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On Tuesday 22 July 2008 10:41:18 Liutauras Adomaitis wrote:
On Tue, Jul 22, 2008 at 10:02 AM, Buchan Milne bgmilne@staff.telkomsa.net
wrote:
On Monday 21 July 2008 14:48:23 Liutauras Adomaitis wrote:
On Mon, Jul 21, 2008 at 12:49 PM, Buchan Milne <
bgmilne@staff.telkomsa.net>
wrote:
On Sunday 20 July 2008 23:34:03 Liutauras Adomaitis wrote:
[...]
It shows, that it is adding MirrorMode TRUE. So why?
The configuration directive may have been overloaded when multi-master was added (after mirrormode). AFAIK it allows the database in question
to
both have a syncrepl directive, yet take updates from a DN besides the updatedn (see the description on the slapd.conf man page).
are you saying, that in multimaster configuration I have to have updatedn directive to be able to do writes?
No. Without mirrormode or multi-master, a slave would only accept updates from the updatedn. In multi-master, the master is also a slave, so it needs to accept updates from any DN, while being configured as a slave (having replication configuration).
Sorry, but still don't get it. As you say node in multimaster configuration is master and slave at the same time. As a slave it can accept writes only having updatedn directive. Right? I'm really sorry if I don't understand, but it seems that "No" contradicts other sentences.
No means: your interpretation that it is multimaster requires updatedn to be set is incorrect.
In thread "explain diff between multimaster and mirror mode" I found out, that mirrormode is kind of high availability implementation for openldap. In my case I want to have multimaster replication, which could allow me
to
do writes to different master servers at a time.
You may want to think very carefully about why you want this, and not mirrormode, or a single master.
Yes maybe it is not necessary. I have read some posts saying the same - people do multimaster then they really don't need it at all. This is my first acquaintance with syncrepl and ldap replication, so I don't really know what is best for me. I tried master- slave, but it had some undisired side effects,
If you are that unspecific about the issues, we can't comment on your decision.
so I decided to switch to configuration there I could do writes on "slaves", and turned those slaves into masters. I didn't know about updatedn directive which maybe is suitable for me, but needs to be tested. I decided not to do mirrormode, because according to Dieter Kluenter: "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" But I need to do writes at both master at the same tme.
You haven't explained why, so we can't give you feedback on your decision to use multimaster.
Are you sure it is not some other aspect of your configuration? Have you posted details? Have you posted the error message?
The most probably it is my configuration and I'm missing something. The error is "shadow context; no update referral at ...", I have posted in my first letter. I receive this error on any master I try to do writes. If add mirrormode true to the end - I can do writes.
Exactly. Enabling "mirrormode" is a prerequisite for multimaster.
The difference between mirrormode an multimaster (as far as I know) these days (post 2.4.6) is really your architecture (whether you allow writes to one master, or more), not the configuration (though more than two syncrepl statements does mean that it can't be mirrormode).
I have one central master, and other master are replicated from this one.
This is not the definition of multimaster. As far as I know, the recommended architecture for multimaster is that all masters can see (replicate from) each other. Otherwise, they are locally writable slaves, with no guarantee of convergence.
Configuration of other masters are the same, except serverID are 2 and 3 respectively and they have only one syncrepl directive pointing to central master. So there is no replication between master002 and master 001.
Regards, Buchan