Forum Discussion
damon_schott_19
Nimbostratus
NimbostratusPin down a 1 to 1 mappping after node failure.
I currently have the following iRule that pins down load balancing decisions in a 1 to 1 mapping based on source address, this works great except for when there is a failure on any 1 of the port 17000 nodes. There is a persistency requirement that breaks when any 1 of these nodes fail. I am looking for a way to expand on this iRule to basically say "if LB::status pool = "down", then go to the next available node in the pool (meanwhile keeping persistent until the original node comes back online)
when CLIENT_ACCEPTED {
if {[IP::addr [IP::remote_addr] equals 172.17.168.230/32] }{
if { [LB::status pool [LB::server pool] member 172.17.168.212 17000 ] == "up" }
pool [LB::server pool] member 172.17.168.212 17000
}
}
elseif {[IP::addr [IP::remote_addr] equals 172.17.168.231/32] }{
if { [LB::status pool [LB::server pool] member 172.17.168.213 17000 ] == "up" }
pool [LB::server pool] member 172.17.168.213 17000
}
}
elseif {[IP::addr [IP::remote_addr] equals 172.17.168.232/32] }{
if { [LB::status pool [LB::server pool] member 172.17.168.214 17000 ] == "up" }
pool [LB::server pool] member 172.17.168.214 17000
}
}
}
- The_BhattmanHi Damon,
Is this what you were looking for?when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 172.17.168.230/32] }{ if { [LB::status pool [LB::server pool] member 172.17.168.212 17000 ] == "up" } pool [LB::server pool] member 172.17.168.212 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.213 17000 ] == "up" } pool [LB::server pool] member 172.17.168.213 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.214 17000 ] == "up" } pool [LB::server pool] member 172.17.168.214 17000 } } elseif {[IP::addr [IP::remote_addr] equals 172.17.168.231/32] }{ if { [LB::status pool [LB::server pool] member 172.17.168.213 17000 ] == "up" } pool [LB::server pool] member 172.17.168.213 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.214 17000 ] == "up" } pool [LB::server pool] member 172.17.168.214 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.212 17000 ] == "up" } pool [LB::server pool] member 172.17.168.212 17000 } } elseif {[IP::addr [IP::remote_addr] equals 172.17.168.232/32] }{ if { [LB::status pool [LB::server pool] member 172.17.168.214 17000 ] == "up" } pool [LB::server pool] member 172.17.168.214 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.212 17000 ] == "up" } pool [LB::server pool] member 172.17.168.212 17000 } elseif { [LB::status pool [LB::server pool] member 172.17.168.213 17000 ] == "up" } pool [LB::server pool] member 172.17.168.213 17000 } } }
Bhattman 
damon_schott_19Thanks Bhattman, I think that IS what I was looking for; I applied this update to the VIP and will perform the testing. Thanks again.
Damon- The_BhattmanHi Damon,
I was thinking that perhaps there must be an easier way to accomplish what you are doing while reducing the amount of code in the irule.
Another approach is to use priority load balancing.
You could create 3 pools
Pool_230 would contain
172.17.168.212:17000 with priority 100 <== Active
172.17.168.213:17000 with priority 50 <== Inactive
172.17.168.214:17000 with priority 25 <== Active
With minimum active member is 1.
Pool_231 would contain
172.17.168.212:17000 with priority 25 <== Inactive
172.17.168.213:17000 with priority 100 <== Active
172.17.168.214:17000 with priority 50 <== Inactive
With minimum active member is 1.
Pool_233 would contain
172.17.168.212:17000 with priority 25 <== Inactive
172.17.168.213:17000 with priority 50 <== Inactive
172.17.168.214:17000 with priority 100 <== Active
With minimum active member is 1.
With priority load balancing only 1 member is active at any time - until there is a failure, then next priority takes over
Then your irule could be shorted to the following:when CLIENT_ACCEPTED { if {[IP::addr [IP::remote_addr] equals 172.17.168.230/32] }{ pool pool_230 } elseif {[IP::addr [IP::remote_addr] equals 172.17.168.231/32] }{ pool pool_231 } elseif {[IP::addr [IP::remote_addr] equals 172.17.168.232/32] }{ pool pool_232 } }
I hope this helps
Bhattman - damon_schott_19Bhattman, thank you, that is terrific. I will certainly give that a try. Thanks again for all your assistance
