actually, rlimit not "load balancing". it just restrict "resource usage". as "load balancing" usually mean distributed services runned on one-two-or-more servers. i.e. requests to apache can be distributed to few servers instead only one. servers can be VPS and as result hosted on one machine but as minimum you need few runned apache.
for example if you have simple apache load balanced solution like above you can increase maximum value of runned apache processes from 150 (default value for apache MaxClient) to 150*x where x mean different apache copies.
It is also mean that you can run multiply apache on one server but you will need use also some proxy server (like squid) and assign each apache server to dedicated ip or dedicated port. you need proxy for setting "load balancer".
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