Improving mod_perl Driven Site's Performance -- Part I: Choosing Operating System and Hardware Page 8
It may happen that the combination of software components which you find yourself using gives rise to conflicting requirements for the optimization of tuning parameters. If you can separate the components onto different machines you may find that this approach (a kind of clustering) solves the problem, at much less cost than buying faster hardware, because you can tune the machines individually to suit the tasks they should perform.
For example if you need to run a relational database engine and mod_perl server, it can be wise to put the two on different machines, since while RDBMS need a very fast disk, mod_perl processes need lots of memory. So by placing the two on different machines it's easy to optimize each machine separately and satisfy each software components' requirements in the best way.
The mod_perl site's URL: http://perl.apache.org
For more information about RAID see the Disk-HOWTO, Module-HOWTO and
Parallel-Processing-HOWTO available from the Linux Documentation
Project and its mirrors (http://www.linuxdoc.org/docs.html#howto)
For more information about clusters and high availability setups, see:
High-Availability Linux Project -- the definitive guide to load balancing techniques (http://www.henge.com/~alanr/ha/)
Linux Virtual Server Project (http://www.linuxvirtualserver.org/)
mod_backhand -- Load Balancing for Apache (http://www.backhand.org/mod_backhand/)
mod_redundancy -- Redundancy/Failover solution (http://www.ask-the-guru.com)
lbnamed - a Load Balancing Name Server Written in Perl (http://www.stanford.edu/~riepel/lbnamed/ http://www.stanford.edu/~riepel/lbnamed/bof.talk/ http://www.stanford.edu/~schemers/docs/lbnamed/lbnamed.html)