Re: Mirror Mode, replicas and delta-syncrepl

[Sam Tran <stlist@gmail.com>]

On Thu, Oct 22, 2009 at 6:47 PM, Quanah Gibson-Mount <quanah@zimbra.com> wrote:
> --On Thursday, October 22, 2009 4:34 PM -0400 Sam Tran <stlist@gmail.com>
> wrote:
>
>> Hi All,
>>
>> I am looking to upgrade our OL 2.3 platform to OL 2.4.
>>
>> For all write operations, I'd like to have two masters in Mirror Mode
>> configuration and behind a load balancer with a virtual IP (VIP)
>> address. All read operations will be performed on a set of replicas.
>> The replication mode would be delta-syncrepl. I am trying to figure
>> out how to configure replication between the replicas and the masters.
>> I came across those two threads that seem to address this issue:
>>
>> http://www.openldap.org/lists/openldap-devel/200903/msg00085.html
>> http://www.openldap.org/lists/openldap-software/200903/msg00127.html
>>
>> If I understand correctly, there are two possible configurations:
>>
>> 1) On each replica, create a single syncrepl stanza that points to the
>> load balancer VIP.
>>
>> 2) On each replica, creates two syncrepl stanzas, each one pointing to
>> a different master.
>>
>> Could you please confirm that both configurations would work? Should
>> the second configuration be favored over the first for it does not
>> depend on the load balancer?
>
> I don't know the answer, but let me know when you figure it out. ;)  I'd
> guess the first option would be best, since only one master will be
> receiving the writes as well, since you'll be using mirror mode.
>

I was planning to use the load balancer in the 2nd configuration as
well. In both cases only a single master will receive the write
requests. The 2nd configuration would still work in the event of a
failure of the load balancer.