Java DNS Caching Solutions
As part of the CAS High Availability upgrade, CAS will be changing its IP address. This change will be carried out on the Campus DNS servers which will have their outbound TTL for the cas.ucdavis.edu hostname set to 10 minutes prior to the change.
However, as we discovered in the original High Availability rollout attempt, Java-based CAS clients do not automatically pick up the DNS changes. This is caused by an underlying security setting of the Java Virtual Machine that caches DNS resolutions permanently between restarts. This causes those clients to break after the DNS switch, as they do not update their IP address to the new setting.
Known Affected Clients
The Ja-Sig Java CAS client
Cold Fusion (cas_auth_dbcache and cas_auth_filecache)