download the binaries from
http://search.cpan.org/dist/Perlbal/
standard perl module prerequisites include:
Danga::Socket
Sys::Syscall
IO::AIO
find these with
sudo apt-cache search socket | grep danga
(and just) install these with
sudo apt-get install libdanga-socket-perl
sudo apt-get install libsys-syscall-perl
sudo apt-get install libio-aio-perl
untar the downloaded file and run
sudo perl Makefile.PL
make
make test
make install
sudo mkdir /etc/perlbal
copy the conf file from http://www.livejournal.com/doc/server/lj.install.supplemental_sw.perlbal.html
into /etc/perlbal/perlbal.conf (this is where perlbal looks by default for its conf file)
make sure that Apache or any other daemon isn’t already bound to port 80. Assign a different port, like 8080 to apache if its running on the same system.