There was a slight change in the JDBC format, so you must edit the tpf.properties file that you usually find under:
/usr/local/queuemetrics/tomcat/webapps/wombat/WEB-INF.
Look for the tpf.properties file and replace the entry:
JDBC_DRIVER=com.mysql.jdbc.Driver
JDBC_URL=jdbc:mysql://127.0.0.1/wombat?user=wombat&password=dials&useUnicode=true&characterEncoding=UTF-8
With:
JDBC_DRIVER=org.mariadb.jdbc.Driver
JDBC_URL=jdbc:mariadb://127.0.0.1/wombat?user=wombat&password=dials&autoReconnect=true
See also the Upgrading section of our manual for the changes, and then restart.