addpartial Overlay README DESCRIPTION This package contains an OpenLDAP overlay called "addpartial" that intercepts add requests, determines if the entry exists, determines what attributes, if any, have changed, and modifies those attributes. If the entry does not exist, the add request falls through and proceeds normally. If the entry exists but no changes have been detected, the client receives LDAP_SUCCESS (I suppose it is debatable what to do in this case, but this is the most clean for my use. The LDAP_SUCCESS lets me know that the entry I sent slapd == the entry already in my slapd DB. Perhaps this behavior should be configurable in the future). When a change is found, the addpartial overlay will replace all values for the attribute (if an attribute does not exist in the new entry but exists in the entry in the slapd DB, a replace will be done with an empty list of values). Once a modify takes place, the syncprov overlay will properly process the change, provided that addpartial is the first overlay to run. Please see the CAVEATS for more specifics about this. The addpartial overlay makes it easy to replicate full entries to a slapd instance without worrying about the differences between entries or even if the entry exists. Using ldapadd to add entries, the addpartial overlay can compare about 500 records per second. The intent of the addpartial overlay is to make it easy to replicate records from a source that is not an LDAP instance, such as a database. The overlay is also useful in places where it is easier to create full entries rather than comparing an entry with an entry that must be retrieved (with ldapsearch or similar) from an existing slapd DB to find changes. The addpartial overlay has been used in production since August 2004 and has processed millions of records without incident. BUILDING A Makefile is included, please set your OPENLDAP_SRC directory properly. INSTALLATION After compiling the addpartial overlay, add the following to your slapd.conf: ### slapd.conf ... moduleload /path/to/addpartial-overlay.so ... # after database directive... # this overlay should be the last overlay in the config file to ensure that # it properly intercepts the add request overlay addpartial ... ### end slapd.conf CAVEATS - In order to ensure that addpartial does what it needs to do, it should be the last overlay configured so it will run before the other overlays. This is especially important if you are using syncrepl, as the modify that addpartial does will muck with the locking that takes place in the syncprov overlay. --- Copyright 2004-2012 The OpenLDAP Foundation. Portions Copyright (C) Virginia Tech, David Hawes. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted only as authorized by the OpenLDAP Public License. A copy of this license is available in file LICENSE in the top-level directory of the distribution or, alternatively, at http://www.OpenLDAP.org/license.html.