1

I have 2 nodes with Keepalived v1.2.13, in Amazon AWS VPC.

I'm trying to achieve this scenario, assuming Node1 is MASTER:
If I stop HAProxy or stop keepalived or stop the node, failover to Node2.
If I start HAProxy back up on Node1 or start keepalived or start the node, do not failover to Node1 (no flapping).

With the following configuration, only by stopping keepalived or stopping the node, does the failover works. The priority change due to the track_script doesn't seem to affect the MASTER election.

Node1

vrrp_script chk_haproxy {       # Requires keepalived-1.1.13
script "killall -0 haproxy"     # cheaper than pidof
interval 2                      # check every 2 seconds
fall 2
weight 2                        # add 2 points of prio if OK
}

vrrp_instance VI_1 {
    advert_int 2
    state BACKUP
    nopreempt
    interface eth0
    virtual_router_id 51
    priority 101
    unicast_peer {
        172.17.16.10
    }

    notify_master "/etc/keepalived/randomscript.sh"
    track_script {
        chk_haproxy
    }
}

Node2

vrrp_script chk_haproxy {       # Requires keepalived-1.1.13
script "killall -0 haproxy"     # cheaper than pidof
interval 2                      # check every 2 seconds
fall 2
weight 2                        # add 2 points of prio if OK
}

vrrp_instance VI_1 {
    advert_int 2
    state BACKUP
    nopreempt
    interface eth0
    virtual_router_id 51
    priority 100
    unicast_peer {
        172.17.16.11
    }

    notify_master "/etc/keepalived/randomscript.sh"
    track_script {
        chk_haproxy
    }
}
Bastien974
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  • I also tried on both nodes : state EQUAL, priority 100. This cause a race condition when both instances are booting at the same time, both transition to MASTER, execute the randomscript.sh, and 4-5 seconds after that one node transition to BACKUP, but I don't want the script to be executed. – Bastien974 Apr 23 '15 at 12:52
  • migrate your cluster to pacemaker – c4f4t0r Jan 08 '19 at 12:34

1 Answers1

1

I ended up using on both nodes : 

state EQUAL
priority 100

The race condition was due to some kind of issue with the security group of the instances. So this is an issue specific to AWS.

For an unknown reason, VRRP Unicast works even though not explicitly allowed in the security group. I explicitly opened it (Custom Protocol 112) and it fixed the issue. It seems like it takes time to allow the packet during the initialization of a stack.

Bastien974
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