May I ask what the problems are if the value is less? Do changes get lost if more changes were done than session log can hold while sync can't keep pace? Or does the server getting more changes simply block until there's spece in the sessionlog?
The server doesn't block anything. The session log is just a list of the IDs of the entries that changed. When a new one is added to the end of the list, the oldest one is dropped from the start of the list.
The reason it needs to be so large is to avoid the issues described in <https://www.openldap.org/its/index.cgi/?findid=8125>
Unfortunately, the session log (currently) does not persist across restarts of slapd, so it is still possible to hit ITS#8125 with "standard" syncrepl configurations. Thus one of the reasons I always advise to use delta-syncrepl.
--Quanah -- Quanah Gibson-Mount Product Architect Symas Corporation Packaged, certified, and supported LDAP solutions powered by OpenLDAP: <http://www.symas.com>