Open LDAP vs apacheDS
I am working on scalable web application.I am planing to use LDAP for login authentication purpose.I am new to LDAP when I search about it I found two important implementations.1 Open LDAP and 2.Apache DS I search about performance comparison between two but i found very confusing benchmark results from various people.Some benchmark conclusion is performance is relatively same and few are saying openLDAP having greater performance as compare to Apache DS.
Answer
OpenLDAP and ApacheDS are great solutions that work across many platforms.
OpenLDAP is much more scalable and lightweight, however, keep in mind there are not that many tools for managing LDAP servers. OpenLDAP must be configured via command line using LDIF's. This is repetitive work that you have almost certainly have to have a domain administrator doing.
ApacheDS has a client solution and their config's are separated into XML files. ApacheDS is built on Java and yes you can expect there to be garbage collection.
Both ApacheDS approach scaling and their data backends similarly. In fact, in both cases it's the more manual way of clustering. You cluster for availability or you cluster for performance.
The previous responder mentioned OpenDJ which is not free to use in commercial settings by the way. Their license requires you purchase a license from them to use it commercially.