Windl, Ulrich wrote:
Hi!
I always wondered about the scope within SyncRepl RIDs have to be unique:
The manpage says explicitly: within a consumer site.
- Per database
- Per server
- Within all servers
For a support case covering MMR replication including cn=config I got this response:
One cannot copy the config between machines. Syncrepl configuration includes the RID parameter. That RID must be UNIQUE on all servers. By copying the config, one now has two machines with the same RID.
That response is wrong. Of course a config can be copied between machines. The test suite test050 does exactly that, with replication.
I think its OK to do so, however. Slapd handles the situation where a server is asked to sync from itself correctly ARAIK.
We have three servers, says s1 (sid=1), s2 (sid=2), and s3 (sid=3). And there are three syncrepl statements making each server to syn from each of the three servers.
Now you're talking about SIDs, which are completely different from RIDs.
RIDs are purely informational; their main use is to disambiguate server log messages when there's more than one consumer configured in a server. They have no effect on the replication protocol at all.
So effectively s1 will sync from s2 and s3, s2 will sync from s1 and s3, and s3 will sync from s1 and s2 (each server ignoring the sync from itself).
The log message may be like this for s2:
slapd[1811445]: conn=1001 op=2 syncprov_matchops: skipping original sid 002
Am I correct, or is the supports answer correct?
Kind regards,
Ulrich Windl