Run time error at FTP polling

Error:

Sometimes when the SFTP polling is going on we are getting the below error. When we re-run the process its executes normally.

Exception:

java.sql.SQLException: Already closed.

Cause:The connection to the backend database has automatically been closed

Resolution:

The SQL already closed issue can be resolved by enabling the "testOnBorrow" and "validationQuery" property for connection pooling.These will ensure that the connection is active and is not closed.

Administer > Setup > Application Settings > Update System Properties > Performance Optimization > Backend Database > Backend Connection Pooling

In ‘validationQuery’ field you can provide a simple query to check that the connection that is used to backend is active. Below query can be used:

select * from dual