Forum Discussion
Krzysztof_Kozlo
Nimbostratus
NimbostratusTCP redirect on LB_FAILED for in-band health check.
We have several situations in the enterprise where it is desirable to have a large number of farmed services run on a single pool of servers. New instances come online all the time, and only TCP heal...
Krzysztof_KozloNimbostratus
NimbostratusAccording to the iRules Wiki (which I just discovered, thank you very much):
This command is used to advance to the next available node in a pool, either using the load balancing settings of that pool, or by specifying a member explicitly. ****Note that the reselection is currently limited to two tries.**** (emphasis added)
If this is correct, it means that a loop is not possible, and the logic
when LB_FAILED {
if { [LB::server addr] == "" } {
log "connection failed: no servers available"
} else {
log "connection failed: [LB::server addr]"
LB::reselect
}
}
is all we need. It also means that this technique is limited to pools with three or fewer members (two retries) unless that documentation is obsolete.
