Users Deleted in ActiveDirectory are logged in the AuditLog every Synchronisation.

If a user is deleted in the Active Directory, the User Deleted will be logged in the Audit Log every time the directory is synchronised.

Steps to reproduce:

• Install a clean JIRA instance.
• Create a new user directory Microsoft Active Directory Connector.
• Create a new user in the Active Directory.
• Synchronise the user Directory.
• Give the user the proper permission in JIRA to be able to log in and create a few issues.
• Create and comment in a few issues.
• Delete the user in Active Directory.
• Perform another Directory Synchronisation.
• Check the Audit Log.
• There will be an entry in the log regarding the user Deletion.
• Perform another synch, the deletion will be logged every time you perform a synch.
  
• The following appear in the logs during every synch:

  atlassian-scheduler-quartz1.clustered_Worker-2 INFO ServiceRunner     [atlassian.crowd.directory.DbCachingRemoteChangeOperations] deleting [ x] users
  atlassian-scheduler-quartz1.clustered_Worker-2 INFO ServiceRunner     [atlassian.crowd.directory.DbCachingRemoteChangeOperations] deleted [ x ] users in [ x ms ]
  

  For a single user it should not be a problem, but in some cases many users may have been deleted in active directory, and then every time the directory is synched new dozens of entries of user deletion are added to the audit log, making it difficult to find useful information in the log.