This is important for freeing network resources on heavily laden web-app servers as well as the LDAP servers they point at. I had to add <% contextName.close(); %> to the end of my jsp page in order to do a timely close of the connection to an LDAP resource. In my Java code that uses JNDI and LDAP, I just use contextName.close() in the finally clause so as not to forget :-)
*** This bug has been marked as a duplicate of 23363 ***