I’ve spent the last week or so writing a customer emulation script for the QA group here to test some of our archiving products. If you’re unfamiliar with PHFOS/CIOSim, take a look here. In short, PHFOS/CIOSim is a small multi-threaded program that randomly selects files in a given directory to open and hold open.

I started out writing the script in Perl, which at this point is the scripting language I know the best, I then decided that now is as good a time as any to learn Ruby (which I’ve been interested in for a while now), so I re-wrote the entire program in Ruby (first *useful* script I’ve actually written in Ruby). Then, one day at work I was told that I needed to extend the program to support 5000 simultaneous threads doing disk I/O. I thought about this for a while and (after talking with my friend Jon about it) decided on using Java, as the threading was much more robust (something I had problems with using Ruby and Perl). Well, I’ve got working versions of all 3 programs and I thought I’d share my perspective on the pro’s and con’s of each one:

Java pro’s:

• Most robust thread implementation of the 3 languages
• Handles SMP much better than ruby
• Code is portable with minimum requirements to run
• OO language (a bigger pro to actual developers who this matters more to)

Java con’s:

• JVM overhead (not really that much nowadays)
• More difficult to read due to Java’s extreme verbosity
• Requires jdk 1.5+ (1.4 is still the only actual “supported” JDK in my company)

Ruby pro’s:

• Most readable code of all 3 (shortest too)
• I got to learn Ruby
• Ruby implementation available for most platforms
• More OO than Perl (not that I used OO…)

Ruby con’s:

• Ruby only took advantage of 1 of my CPU cores (Java used both)
• Ruby is slower than Perl (maybe one day they’ll be just as fast?)
• Almost no one in my department has heard of Ruby

Perl pro’s:

• Super-easy to install with ActiveState for windows, comes default with most *nix
• Super-easy to install the required module: perl -MCPAN -e shell ; install File::Random
• Allows fine-grain tuning of thread parameters (adjustable thread stack size)

Perl con’s:

• If you don’t have threaded perl, gotta reinstall (/cry @ Solaris)
• Least readable code (unless you loooovvve punctuation)
• Perl doesn’t like me spawning millions of threads and detaching all of them

Overall, since I need code that’s portable to multiple platforms easily, while allowing for very large amounts of IO, I’ll probably stick to the java version (which was renamed CIOSim [Customer I/O Simulator] because you actually pronounce it :P), followed by the Ruby version (so easy to write), and then the Perl version, which, actually has the largest amount of features.

I haven’t written all the features into each version yet (except for the Perl one), but, if you’d like to take a look at them, here they are:

Java version
Ruby version
Perl version

Next tool I need to write, I’ll probably be looking at Ruby

Anyone out there use anything different for sysadmin tools? Python? Lisp? Assembler? Leave a comment and let me know