On Sat, Jul 19, 2008 at 11:19 AM, Dieter Kluenter dieter@dkluenter.de wrote:
Hi,
"Liutauras Adomaitis" liutauras.adomaitis@gmail.com writes:
Hello,
I feel a little bit spaming this list, but still - how to setup
multi-master?
Reading http://www.zytrax.com/books/ldap/ch7/#ol-syncrepl http://www.openldap.org/doc/admin24/replication.html gave me impression that simply adding serverID in global (above database) section, syncrepl and overlay syncprov in database section should give me multi master setup. THis did worked - meaning I got the same data on both servers, but I couldn't make updates to either of servers. Google says absolutely nothing about that. The error is "shadow context; no update referral at ..." Adding updateref directive to conf file seemed to me
wrong,
because multi master is meant to be multi write nodes setup, so I didn't
tried
that. After about four hours of searching for any full working example of multi-master implementation I decided to put mirror mode true on both
servers
at the end of conf file - that did the trick. So do I need add mirror mode or not? It is not clear the difference of multi-master and mirror mode, which I asked on different message. I didn't tried setting mirror mode false and see if updates are working,
but
if this is what I missed, then it is very strange, that official administrators guide is missing such a key point.
Multi-way replication and mirror mode are two different aproaches. While ldap servers configured for n-way replication are all visible and available by all clients and all allowing all operations. Mirror mode is a sort of backup and standby system. Only one ldap server should be visible and available, thus allowing write operations, while the second ldap-server is in hot standby position, and only available to clients if the first server fails. Run test050 to get simple configuration examples for n-way replication. For mirror mode configuration see http://www.openldap.org/doc/admin24/replication.html, part 17.3.2 and 17.4.4
Your explanation has answered the other my question "difference between multi master and mirror mode".
I was always using Mandriva rpms and never compiled openldap by myself. But few days ago I did compiling of openldap srpm and saw it doing some tests. I'm going to dig arround for how to make this test050 on Mandriva.
Thanks a lot Liutauras