Hi Mukhtar,
As David Pointed out , you can achive SSO with AD keeping the UME as ABAP.
But in case you want to change it to LDAP Datasource, it is a 2 step process.
1) You have to change the Datasource to Database ( Using the Visual Administrator )
Change the property ume.persistence.data_source_configuration of Service com.sap.security.core.ume.service to dataSourceConfiguration_database_only.xml
2) SAVE
3) Restart the AS Java
4) Now , when you navigate to UME Configuration , you shall be able to see the LDAP options in the Drop Down.
Regards,
Ashish .A. Poojary