Sonar with ldap plugin does not use LDAP without domain prefix - ldap

Question

I'm using sonar 5.6 LTS with LDAP plugin 2.1.0.
The basic LDAP configuation is working fine. Sonar can connect to LDAP (in my case active directory). sonar.log:
Test LDAP connection on ldaps://ldap.mycompany:636: OK
My user mapping is
ldap.user.baseDn=OU=Users,OU=Accounts,DC=mycompany
ldap.user.request=(&(objectClass=user)(sAMAccountName={login}))
When I try to login with mycompany\tobi sonar logs:
DEBUG web[o.s.p.l.LdapUsersProvider] Requesting details for user mycompany\tobi
...
DEBUG web[o.s.p.l.LdapUsersProvider] User mycompany\tobi not found in <default>
This makes sense as sAMAccountName contains the value tobi and not mycompany\tobi. But when using just tobi as login, sonarqube does not connect to LDAP for authentication. I just get "Authentication failed" and the log file contains only
DEBUG web[http] POST /sonar/sessions/login | time=235ms
Any ideas why sonarqube does not always use LDAP? Thanks, Tobi

Answer 1

Thanks to Godin, I've finally found the answer:
The root cause is that I had a local account with the same login credentials before using LDAP. When removing users using the web interface, they are not removed permanently from the database. Instead, they are just deactivated.
I connected to the (postgresql) database and in the users table there were still all old local accounts. So I just changed the login column of all deprecated local accounts with
UPDATE users SET login='username_local' WHERE login='username'
As those accounts are deactivated, they cannot be used to login into sonarqube but should not be removed as some other tables might still have references to them.