"Now starting from a working Apache installation, what can Lighttpd offer us?
"* Improved performance for most cases (as in more hits per second)
* Reduced CPU time and memory usage
* Improved security
"Of course, the move to Lighttpd is not a small one, especially if our Apache configuration makes use of its many features. Systems tied into Apache as a module may make the move hard or even impossible without porting the module to a Lighttpd module or moving the functionality into CGI programs, if possible.
"We can ease the pain by moving in small steps. The following descriptions assume that we have one Apache instance running on one hardware instance. But we can scale the method by repeating it for every hardware instance.
"When not to migrate
"Before we start this journey, we need to know that our hardware and operating systems support Lighttpd, that we have root access (or access to someone who has), and that the system has enough space for another Lighttpd installation (yes, I know, Lighttpd should reduce space concerns, but I have seen Apache installations munching away entire RAID arrays). Probably, this only makes sense if we plan on moving a big percentage of traffic to Lighttpd. We also might make extensive use of Apache module, which means a complete migration would involve finding or writing suitable substitutes for Lighttpd."
