I am getting below error while executing SQOOP import command : ERROR manager.SqlManager: Error executing statement: java.sql.SQLRecoverableException: IO Error: The Network Adapter could not establish the connection
Your --connect URL does not seem to be correct.
--connect jdbc:oracle:thin://<ip address>:1521/app
Change it to something like following
--connect jdbc:oracle:thin:@//<ip address>:1521/app
Also it will be best to check if the oracle DB listener is started listening properly on port 1521 or not?
It will be also good to check if the port is accessible fine from the sqoop client host:
telnet <oracle_ipaddress> 1521
If app is not a defined service for the TNS listener but the instance id, use this URL format
Also, make sure you can connect to the Oracle instance from the all the client nodes (typically) as the sqoop mappers will run across the cluster.
See if the listener and the database are initiated. I just started the listener (lsnrctl start) and the database (sqlplus / as sysdba and startup) and it worked.