSAWARE flag set.

For applications that do not have the /LARGEADDRESSAWARE flag set, you
can experiment and see if setting it works, but it's a potentially risky
thing to do.  I think most applications should work fine like that, but
if you're not the developer of the application, you never know when
someone's done something screwy with a pointer variable.

Pete

Thanks a lot for quick response.

 

[Roedy Green]

If I have Windows 2003 OS which is 64 bit, can I install 32 bit java,
Apache tomcat etc on it without any problem. I know on HP UNIX 64 bit,
32 bit application runs without problem, I would think same is true on
Windows 2003 OS.

You will likely want both 32 bit and 64 bit Java installed. You may
have to manually add a missing JVM to the Java control panel.

Applets and Java Web Start only work with 32-bit Java.

 

[Lew]

Applets and Java Web Start only work with 32-bit Java.

That's funny. Both have worked quite well on my 64-bit Java for quite a
while. (JRE 6u17, Ubuntu Linux, AMD 64b CPU, Firefox 3.0.15)

It seems that capability was added back in 6u12, around six months ago:
<http://java.sun.com/javase/6/webnotes/6u12.html>

mindprod.com is an important and usually quite reliable source of information
about Java, especially for newbies, and you promote it heavily in this
newsgroup. Please ensure your information is accurate.

 

[Kevin McMurtrie]

You will likely want both 32 bit and 64 bit Java installed. You may
have to manually add a missing JVM to the Java control panel.

Applets and Java Web Start only work with 32-bit Java.

Not true, it depends on the environment. Applets that run inside the
browser's process must use a JVM matching the browser's CPU
architecture. (There are 64 bit browsers.) Applets that run in their
own process can be whatever the OS supports.

 

[Arne Vajhøj]

You will likely want both 32 bit and 64 bit Java installed. You may
have to manually add a missing JVM to the Java control panel.

Applets and Java Web Start only work with 32-bit Java.

.... a couple of years ago.

Arne