I just raised a Jira issue (https://issues.apache.org/jira/browse/DIRSERVER-1902) concerning failures when multiple requests are made to a directory concurrently. As per the Jira I see LDAP Error Code 49, 80 and 1 that appear to be related to a ConcurrentModificationException in ServerEntryUtils.
I have marked the bug as critical, however It may actually be a blocker. Please let me know if you need any further information to help with analysis, it would be a pleasure to help. Many thanks, Paul
