Torsten Schlabach (Tascel eG) wrote:
Hi Howard!
MirrorMode relies on an external frontend to direct all updates to a single provider. There is no difference within the OpenLDAP code between MirrorMode and MultiMaster; the difference is entirely external, based on your deployment.
So when you say: "We recommend not to use MMR", you're not saying don't use code section X of openldap but use code section Y, but you're basically saying: Do not send different updates to different providers at the same time, right?
Yes.
In other words: If I would configure MMR between say 3 nodes but I would make sure that only one of them will receive updates at a time while on the other two there will only be read operations, then I have MirrorMode?
Is that right?
Yes.
for new updates; in refreshAndPersist mode it will keep an LDAP session open and receive updates as they occur.
Could I query a provider to show me the current open sessions held by the consumers?
You can get a look at open sessions from cn=monitor but I don't think the syncrepl sessions are highlighted in any particular way. What are you expecting this to tell you?
When is refreshOnly and when is refreshAndPersist recommended?
We don't make any particular recommendation. Some sites want "instantaneous" replication; for them refreshAndPersist is the obvious choice. Other sites only need coarse synchronization, or don't want to have long-lived LDAP sessions open all the time. So they choose refreshOnly. On my G1 phone my slapd is configured in refreshOnly syncing my home addressbook (with a 12 hour refresh interval) because I just don't make changes often enough for it to matter.
I was always confused in the documentation, as it says: sncrepl is entirely a client side technology and then it says you have the option to either pull or push updates. Now this becomes a bit clearer to me. Thanks for that.