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Forum Discussion

ldesfosses's avatar
ldesfosses
Icon for Cirrus rankCirrus
Apr 09, 2020

Sync config in an Active/Active cluster.

Hi,

 

I've an Active/Active cluster and for an unknown reason, I can't Sync the config.

When I do a change on one of the LTM , nothing happen.

 

I've created the "Device Group" and added the two device in, I've set it to "Manual with Full Sync".

 

Even after a change, the device status stay "In Sync".

BIG-IP
cloud
LTM
sync

7 Replies

  • ldesfosses's avatar
    ldesfosses
    Icon for Cirrus rankCirrus
    Apr 09, 2020

    This is the config of the device group (AWS VM, v14.1.2) : 

    cm device-group dg-Sync {
    devices {
        device1 { }
        device2 { }
    }
    full-load-on-sync true
    network-failover disabled
}

    If I activate the failover, the problem is not present. It's not possible to sync active/active cluster ?

  • Mayur_Sutare's avatar
    Mayur_Sutare
    Icon for MVP rankMVP
    Apr 10, 2020

      When you are making any changes on any of the node/unit, do you see those changes on the other node? I think you will as you said, it stays "in sync". It seems config is getting sync automatically. Can you please put snap for Device group config for both units?

    One question here, why network-failover is in disabled state?

     

    Mayur

    • ldesfosses's avatar
      ldesfosses
      Icon for Cirrus rankCirrus
      Apr 10, 2020

      No, that's the problem, I don't see my change replicated.

      And a 

      tail -f /var/log/ltm

      doesn't show the traffic group message, like it does on my active/passive cluster.

      The cluster device are set on the same NTP, so time is not an issue here.

      • Mayur_Sutare's avatar
        Mayur_Sutare
        Icon for MVP rankMVP
        Apr 11, 2020

        Do you see any logs related to config sync under 'tail -f /var/log/ltm' ? Please see those logs which may give more clarity on this.

         

        Also why you have Network Failover in disabled state?

         

        Mayur

  • Shanley's avatar
    Shanley
    Icon for Nimbostratus rankNimbostratus
    Apr 11, 2020

    Alternatively however, you can create a second traffic group and activate that traffic group on a peer device. In this active-active configuration, the devices each process traffic for a different application simultaneously WalgreensListens. If one of the devices in the device group goes offline, the traffic group that was active on that device fails over to a peer device.

    • ldesfosses's avatar
      ldesfosses
      Icon for Cirrus rankCirrus
      Apr 11, 2020

      You mean having some VIP on a traffic group and other VIP on another traffic group ?

       

      Here, the need is to have active/active, because the traffic come from different place around the world, via BGP the same IP is announced on multiple link. Depending on your location (no, GTM/DNS is not a solution here), you'll hit one VIP or another.

  • Mayur_Sutare's avatar
    Mayur_Sutare
    Icon for MVP rankMVP
    Apr 13, 2020

    As you already have ACTIVE-ACTIVE setup, you are having two traffic groups. One traffic group is active on one F5 node and 2nd group on other. So whatever is explained by @Shanley, it should be already configured in your setup.

     

    Mayur