Up to Speed with VelociGen
PRODUCT:
VelociGen for Perl 2.0
By Brian Wilson
Web sites often rely heavily on an installed base of Perl scripts, which have long been a favorite for processing input from forms. Such scripts are also widely employed to generate HTML pages on the fly. Unfortunately, methods used to invoke Perl scripts can dramatically impact server performance.
Typically, invoking scripts involves using either common gateway interface (CGI) or server side includes (SSI). Because both are general-purpose approaches, they work by sending a call to the operating system with the name of the program to be executed. The executable can be any runnable program or script, written in any language.
The problem with this approach is that it requires a lot of system overhead because the executable must be loaded for each invocation. When the executable is a Perl script, Perl must also be loaded so that it can interpret and execute the script. That's where Perl accelerators—like VelociGen from Binary Evolution, and mod_perl, an open-source project integrated with the Apache Web server—come in.
VelociGen for Perl is a script accelerator that loads a Perl engine into memory when launched. The engine can communicate directly with the Web server to load and execute scripts. This cuts out the biggest bottleneck, the load time for the Perl interpreter. VelociGen also can be configured to keep scripts cached so that even overhead from reading the script file is reduced.
