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Re: n-way replication question

Holger Kaelberer <Holger.Kaelberer@telefonica.de> writes:

> Hi,
> Dieter Kluenter wrote:
>>> What is your configuration on all servers?  In detail, what's the
>>> value of the serverID statements, of the syncrepl statements and
>>> what's the URI you're running them with?
>> Solved it, silly me!
>> The initial slapd.conf should only contain one serverID statement
>> without any additional address, only after starting all peers the
>> serverID has to be modified to include all participating peers.
> seems that I had exactly the same problem when setting up
> multimaster-repl. By trial and error I solved it by only defining one
> serverID on each host:
> # master1
> serverID 1
> # master2
> serverID 2
> With this setting multimaster-repl seems to work correctly.
> As I don't understand exactly how this statement affects
> multimaster-replication my question is, whether it is ok to do so or
> do I *need* to define all serverID as
> serverID NUM URL
> on all participating master.

If one thinks about it, it is obvious that each participating peer has
to be informed about its sid, as other peers are not participating
prior to the initial setup, its only one sid.
After starting all peers, they have to be informed about all
particiating sids, that is prior to adding any data the sids have to
be anounced. So my initial configuration was as you described above.
After the initial setup I added all sids with a small shell script,
copied from test050,

$LDAPMODIFY -x -D cn=config -H $HOST -w $CPW <<EOF
dn: cn=config
changetype: modify
replace: olcServerID
olcServerID: 1 $URL1
olcServerID: 2 $URL2

Now the contextCSN looks like
contextCSN: 20081022192158.873555Z#000000#001#000000
contextCSN: 20081022184543.202017Z#000000#002#000000
note the different sids 001, 002. ContextCSN, that is time + sid,
indicate which peer modified the database last.


Dieter KlÃnter | Systemberatung