LTM config query

Are all the 8 servers (4 primary and 4 secondary) in same pool or different pool if it is different pool, you can achieve it using irule when LB_FAILED { if { [active_members [LB::server pool]] <<= 2 } { Virtual Jurang_pool } else { do nothing }

All these 8 servers are in same pool. Thanks for the reply. Let me configure it and will update you. Thanks!

After 2 Singapore server fail, all traffic must go to the Jurrong or the traffic should be balanced to Singapore AND Jurrong?

You can configure two priority groups.

Singapore priority group as 1 jurang priority group as 2

on pool load balancing method, you have option as priority group activation , you can make it as less than 2 or based on your requirement.

I tried making less than 2 earlier bit it didn't work.

try less than 3. because less than 2 is 1 (not your wanted 2)

Just be carefull when you set priority group, The higher the number, the higher the priority, so a member with a priority of 3 has higher priority than a member with a priority of 1.

So you have to alternative:

Alternative 1: Priority Group Activation less than 1 In this case if you have if you have 2 Singapore servers fails, the load balancin will be done on all other not only jurrong server but the 2 remaining servers.

• singapore-node-1 --> 4 (fails)
• singapore-node-2 --> 4 (fails)
• singapore-node-3 --> 4
• singapore-node-4 --> 4
• jurrong-node-1 --> 3
• jurrong-node-2 --> 3
• jurrong-node-3 --> 3
• jurrong-node-4 --> 3

Alternative 1: Priority Group Activation less than 1 In this case if you have if you have 2 Singapore servers fails, the load balancing will be done only on jurrong server. and if there are problems on the jurong servers the lb will be donne on all availlable server.

• singapore-node-1 --> 4 (fails)
• singapore-node-2 --> 4 (fails)
• singapore-node-3 --> 2
• singapore-node-4 --> 2
• jurrong-node-1 --> 3
• jurrong-node-2 --> 3
• jurrong-node-3 --> 3
• jurrong-node-4 --> 3

For more info:

http://blog.rapidlinksnetworks.co.uk/f5-bigip-priority-group-activation/

Let me know if you need more details.

regards