I did only enable it after the issue happened. Also increased the sessionlog on the provider at the same time, not sure if that is a lot or little, but the provider will be managing a lot of info and clients.
I could now actually see more sync entries in the logs.
Firstly the entry I shared before and then hundreds of the following:
do_syncrep2: rid=000 NEW_COOKIE: rid=000,csn=20240724114028.866106Z#000000#000#000000 Jul 24 11:40:28 Consumer slapd[1466367]: slap_queue_csn: queueing 0x7fe8f0109f10 20240724114028.866106Z#000000#000#000000 Jul 24 11:40:28 Consumer slapd[1466367]: slap_graduate_commit_csn: removing 0x7fe8f0109f10 20240724114028.866106Z#000000#000#000000
Followed by hundreds more of the following, but seems to be only listing the groups, not the ou=users. Also found it a bit weird, there is only a single user that was synced (or was not removed as the others), but no sync log about him.
do_syncrep2: rid=000 cookie=rid=000,csn=20240724114029.713635Z#000000#000#000000 Jul 24 11:40:29 Consumer slapd[1466367]: syncrepl_message_to_entry: rid=000 DN: cn=group,ou=Groups,dc=test=net, UUID: 75407828-d95f-103e-8539-f354611c95ec Jul 24 11:40:29 Consumer slapd[1466367]: syncrepl_entry: rid=000 LDAP_RES_SEARCH_ENTRY(LDAP_SYNC_MODIFY) csn=20240724114029.713635Z#000000#000#000000 tid 0x7fe8fa7fe640 Jul 24 11:40:29 Consumer slapd[1466367]: syncrepl_entry: rid=000 be_search (0) Jul 24 11:40:29 Consumer slapd[1466367]: syncrepl_entry: rid=000 cn=group,ou=Groups,dc=test=net Jul 24 11:40:29 Consumer slapd[1466367]: slap_queue_csn: queueing 0x7fe8ec11f4e0 20240724114029.713635Z#000000#000#000000
And after those, hundreds more of these:
do_syncrep2: rid=000 LDAP_RES_INTERMEDIATE - NEW_COOKIE Jul 24 11:40:31 Consumer slapd[1466367]: do_syncrep2: rid=000 NEW_COOKIE: rid=000,csn=20240724114030.988885Z#000000#000#000000 Jul 24 11:40:31 Consumer slapd[1466367]: slap_queue_csn: queueing 0x7fe8ec108eb0 20240724114030.988885Z#000000#000#000000
It is doing this every 20 minutes, with some do_syncrepl: rid=000 rc -1 retrying (2 retries left) in between, Network not too stable, but I saw no error messages or even warnings.
Hopefully this info helps more.
BR, José Pereira