real server failure recovery

jlhainy · ‎01-06-2009

I have 2 web servers that I am load balanncing. Is there a way to set up an automatic out of service so that if the real server goes down, the load balancer will automatically not balance to the downed server. What is happening is that apache is dying on one of the servers and I would like to set it up so if apache dies, the cms will know not to load balance to that server.

Collin Clark · ‎01-06-2009

You can create TCP/ICMP/URL/COOKIE/ETC probes to your servers. If it fails, the server is automatically removed from the farm. When it comes back up, it's automatically added back to the farm. Check the config guide (look for probe or I can post my config if it will help.

jlhainy · ‎01-06-2009

Thanks, I will look into that. If you still don't mind posting your config, it would be nice to see a real world example.

Collin Clark · ‎01-07-2009

Sure, here you go.

I have two WWW servers; 192.168.1.1 & 192.168.1.2

probe tcp TCP_Connect_to_WWW-1

description TCP_Connect_to_WWW-1

ip address 192.168.1.1

interval 3

passdetect interval 3

passdetect count 10

open 2

probe tcp TCP_Connect_to_WWW-2

description TCP_Connect_to_WWW-2

ip address 192.168.1.2

interval 3

passdetect interval 3

passdetect count 10

open 2

rserver host WWW_1

ip address 172.16.210.1

conn-limit max 4000000 min 4000000

probe TCP_Connect_to_WWW-1

inservice

rserver host WWW_2

ip address 172.16.210.2

conn-limit max 4000000 min 4000000

probe TCP_Connect_to_WWW-2

inservice