The database connectivity issues are either due to incorrect drivers or network connectivity. It's easy to identify using the simple telnet command test to check that your application(s) servers have allowed the network route to make the connection to the database server(s). One must perform telnet tests for all the possible client-server connections between the application and the database servers. In this scenario, all the application servers are clients and the database servers are servers for the telnet tests. It is a leading practice to perform this test for a newly deployed SOA composite application platform.
On the other hand, please pick the database driver library that works and delivers load sharing and auto recovery from failover and failback of a database server node for a database cluster with more than two server nodes. It is a leading practice to validate load sharing, failover, and failback scenarios to rollout for production runtime and perform this validation...