I'm having some problems understanding the subtleties of MirrorMode vs MultiMaster configurations. Any help with the following questions would be helpful:
1) It looks like the only real difference between a MirrorMode and Multimaster configuration is whether or not the RIDs are different. In MirrorMode both sides have the same rid, in Multimaster they are different. Is that so?
2) Passing through the code, "MirrorMode" is really "Single Master" and MultiMaster is just "not Single Master". But the code path to determine whether it is single master or not confuses me. How does slapd actually determine this?
3) For MultiMaster, the docs show using syncrepl to replicate cn=config and the directory (or directories if you have more than one) independently. Is it really necessary to replicate cn=config if the configuration isn't changing? (What I'm really looking for here is to find out if there is state information in cn=config thats being used or if its simply a good idea to ensure the configs are the same by using syncrepl.)
Thanks,
benr.
Hi Ben!
My understanding of this (based on an earlier discussion here on this list) is that MultiMaster is more of a concept than a technology.
IIRC, then you have to set MirrorMode to true in MultiMaster as well.
Regards, Torsten
On Mon, 16 May 2011 01:24:45 -0700, Ben Rockwood benr@cuddletech.com wrote:
I'm having some problems understanding the subtleties of MirrorMode vs MultiMaster configurations. Any help with the following questions would be helpful:
- It looks like the only real difference between a MirrorMode and
Multimaster configuration is whether or not the RIDs are different. In MirrorMode both sides have the same rid, in Multimaster they are different. Is that so?
- Passing through the code, "MirrorMode" is really "Single Master" and
MultiMaster is just "not Single Master". But the code path to determine whether it is single master or not confuses me. How does slapd actually determine this?
- For MultiMaster, the docs show using syncrepl to replicate cn=config
and the directory (or directories if you have more than one) independently. Is it really necessary to replicate cn=config if the configuration isn't changing? (What I'm really looking for here is to find out if there is state information in cn=config thats being used or if its simply a good idea to ensure the configs are the same by using syncrepl.)
Thanks,
benr.
openldap-technical@openldap.org