Соединение Oracle jdbc занимает много времени, затем java.sql.SQLRecoverableException: IO Error: Broken pipe

В моем приложении я использую подключение к Oracle. Иногда показывает ошибку Broken pipe, но не всегда.

1. Почему подключение занимает более 1 минуты (вызывает ошибку «Сломанная труба»)? БД и приложение на одном хосте.
2. Зачем переподключать 5-секундный цикл? Я предполагаю, что "Con time=30066" означает, что это было сделано 7 раз.

Пожалуйста, помогите и спасибо.

2016-08-05 10:00:40 (Con time=1041,  Qry time=12)
2016-08-05 10:00:43 (Con time=89,  Qry time=1)
2016-08-05 10:00:46 (Con time=65,  Qry time=7)
2016-08-05 10:00:49 (Con time=59,  Qry time=1)
2016-08-05 10:00:52 (Con time=58,  Qry time=1)
2016-08-05 10:00:55 (Con time=62,  Qry time=2)
2016-08-05 10:00:58 (Con time=100,  Qry time=1)
2016-08-05 10:01:01 (Con time=66,  Qry time=1)
2016-08-05 10:01:04 (Con time=60,  Qry time=1)
2016-08-05 10:01:08 (Con time=63,  Qry time=1)
2016-08-05 10:01:11 (Con time=68,  Qry time=0)
2016-08-05 10:01:14 (Con time=61,  Qry time=1)
...
2016-08-05 15:09:01 (Con time=30066,  Qry time=9)
2016-08-05 15:10:01 (Con time=65,  Qry time=11)
2016-08-05 15:11:06 (Con time=5059,  Qry time=11)
2016-08-05 15:12:07 (Con time=91,  Qry time=11)
2016-08-05 15:13:07 (Con time=73,  Qry time=12)
2016-08-05 15:14:07 (Con time=56,  Qry time=275)
2016-08-05 15:15:27 (Con time=20093,  Qry time=13)

java.sql.SQLRecoverableException: IO Error: Broken pipe
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:498)
        at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:553)
        at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:254)
        at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:32)
        at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:528)
        at java.sql.DriverManager.getConnection(DriverManager.java:322)
        at java.sql.DriverManager.getConnection(DriverManager.java:297)
        at DbCon.getDate(DbCon.java:325)
        at DbCon.main(DbCon.java:104)
Caused by: java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:103)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:147)
        at oracle.net.ns.DataPacket.send(DataPacket.java:210)
        at oracle.net.ns.NetOutputStream.flush(NetOutputStream.java:230)
        at oracle.net.ns.NetInputStream.getNextPacket(NetInputStream.java:321)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:268)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:190)
        at oracle.net.ns.NetInputStream.read(NetInputStream.java:107)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.readNextPacket(T4CSocketInputStreamWrapper.java:124)
        at oracle.jdbc.driver.T4CSocketInputStreamWrapper.read(T4CSocketInputStreamWrapper.java:80)
        at oracle.jdbc.driver.T4CMAREngine.unmarshalUB1(T4CMAREngine.java:1137)
        at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:350)
        at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:227)
        at oracle.jdbc.driver.T4CTTIoauthenticate.doOSESSKEY(T4CTTIoauthenticate.java:407)
        at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:416)
        ... 8 more



import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import oracle.jdbc.OracleConnection;

public class DbCon {


    /**JDBC Driver*/
    public static String JDBC_DRIVER = "oracle.jdbc.driver.OracleDriver";
    /**URL*/
    public static String JDBC_URL="jdbc:oracle:thin:XXXXXXXXXXXXXXX";

    public static void main(String[] args) {
        while(true){
            System.out.println(getDate());
            try {
                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }

    }


    /**
     * Get date for test
     * @return
     */
    public static String getDate() {
            Connection con = null;// SqlConnection
            ResultSet rs = null;// IDataReader
            PreparedStatement ps = null;
            String str = "";
            long timeCon = System.currentTimeMillis();
            try {

                    Class.forName(JDBC_DRIVER);
                    con = DriverManager.getConnection(JDBC_URL);
                    str = " (Con time="+(System.currentTimeMillis()-timeCon)+", ";
                    StringBuffer sbSql = new StringBuffer()
                                    .append("SELECT SYSDATE FROM DUAL");
                    ps = con.prepareStatement(sbSql.toString());
                    long timeQry = System.currentTimeMillis();
                    rs = ps.executeQuery();
                    while (rs.next()) {str = rs.getString(1) + str;}
                    str = str +" Qry time="+(System.currentTimeMillis()-timeQry)+")";
                    return str;
            } catch (SQLException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}
            finally {
                    if (rs != null) {try {rs.close();} catch (Exception ex) {ex.printStackTrace();}}
                    if (ps != null) {try {ps.close();} catch (Exception ex) {ex.printStackTrace();}}
                    if (con != null) {try {con.close();} catch (Exception ex) {ex.printStackTrace();}}
                    str =  " (Con time="+(System.currentTimeMillis()-timeCon)+")";
            }
            return str;
    }


}