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Brian_Gibson_30's avatar
Brian_Gibson_30
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Jun 03, 2014

Create multiple node pairs in a pool

I have a request to set up a single pool in which there are multiple cluster pairs inside of the pool.

 

So basically how it works is a user connects to a node. If that node fails the user will fail over to the secondary node for that pair. The key is that there are multiple pairs in the pool so a failover for one node would only failover to the B node of the pair and not the A node of another pair.

 

Can this be done?

 

design

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  • Cory_50405's avatar
    Cory_50405
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    Jun 04, 2014

    If I understand your requirement correctly, it sounds like priority group activation may solve your problem. For example, let's say you have a pool with four members (two pairs) assigned to a specific virtual server. Pair A would be the preferred priority group (with a priority of 5 and 4 assigned to the A members, respectively), and pair B would be the backup priority group (member priority of 3 and 2 respectively).

     

    With this configuration, all requests would be directed to pair A primary member if it's available. If it becomes unavailable, then traffic would fail to pair A secondary member. Failure of both pair A members would mean traffic gets directed to pair B primary member.

     

    http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm-concepts-11-1-0/ltm_pools.html1216212

     

    • Brian_Gibson_30's avatar
      Brian_Gibson_30
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      Jun 25, 2014
      Hi Cory, Thank you for the response. I missed the notification that you responded, thus the long delay in responding. So let's assume we have 2 pairs. Nodes A/B and C/D are the pairs. I want to load balance between A and C. If A fails then I want it to fail to B and if C fails I want it to fail to D. Using Priority group if Node A fails it will fail over to Node B which is not what we are looking to do. Essentially what I need to do is have a group of pools and have the VIP select one of the pools. Each pool would have priority groups inside of it and would have 2 nodes. Perhaps I could use an Irule to do the pool selection. I guess I would just need to figure out how to get the Irule to load balance between pools.
    • Cory_50405's avatar
      Cory_50405
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      Jun 25, 2014
      I think you're on the right track. Once you have it figured out, please come back and post your final iRule if you don't mind. Someone in the community may benefit from it.