This is a large production environment (several hundred servers,
thousands of requests per minute) and the F5-LB is used to balance the
load and take care if a node needs to be taken out of service for maint
for any reason. With RR DNS if a server is slow (for whatever reason
,backups ,etc) the F5 notices that and adjusts the connections
distribution as needed, RR DNS can't do that. As far as indexes, the
environment has been performing extremelywell until recently after a
few m=hundred thousand more users were added as well as signifiantly
higher activity, at which point we began seeing issues when behind the
loadbalancers during peak times of day. The LB vender says the issue
is with with openldap, and those settings,
conn_max_pending/conn_max_pending_auth were the only ones that seemed
to stick out, though the documentation on those is rather ambiguous.