Deleted "subordinate" keyword, added slapo-glue doc

doc/man/man5/slapd.conf.5

@@ -1395,18 +1395,6 @@ backend database.  Multiple suffix lines can be given and at least one is
 required for each database definition.
 If the suffix of one database is "inside" that of another, the database
 with the inner suffix must come first in the configuration file.
-.TP
-.B subordinate
-Specify that the current backend database is a subordinate of another
-backend database. A subordinate database may have only one suffix. This
-option may be used to glue multiple databases into a single namingContext.
-If the suffix of the current database is within the namingContext of a
-superior database, searches against the superior database will be
-propagated to the subordinate as well. All of the databases
-associated with a single namingContext should have identical rootdns.
-Behavior of other LDAP operations is unaffected by this setting. In
-particular, it is not possible to use moddn to move an entry from
-one subordinate to another subordinate within the namingContext.
 .HP
 .hy 0
 .B syncrepl rid=<replica ID>

doc/man/man5/slapo-glue.5

+.TH SLAPO-GLUE 5 "RELEASEDATE" "OpenLDAP LDVERSION"
+.\" Copyright 2004 The OpenLDAP Foundation All Rights Reserved.
+.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
+.\" $OpenLDAP$
+.SH NAME
+slapo-glue \- Backend Glue overlay
+.SH SYNOPSIS
+ETCDIR/slapd.conf
+.SH DESCRIPTION
+The Backend Glue overlay can be used to glue multiple databases into a
+single namingContext. The overlay must be configured on the root database
+of the context, and any other databases must be explicitly configured
+as subordinates of the root database. All of the participating databases
+should have identical rootdns.
+
+All search and write operations will be intercepted by this overlay. Searches
+against the root database will be propagated to all the subordinates. Write
+operations will pass unaltered to the relevant target database. Note that
+any overlays on the root database configured before this overlay will fail
+to execute. As such, the glue overlay should always be the first overlay
+configured on the root database.
+
+.SH CONFIGURATION
+These
+.B slapd.conf
+options apply to the Backend Glue overlay.
+They should appear after the
+.B overlay
+directive and before any subsequent
+.B database
+directive.
+.TP
+.B glue-sub <suffix-DN> [async]
+Specify the suffix of a database to attach as a subordinate to the root
+database. The specified database must have already been configured. If the
+optional "async" keyword is supplied, searches against this database may
+be spawned in a separate thread to run concurrently with other operations.
+.SH FILES
+.TP
+ETCDIR/slapd.conf
+default slapd configuration file
+.SH SEE ALSO
+.BR slapd.conf (5).