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Re: Troubleshooting synchronization
"Torsten Schlabach (Tascel eG)" <email@example.com> 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.
> So looking at
> 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?
> 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?
> - 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
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 Klünter | Systemberatung
GPG Key ID:8EF7B6C6