Set Up F5 load balancer for BRM (Oracle Communications Billing and Revenue Management MAA on Oracle Engineered Systems) CMMP Traffic

Here is the iRule in a more readable (I hope) form:

 brm
-
iRule 
when CLIENT_ACCEPTED {
 The current pool is derived from the virtual server's "Default Pool"
set current_pool [LB::server pool]
 Count of reselect attempts
set reselects 0
}
when LB_FAILED {
 Reselect another pool member if the connection fails.  
 Limit reselects to the number of active members.
 To be active, a member must be enabled with status available or 
 unknown.
if { $reselects < [active_members $current_pool] } {
incr reselects
log local0.info "Client [IP::client_addr]:[TCP::client_port]: Selected 
pool member [LB::server addr]:[LB::server port] not responding.  Reselect 
attempt $reselects."
LB::mode rr
LB::reselect pool $current_pool
} else {
log local0.error "Client [IP::client_addr]:[TCP::client_port]: Failed 
to connect after $reselects reselects."
}
}

Basically if the connection to the pool member fails this irule causes the BigIP to go back and pick a new pool member. It keeps this up (Logging each failure) until it has tried each pool member, at which point it logs that it could not make the connection. As to why it's needed, that would be an excellent question to ask Oracle.

From the Oracle article linked to above, Oracle stipulates the use of "tcp-half-open" for the health monitor at the default polling frequency, which is really not a stringent measurement of the state of an application. I guess this irule is there simply for logging the F5 device's operation in more detail, as presumably befits the requirement of an application that is monetary in nature.