[Date Prev][Date Next]
[Chronological]
[Thread]
[Top]
Re: Troubleshooting synchronization
Hi Torsten,
"Torsten Schlabach (Tascel eG)" <tschlabach@tascel.net> writes:
> Hi Dieter!
>
> Your answers are very helpful, thanks for that!
>
>>>> directory design, I wonder if I am suffering from a misconception here,
>>>> i.e. mixing up N-way multi-master and mirror mode possibly.
>>>
>>> probably
>
> So looking at
>
> http://www.openldap.org/doc/admin24/replication.html#Configuring%20the%20different%20replication%20types
>
> What I understand is:
>
> 18.3.1. Syncrepl
>
> This is about the syncrepl engine as such. So this is applicable to all
> types of replication and it's the technical basics, right?
Yes.
> 18.3.2. Delta-syncrepl
>
> I guess this is simple master-slave, isn't it? Though I fail to
> understand why this is about deltas while obviously the other mechanisms
> aren't, are they?
Well, without delta-syncrepl all data of a modified entry is
synchronised. Delta-syncrepl requires a special log database while the
consumer requests information on the modified entries and only
requests the modified attributes.
>
> 18.3.3. N-Way Multi-Master
>
> This was the first section which explained something which sounded like
> what I am looking for. So I went for it.
>
> 18.3.4. MirrorMode
>
> Looking at the config example, I just can't tell the difference to
> 18.3.3. N-Way Multi-Master except:
>
> - samples in this section are not cn=config based, but I guess that
> shouldn't matter but it's just a question of which mechanism I like to
> use, isn't it?
Yes
> - in both N-Way Multi-Master and in Mirror Mode I have serverID,
> mirrormode on and syncrepl statements.
>
> So what actually is the difference between Mirror Mode and N-Way
> Multi-Master except having 2 servers or three servers?
Mirror Mode is just synchronisation between two or more providers,
while only one provider is active (see mirrormode on/off parameter)
and the others are in stand-by mode, consumers only connect to the
active provider.
N-Way Multimaster is a network of active providers which synchronise
data by means of syncrepl. In other words, a client may write to any
of this providers and it is up to the providers to stay synchronised.
Multimaster is not covered by the protocol.
-Dieter
--
Dieter Klünter | Systemberatung
http://dkluenter.de
GPG Key ID:8EF7B6C6
53°37'09,95"N
10°08'02,42"E