Perl compatibility

Question

This isn't my area of expertise so I'm asking hopefully the right question.

We have a server that is lease rolling. The old server is a 32-bit windows server and the new server is 64-bit windows 2008 R2 SP1.

One of the web applications uses Perl to run some scripts.

1. We can run the same 32bit version on the new 64-bit machine? (e.g. if there is a same version but one is 32-bit and one is 64-bit, are they essentially the same?)
2. If a script is working on a 32-bit version, should it still work under the 64-bit version of Perl?

If the questions need clarifying, please let me know and I'll see about asking the appropriate person on our team.

Answer 1

If you're concerned about compatibility, you should be able to run the 32-bit version of perl on the 64-bit machine (assuming both are x86). But the 64-bit version should work more or less the same as the 32-bit one, with a couple of exceptions that should not affect scripts. (They have to do with C/XS code in modules, mostly. Binary-compatibility stuff. Meaning modules will have to be built for 64-bit. Fortunately, any Perl interpreter that doesn't suck will do the build stuff for you in the case of *nix, or provide a package manager that has pre-built modules like ActiveState does.)

Answer 2

1. Yes, you can, as long as you redeploy properly, including the build steps for dependencies. Just copying files over will only work if the whole application stack is pure-Perl, which is not likely. — Yes, they are essentially the same, but binary incompatible.
2. Likely yes. Problems can arise with the dependencies, however the number of modules that fail due to 32-bit/64-bit differences are miniscule.

Answer 3

I think the answers to both your questions are yes. The 32-bit applications should run fine on your 64-bit Windows, but will not be able to utilize any of the 64-bit features (where a larger usable address space may very well be the most important if you ever want to parse big XML using XML::Twig ;-).

The script running under 32-bit perl will work on a 64-bit perl, provided you get all the modules for the 64-bit perl in order, since they typically run from different directories. Also, be aware that for 64-bit perl on Windows you probably need Strawberry perl, ActiveState perl or similar. Cygwin is only 32-bit as far as I know.