How to correctly monitor a Database Oracle

I did a new test modifying the connection as you suggested and now this is waht i get:

2015-07-10 11:30:28.737: jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp(H OST=172.20.1.73)(PORT=1527))(CONNECT_DATA=(SERVICE_NAME=PRODM1))(SERVER=dedicate d))(Thread-328123): DB DriverManager.getConnection failed: "NL Exception was gen erated" java.sql.SQLException: NL Exception was generated at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:412) at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java: 531) at oracle.jdbc.driver.T4CConnection.(T4CConnection.java:221) at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtensio n.java:32) at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:503) at java.sql.DriverManager.getConnection(DriverManager.java:579) at java.sql.DriverManager.getConnection(DriverManager.java:221) at com.f5.eav.DB_Pinger.db_Connect(DBDaemon.java:1052) at com.f5.eav.DB_Pinger.db_Ping(DBDaemon.java:996) at com.f5.eav.MonitorWorker.run(DBDaemon.java:501) at java.lang.Thread.run(Thread.java:722) Caused by: oracle.net.ns.NetException: NL Exception was generated at oracle.net.resolver.AddrResolution.resolveAddrTree(AddrResolution.jav a:614) at oracle.net.resolver.AddrResolution.resolveAndExecute(AddrResolution.j ava:411) at oracle.net.ns.NSProtocol.establishConnection(NSProtocol.java:672) at oracle.net.ns.NSProtocol.connect(NSProtocol.java:237) at oracle.jdbc.driver.T4CConnection.connect(T4CConnection.java:1042) at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:301) ... 10 more

Any ideas where should i look for the problema or what can i do?