LDAP UserDN cache full

I recently upgraded to version 4.2.3 of Openfire and noticed a recurring message in the logs:

2018.04.03 13:13:12 WARN [socket_c2s-thread-17]: org.jivesoftware.util.cache.DefaultCache - LDAP UserDN cache was full, shrinked to 90% in 0ms.
2018.04.03 13:13:20 WARN [socket_c2s-thread-10]: org.jivesoftware.util.cache.DefaultCache - UserDN LDAP cache was full, shrinked to 90% in 1ms.

I was not aware of this LDAP UserDN cache in previous versions and from what I saw the same is always reaching the limit.

Is there a way to increase the LDAP UserDN cache? If yes, what property to change?

The default size is 262144 bytes.

Set the system property cache.LDAPUserDN.size to something larger, if you want.

However, it’s only a cache, so it’s not essential, but you may see a performance improvement.