B. Upgrading from 2.3.x
The following sections attempt to document the steps you will need to take in order to upgrade from the latest 2.3.x OpenLDAP version.
The normal upgrade procedure, as discussed in the Maintenance section, should of course still be followed prior to doing any of this.
Quite a few olc* attributes have now become obsolete, if you see in your logs entries like below, just remove them from the relevant ldif file.
olcReplicationInterval: value #0: <olcReplicationInterval> keyword is obsolete (ignored)
Search operations now require "search" privileges on the "entry" pseudo-attribute of the search base. While upgrading from 2.3.x, make sure your ACLs grant such privileges to all desired search bases.
For example, assuming you have the following ACL:
access to dn.sub="ou=people,dc=example,dc=com" by * search
Searches using a base of "dc=example,dc=com" will only be allowed if you add the following ACL:
access to dn.base="dc=example,dc=com" attrs=entry by * search
Note: The slapd.access(5) man page states that this requirement was introduced with OpenLDAP 2.3. However, it is the default behavior only since 2.4.
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