Interoperability of 32 bit and 64 bit

Question

Hi,
I have a production system running on Solaris 8 , 32 bit. This system runs across 10 boxes communicating through a native architecture using sockets, threads and message passing through object serialization.
Now, my client wants to add a M4000 box (Ultrasparc VI 64 bit.). This machine has to coexist with the existing boxes on Solaris 8. I will recompile my application on Soalris , SUn C++ 5.9 (Sun studio 12) to run on the M4000 box. My questions is:
1. Option 1 - Shall i do a 32 bit build. Will it run without any problem on UltraSparc VI Solaris 10 and work fine with existing build on Soalris 8 machines.
2. Option 2 - DO a 64 bit build. In this case can a 64 bit build on Ultra Sparc VI work with an existing 32 bit build on a old Sun sparc CPUs.
Thanks in advance for your answers.
Manoj

Answer 1

Hi
Unless your Solaris 8 boxes are really old, then they are probably running the OS 64bit. For instance, we still have a few machines running Solaris 7, like an Ultra 4 that looks like it was installed back in Dec 1999. Even this is running the kernel in 64bit mode.
Having said that, unless you have a pressing need for 64bits (over 3.9G memory requirement typically, maybe a marketing dept that won't take no for an answer), then you're probably better off sticking to 32bits.
You can't mix 32bit and 64bits in a single application. There should be no problem if you want to do socket communication between a 32bit and a 64bit app.
Lastly, you can't compile on a Solaris 9 machine and deploy on a Solaris 8 machine. Backwards compatibility is usually excellent, but forwards compatibility is not assured.
Paul