CAS Error principal cannot be null

[Juan Quintanilla]

Hi,

We are running into an interesting issue when load testing our CAS implementation. It seems that after about 3 hours of load testing we begin to encounter the following error:

2019-05-16 12:57:30,074 WARN [org.apereo.cas.web.flow.resolver.impl.InitialAuthenticationAttemptWebflowEventResolver] - <'principal' cannot be null.

Check the correctness of @Audit annotation at the following audit point: execution(public org.apereo.cas.authentication.Authentication org.apereo.cas.authentication.AbstractAuthenticationManager.authenticate(org.apereo.cas.authentication.AuthenticationTransaction))>

java.lang.IllegalArgumentException: 'principal' cannot be null.

Once we encounter this error we cannot log into CAS anymore we are just left on the login page. After a restart of Tomcat it start working again. When checking the logs we can see that the authentication piece is working as the attributes are being returned and the user is authenticated.

2019-05-16 12:57:29,855 DEBUG [org.apereo.cas.authentication.LdapAuthenticationHandler] - <Created LDAP principal for id [johnd] and [11] attributes>

2019-05-16 12:57:29,855 DEBUG [org.apereo.cas.authentication.AbstractAuthenticationManager] - <Authentication handler [LdapAuthenticationHandler] successfully authenticated [johnd]>

We are running CAS 5.1.9 with Tomcat 8.5.41, Java 8 update 211, and hazelcast for ticket registry we have also tested with Mongodb running on the webserver and we encounter the same issue.  I have also encountered the same issue when testing CAS 5.3. 

We have checked Memory and it doesn't seem to be the case were it runs out of memory.

If we have mongodb running on a different server then we don't encounter the issue the same goes for an Oracle Database. It only happens when running on the same server as the CAS Application.

Has anyone encountered anything similar to this?

Thanks!

___________________
Juan Quintanilla