[CentOS] openldap mmr + heartbeat hot standby

Thu May 24 10:38:52 UTC 2012
Wessel van der Aart <wessel at postoffice.nl>


On 05/23/2012 03:39 PM, m.roth at 5-cent.us wrote:
> Wessel van der Aart wrote:
>> Hi List,
>>
>> I've setup 2 openldap servers in n-way multimaster replication mode in a
>> test environment, both run centos 6.2,
>> this works well but now i'm trying to  make these 2 servers failover
>> using heartbeat.
>> i've got no experience with heartbeat (or setting up clusters in
>> general) however from what i understand heartbeat starts/stops the
>> service if the server has the virtual IP assigned or not.
>> this would be fine for httpd , but since replication doesn't work when
>> slapd is stopped i was wondering if anyone knows if there is a way to
>> setup heartbeat with a hot standby? so that the service keeps running
>> but the ip does gets reassigned when one goes down.
> A slight clarification: what happens on a failover cluster is that you've
> got heartbeat running, and each machine looks to see if the other's still
> alive. At this point, one is live, and the other's standby. If/when the
> standby notices it cannot see - even a ping - the other address, or it can
> be configured to look for a service, such as doing a default search (for
> apache, that might be a wget ImAlive.html) - it tells the system to assert
> the IP, and turns up all services for which it's been configured.
>
> I haven't done it, but I'd say you could easily configure heartbeat to
> check, and if the IP's visible, but the service times out, to tell the
> live one to turn down services, and to take over primaryhood.
>
> Hope that's clearer.
>
>          mark
>
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Thanks Mark, that does make it more clear,
i've made a setup and heartbeat does that by default,
when heartbeat shuts down it's stops slapd as well and assignes the ip 
to machine2 and starts slapd there ,
what i want is that it already has slapd running on the failover but 
still checks that service for availability. that way i won't have an 
outdated database on the failover ldap server.
would you know if there is a way of making heartbeat not sending the 
stop command to a particular resource or do i need write a script to 
(not) do this? i wouldn't mind a script but if that function is already 
there  i'd rather use that one.

Thanks, Wessel