artifactory 5.2: sporadic access denied for all AD users

Question

The third time in two weeks that we're having login denied errors for all users on the web ui. The login is denied for about 20 minutes, then it works again. Is it possible to set a debug level for the login issues?

root@f71cca9d92a7:/opt/jfrog/artifactory/logs# tail -n 100 access.log | grep 10.3.9.15 
2017-06-16 08:18:42,794 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:18:58,465 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:19:20,921 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:21:06,299 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:21:32,129 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:24:02,056 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:24:21,542 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:31:58,153 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:33:21,606 [DENIED LOGIN]  for NA/10.3.9.15.
2017-06-16 08:38:30,398 [ACCEPTED LOGIN]  for mwlo/10.3.9.15.
2017-06-16 08:40:44,938 [ACCEPTED LOGIN]  for mwlo/10.3.9.15.

AD Search Filter: (&(objectCategory=Person)(sAMAccountName={0}) (memberOf=CN=artifactory-users,DC=company,DC=de))

Answer 1

I haven't upgraded artifactory as we come from nexus and it's our first installation. I have increased artifactory's xmx. Error has disappeared.