Problems with keepalived

[Sébastien BONNET]

Brad Dameron a écrit :
> On Wed, 2006-06-28 at 10:22 +0100, Dr A V Le Blanc wrote:
>> For many years we have used keepalived to manage our lvs farm,
>> but I have never managed to get it to failover automatically,
>> so I've simply used manual failover.  I have tried a large number
>> of minor variations on configuration files, but let me give a
>> simple example.  There are two directors.  One has this in its
>> /etc/keepalived/keepalived.conf file:
>>
>> vrrp_sync_group VG1 {
>>   group {
>>     VI_1
>>   }
>> }
>>
>> vrrp_instance VI_1 {
>>     state MASTER
>>     interface eth0
>>     virtual_router_id 51
>>     priority 150
>>     authentication {
>>         auth_type PASS
>>         auth_pass 1111
>>     }
>>     virtual_ipaddress {
>>         130.88.203.138
>>         130.88.203.219
>>     }
>> }
>>
>> and the other has this:
>>
>> vrrp_sync_group VG1 {
>>   group {
>>     VI_1
>>   }
>> }
>>
>> vrrp_instance VI_1 {
>>     state BACKUP
>>     interface eth0
>>     virtual_router_id 51
>>     priority 50
>>     authentication {
>>         auth_type PASS
>>         auth_pass 1111
>>     }
>>     virtual_ipaddress {
>>         130.88.203.138
>>         130.88.203.219
>>     }
>> }
>>
> 
> Your virtual_router_id on the backup needs to be incremented. 

I don't agree with that. From keepalived.conf man page :

virtual_router_id is used to differentiate multiple instances of vrrpd 
running on the same NIC

I'd rather replace NIC by network.

This means that, across a given network, each VRRP instance should have 
its own/unique virtual_router_id.

But, as there is no "master VRRP instances" nor "backup VRRP instances" 
but "virtual instances in master or backup state", all servers hosting 
the same VRRP instance should have the same virtual_router_id for that 
instance.

If you have a simple symmetric cluster, your conf file should be the 
same on both servers, except for the following keywords in 
vrrp_instance: state, priority, nopreempt and interface.

-- 
Sébastien BONNET     --    Ingénieur système
Tel: 04.42.25.15.40      GSM: 06.64.44.58.98