Gunnar Bostrom [http://community.jboss.org/people/gunnarbos] created the discussion "OracleValidConnectionChecker Unexpected error in pingDatabase" To view the discussion, visit: http://community.jboss.org/message/599108#599108 -------------------------------------------------------------- Hi, We use JBoss 5.1.0.GA and java 1.6 and run in to trouble with org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker. 08:23:24,519 WARN  [org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker] (http-0.0.0.0-8080-1) Unexpected error in pingDatabase java.lang.IllegalArgumentException: object is not an instance of declaring class This started to happen when I added <!-- sql to call on an existing pooled connection when it is obtained from                               pool - the OracleValidConnectionChecker is prefered -->                     <check-valid-connection-sql>select 1 from dual</check-valid-connection-sql>                     <valid-connection-checker-class-name>org.jboss.resource.adapter.jdbc.vendor.OracleValidConnectionChecker                     </valid-connection-checker-class-name> to our oracle-ds.xml because we must check if the connection in the pool is valid. The log says warning, but is the check done and a new connection created if the check failed? Regards Gunnar -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/599108#599108] Start a new discussion in Datasource Configuration at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]