CAS 3.5.2 appears to be loosing it's connection to SQL and partially crashing.

[Toby Archer]

We have two CAS 3.5.2 servers load. Both the app registry and the session tickets are stored in the database. Recently we have been having this issue where one of the tow CAS's seems to crash. If you get thrown on that CAS from the load balance you are met with a normal page, you login and get sent to an error page. It would seem that the cas server isn't saving the ticket into the database. I look at the logs and I get this error:

2018-08-29 07:10:49,602 WARN [com.mchange.v2.c3p0.impl.NewPooledConnection] - <[c3p0] A PooledConnection that has already signalled a Connection error is still in use!>

2018-08-29 07:10:49,602 WARN [com.mchange.v2.c3p0.impl.NewPooledConnection] - <[c3p0] Another error has occurred [ java.sql.SQLException: Invalid state, the Connection object is closed. ] which will not be reported to listeners!>
java.sql.SQLException: Invalid state, the Connection object is closed.
        at net.sourceforge.jtds.jdbc.JtdsConnection.checkOpen(JtdsConnection.java:1744)
        at net.sourceforge.jtds.jdbc.JtdsConnection.clearWarnings(JtdsConnection.java:2068)

The other cas server continues along just fine. We have made no changes to our servers in months, so this seems to have come out of nowhere. Has anyone seen this issue or know what is likely the problem?

~TA