Resultset.next hangs waiting for socketread()

Question

Hi All,
I am running an application which is trying to fetch a set of records using jdbc resultset but , sometimes, it hangs on the socketread and I am not sure what is the cause..Please help:
Below is the piece of code and parameters are:
start=1
iBreakingLimit=30 when it hangs
QueryTimeout=60 sec
limit=60
Hangs at:
SocketInputStream.socketRead()
OracleResultSet.close_or_fetch_from_next(boolean)
ScrollableResultSet.next()
dbStatement=dbConnection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
                                      if(start>1)
                    rs.absolute(start-1);
               int iBreakingLimit=0;
               while (rs.next())
                    ++iBreakingLimit;
                    if(limit>0 && iBreakingLimit>limit)
                         break;
                                  }Edited by: Amer on Apr 15, 2009 7:49 AM
Edited by: Amer on Apr 15, 2009 7:50 AM
Edited by: Amer on Apr 15, 2009 7:50 AM
Edited by: Amer on Apr 15, 2009 7:51 AM

Answer 1

Hi Again,
I wrote a sample class to test the connection and my select statement and I was able to reproduce it outside the application. This class has no update at all and it never returns (hangs at iteration number 7 for the first loop).... Another test (removing timeout set which I think it is not related) shows that it stops at Iteration 4 breaking limit 40 (so it is random).. Also, I tried with TRANSACTION_SERIALIZABLE and got same behavior . THIS does NOT happen with db2 driver using same sample.. Please help!!
package com.udm.core.test;
import java.sql.*;
public class JDBCTest
     public static void main(String s[])
          JDBCTest t = new JDBCTest();
          try
               for(int i=0;i<30;i++)
                    System.out.println("Call ="+i);
                    t.testme();
          catch(Exception e)
               e.printStackTrace();
     public void testme() throws Exception
          String sUrl="jdbc:oracle:thin:";
          String sServer="xxxxxxxxxx";
          String sPort="xxxx";
          String sService="xxxxx";
          String sDriver = "oracle.jdbc.OracleDriver";
          String sUserName="xxxx";
          String sPassword="xxxxxx";
          String sSQL="select about 270 fields from table (pure select statement)";     
          Class<?> cDriverClass=Class.forName(sDriver);
          Driver dDriverObject=(java.sql.Driver)cDriverClass.newInstance();
          DriverManager.registerDriver (dDriverObject);
          String sServiceUrl=sUrl+"@"+sServer+":"+sPort+":"+sService;
          Connection dbConnection=DriverManager.getConnection (sServiceUrl,sUserName,sPassword);
          dbConnection.setAutoCommit(false);
          dbConnection.setTransactionIsolation(Connection.TRANSACTION_READ_COMMITTED);
          Statement dbStatement =dbConnection.createStatement();
          dbStatement.setQueryTimeout(60);
          ResultSet rs=dbStatement.executeQuery(sSQL);
          int iBreakingLimit=0;
          int limit=200;
          while (rs.next())
               ++iBreakingLimit;
               if(limit>0 && iBreakingLimit>limit)
                    break;
               System.out.println("\tInside loop iBreakingLimit="+iBreakingLimit);
          rs.close();
          dbStatement.close();
}Thread dump:
Call =7
Full thread dump Java HotSpot(TM) Client VM (1.5.0_16-b02 mixed mode):
"OracleTimeoutPollingThread" daemon prio=10 tid=0x0ac89868 nid=0x1380 waiting on condition [0x0af0f000..0x0af0fbe8]
at java.lang.Thread.sleep(Native Method)
at oracle.jdbc.driver.OracleTimeoutPollingThread.run(OracleTimeoutPollingThread.java:158)
"Low Memory Detector" daemon prio=6 tid=0x00a955e0 nid=0xeb4 runnable [0x00000000..0x00000000]
"CompilerThread0" daemon prio=10 tid=0x00a942f8 nid=0xb30 waiting on condition [0x00000000..0x0abcfa48]
"Signal Dispatcher" daemon prio=10 tid=0x00a93660 nid=0x172c waiting on condition [0x00000000..0x00000000]
"Finalizer" daemon prio=8 tid=0x00a8a440 nid=0x12f0 in Object.wait() [0x0ab4f000..0x0ab4fa68]
at java.lang.Object.wait(Native Method)
- waiting on <0x02fd5d00> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:120)
- locked <0x02fd5d00> (a java.lang.ref.ReferenceQueue$Lock)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:136)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:159)
"Reference Handler" daemon prio=10 tid=0x00a89008 nid=0xa58 in Object.wait() [0x0ab0f000..0x0ab0fae8]
at java.lang.Object.wait(Native Method)
- waiting on <0x02fd5d88> (a java.lang.ref.Reference$Lock)
at java.lang.Object.wait(Object.java:474)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116)
- locked <0x02fd5d88> (a java.lang.ref.Reference$Lock)
"main" prio=6 tid=0x00036af8 nid=0x1450 runnable [0x0007f000..0x0007fc3c]
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at oracle.net.ns.Packet.receive(Unknown Source)
at oracle.net.ns.DataPacket.receive(Unknown Source)
at oracle.net.ns.NetInputStream.getNextPacket(Unknown Source)
at oracle.net.ns.NetInputStream.read(Unknown Source)
at oracle.jdbc.driver.T4CMAREngine.getNBytes(T4CMAREngine.java:1520)
at oracle.jdbc.driver.T4CMAREngine.unmarshalNBytes(T4CMAREngine.java:1490)
at oracle.jdbc.driver.T4CMAREngine.unmarshalBuffer(T4CMAREngine.java:2004)
at oracle.jdbc.driver.T4CMAREngine.unmarshalCLR(T4CMAREngine.java:1791)
at oracle.jdbc.driver.T4CMAREngine.unmarshalCLR(T4CMAREngine.java:1925)
at oracle.jdbc.driver.T4CMAREngine.unmarshalDALC(T4CMAREngine.java:2347)
at oracle.jdbc.driver.T4C8TTIuds.unmarshal(T4C8TTIuds.java:134)
at oracle.jdbc.driver.T4CTTIdcb.receiveCommon(T4CTTIdcb.java:154)
at oracle.jdbc.driver.T4CTTIdcb.receive(T4CTTIdcb.java:114)
at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:703)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
at oracle.jdbc.driver.T4CPreparedStatement.executeForDescribe(T4CPreparedStatement.java:799)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1039)
at oracle.jdbc.driver.T4CPreparedStatement.executeMaybeDescribe(T4CPreparedStatement.java:839)
at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1124)
at oracle.jdbc.driver.OracleStatement.executeQuery(OracleStatement.java:1272)
- locked <0x02b2f5b0> (a oracle.jdbc.driver.T4CPreparedStatement)
- locked <0x02b18e30> (a oracle.jdbc.driver.T4CConnection)
at com.udm.core.test.JDBCTest.testme(JDBCTest.java:50)
at com.udm.core.test.JDBCTest.main(JDBCTest.java:15)
"VM Thread" prio=10 tid=0x00a86540 nid=0xfec runnable
Edited by: Amer on Apr 17, 2009 6:45 AM
Edited by: Amer on Apr 17, 2009 6:45 AM
Edited by: Amer on Apr 17, 2009 6:47 AM
Edited by: Amer on Apr 17, 2009 6:48 AM
Edited by: Amer on Apr 17, 2009 6:58 AM
Edited by: Amer on Apr 17, 2009 7:05 AM