Unfortunately, it seems that just one LDAP directory is not always enough. Sometimes we need to configure multiple LDAP directories as data source for the UME (User Management Engine); sometimes what we need is a high availability solution for our LDAP. Or even a mixture of both flavours:
Multiple LDAP data sources: This means that you have several LDAP directories (up to five) connected to the portal in parallel, so that the user data within the UME is coming from all of them.
High availability of 2 LDAP servers: This means that you have one LDAP server connected to the UME and, in case it is down for some reason, the UME fails over to another LDAP server which is also defined in the UME configuration.
High availability of multiple LDAP servers: This is a mixture of the previous scenarios. Here the UME obtains the user data from a group of LDAP directories which behave as described in the first point. Something to keep in mind here is that multiple data sources have different structures (otherwise you would not find the specific users as they would not be unique), so they cannot act as a high availability and a multiple LDAP server scenario at the same time!
Lets have a look here at the first configuration, the multiple-LDAP data source scenario:
Multiple LDAP directory servers as data source.Once we have created the new data source configuration file we have to upload it to the system. You can do this via the UM Configuration in the portal. Browse to find your XML file and upload it. After saving the new configuration, ensure that the LDAP parameters (ume.ldap.access.) in the “Direct Editing” tab are commented out, as these parameters should be configured in the XML file you have uploaded. After that, you will need to restart the J2EE.<br /><br />Note: The configuration for multiple LDAP servers does not apply for the high availability scenario.</p><p> </p><p>You can find further documentation on this at the SAP Library:<br />Example: Configuration of Multiple LDAP Data Sources
</p><p>And some good SAP notes to have a look at are:</p><p>673824 * – LDAP Issues for UME.
736471 – UME Configuration of multiple LDAP data sources.