Workload management is critically important for an on-demand business. IBM LoadLeveler is a job-management system that allows users to run more jobs in less time by matching the jobs’ processing needs with the available resources. Maintaining maximum system uptime of the job management system is increasingly important.
Mainframe Batch Processing comes to linux a whole new generation of batch process loading monkey’s are born!
Also take a look at:
http://linux-vserver.org/
http://www.keepalived.org/
http://www.ultramonkey.org/
http://linux-ha.org/
Rather then VRRP (which is encumbered with Cisco patents…)
http://www.ucarp.org/
And for webserver fail-over (and reverse-proxying)
http://www.apsis.ch/pound/