Execution of first request takes lot of time with JDBC OCI

Question

Hi,
We are having an application which connects to Oracle server(10g Enterprise Edition Release 10.2.0.4.0 64bit) using Oracle JDBC OCI driver(10.2.0.1.0 production (10g R2)).
Everything works fine.
But what we observed is randomly the first request to the server vai JDBC driver in a day takes lot of time, varies from 5-15 minutes.
If we execute the request again it executed immediately
What we observed while debugging is preparedStatement.executeQuery() is taking time.
We enabled logging at the JDBC driver layer and a snapshot isgiven below. Between T2CPreparedStatement.doDefineExecuteFetch () and T2CPreparedStatement.execute_for_rows () it takes 5 minutes. Any idea why it takes this much time and reason for it? Oracle driver is not throwing any exceptions
*4-apr-2011 4:00:01* oracle.jdbc.driver.T2CPreparedStatement doDefineExecuteFetch
FINE: T2CPreparedStatement.doDefineExecuteFetch ()
*4-apr-2011 4:05:12* oracle.jdbc.driver.T2CPreparedStatement executeForRows
FINE: T2CPreparedStatement.execute_for_rows () returns: void
Detailed jdbc log is below
-apr-2011 4:00:01 oracle.jdbc.driver.OracleStatement doExecuteWithTimeout
FINE: OracleStatement.doExecuteWithTimeout() needToPrepareDefineBuffer = false
4-apr-2011 4:00:01 oracle.jdbc.driver.PhysicalConnection needLine
FINE: PhysicalConnection.needLine()--no return
4-apr-2011 4:00:01 oracle.jdbc.driver.PhysicalConnection registerHeartbeat
FINE: PhysicalConnection.registerHeartbeat()
4-apr-2011 4:00:01 oracle.jdbc.driver.OracleStatement executeMaybeDescribe
FINE: OracleStatement.execute_maybe_describe() rowPrefetchChanged = false, needToParse = false, needToPrepareDefineBuffer = false, columnsDefinedByUser = false
4-apr-2011 4:00:01 oracle.jdbc.driver.T2CPreparedStatement executeForRows
FINE: T2CPreparedStatement.execute_for_rows (executed_for_describe = false)
4-apr-2011 4:00:01 oracle.jdbc.driver.T2CPreparedStatement doDefineExecuteFetch
FINE: T2CPreparedStatement.doDefineExecuteFetch ()
4-apr-2011 4:05:12 oracle.jdbc.driver.T2CPreparedStatement executeForRows
FINE: T2CPreparedStatement.execute_for_rows () returns: void
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleStatement executeMaybeDescribe
FINE: OracleStatement.execute_maybe_describe():return validRows = 1, needToPrepareDefineBuffer = false
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleStatement doExecuteWithTimeout
FINE: OracleStatement.doExecuteWithTimeout():return validRows = 1, needToPrepareDefineBuffer = false
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl next
FINE: OracleResultSetImpl.next(): closed=false
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl next
FINER: closed=false, statement.currentRow=-1, statement.totalRowsVisited=0, statement.maxRows=0, statement.validRows=1, statement.gotLastBatch=true
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl getString
INFO: OracleResultSetImpl.getString(columnIndex=1)
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl getString
INFO: OracleResultSetImpl.getString(columnIndex=2)
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl getString
INFO: OracleResultSetImpl.getString(columnIndex=3)
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl getTimestamp
INFO: OracleResultSetImpl.getTimestamp(columnIndex=4)
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl wasNull
INFO: OracleResultSetImpl.wasNull()
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl next
FINE: OracleResultSetImpl.next(): closed=false
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl next
FINER: closed=false, statement.currentRow=0, statement.totalRowsVisited=1, statement.maxRows=0, statement.validRows=1, statement.gotLastBatch=true
4-apr-2011 4:05:12 oracle.jdbc.driver.PhysicalConnection needLine
FINE: PhysicalConnection.needLine()--no return
4-apr-2011 4:05:12 oracle.jdbc.driver.T2CPreparedStatement closeQuery
FINE: T2CPreparedStatement.closeQuery ()
4-apr-2011 4:05:12 oracle.jdbc.driver.T2CPreparedStatement closeQuery
FINE: T2CPreparedStatement.closeQuery () returns: void
4-apr-2011 4:05:12 oracle.jdbc.driver.OracleResultSetImpl close
INFO: OracleResultSetImpl.close()
Regards
Sunil

Answer 1

Hi,
Thanks for the reply
- SQL may vary. Its not the same query which takes time always. The same query executed immediately(using another connection from pool) works perfectly
- If there is a failover or stale connection getting closed or timeout, will JDBC driver thhrows exdeption? I didn't see any exceptions in the driver logs. Is there anyway to identify whether failover or timeout is happening?
Some other points
- The application uses connection pooling. This means that connections are created in the beginning and kept in the pool. And it may be in the pool for 72 hours or , before this issue happens
- Application uses prepared statements and the statements are preapred and kept and re used later. So the query which take s more time might be prepared before 48 hours or so.
- This is not happening every day. Many times the pattern is , it happens after 60-72 hours after application is started.
Sunil