Hello. I need to make high availability failover solution with F5 and I can't find the way how to do it - VIP holding certificate and pool with two identical nodes, which act as high availability, not load sharing etc as the problem is, that both nodes are running one specific application, and only one application in one server can be in live. So if the first node goes down, all the traffic will be switched to the second node and if later the fist node come available, still the second node holds active connections and also gets all new connections, until it goes down and all the traffic will be switched to the first node, and so on? Is this possible with F5, using latest 9.4.5 HF 2?

Yep. Deb posted a nice example of this in the iRules codeshare: Single Node Persistence (Click here) Aaron

Yep. Deb posted a nice example of this in the iRules codeshare: Single Node Persistence (Click here) Great tip, thank You.

Yep. Deb posted a nice example of this in the iRules codeshare: Single Node Persistence (Click here) Well, just tried, but I'm getting an error, when trying to save this iRule: 01070151:3: Rule [single_node_persistence] error: line 1: [undefined procedure: rule] [rule PriorityFailover { when CLIENT_ACCEPTED { persist uie 1 } }]

The "rule PriorityFailover {" is for the configuration file. If you are trying to save the rule in the GUI or the Editor just include the "when" pieces. when CLIENT_ACCEPTED { persist uie 1 } -Joe

The "rule PriorityFailover {" is for the configuration file. If you are trying to save the rule in the GUI or the Editor just include the "when" pieces. when CLIENT_ACCEPTED { persist uie 1 } Thank You!

F5 as high availability failover and not as load sharing?

12 Replies

hooleylist
Cirrostratus
Oct 06, 2008
Yep. Deb posted a nice example of this in the iRules codeshare:

Single Node Persistence (Click here)

Aaron
mart_58302
Nimbostratus
Oct 08, 2008

Yep. Deb posted a nice example of this in the iRules codeshare:

Single Node Persistence (Click here)

Great tip, thank You.
mart_58302
Nimbostratus
Oct 10, 2008

Yep. Deb posted a nice example of this in the iRules codeshare:

Single Node Persistence (Click here)

Well, just tried, but I'm getting an error, when trying to save this iRule:

01070151:3: Rule [single_node_persistence] error: line 1: [undefined procedure: rule] [rule PriorityFailover { when CLIENT_ACCEPTED { persist uie 1 } }]
Joe_Pruitt
Oct 10, 2008
The "rule PriorityFailover {" is for the configuration file. If you are trying to save the rule in the GUI or the Editor just include the "when" pieces.

when CLIENT_ACCEPTED { persist uie 1 }

-Joe
mart_58302
Nimbostratus
Oct 11, 2008

The "rule PriorityFailover {" is for the configuration file. If you are trying to save the rule in the GUI or the Editor just include the "when" pieces.

when CLIENT_ACCEPTED { persist uie 1 }

Thank You!
JRahm
Admin
Oct 13, 2008
If entering in the GUI, this is all you need, as the rule { } is wrapped around the argument for inclusion in the CLI (masked in the GUI):

when CLIENT_ACCEPTED { persist uie 1 }
JRahm
Admin
Oct 13, 2008
Disregard...missed Joe's response
mart_58302
Nimbostratus
Oct 14, 2008

when CLIENT_ACCEPTED { persist uie 1 }

Ok, iRule is done, but one if I'm using this iRule, what should I set up in pool > Members > Load Balancing Method? Or it doesn't matter what there is as iRule takes control before it?
hooleylist
Cirrostratus
Oct 14, 2008
Hi Mart,

The load balancing algorithm will only affect which pool member is chosen first. Once a single request has been answered by the first selected pool member, all requests will go to that member for as long as it is marked up by the monitor. If you want to try to force one pool member to be selected first, you could use priority on the pool. But this is still independent of the load balancing algorithm. I'd suggest round robin would be fine.

Aaron
mart_58302
Nimbostratus
Oct 14, 2008

The load balancing algorithm will only affect which pool member is chosen first. Once a single request has been answered by the first selected pool member, all requests will go to that member for as long as it is marked up by the monitor. If you want to try to force one pool member to be selected first, you could use priority on the pool. But this is still independent of the load balancing algorithm. I'd suggest round robin would be fine.

Great, I'll leave the round robin then.