Weblogic JDBC driver problem with multithread environement

Hi, I encounter a problem with a Java application, during performance tests with many threads.
With Weblogic 8.1 and a driver JDBC type 4, the DB is SQL Server 2000

An exception occured on a RestultSet.next().
The SQL error message is not explicit

Code:

java.sql.SQLException: [BEA][SQLServer JDBC Driver][SQLServer] weblogic.jdbc.base.BaseExceptions.createException(Unknown Source) weblogic.jdbc.base.BaseExceptions.getException(Unknown Source) weblogic.jdbc.sqlserver.tds.TDSRequest.processErrorToken(Unknown..) weblogic.jdbc.sqlserver.tds.TDSRequest.processReplyToken(Unknown..) weblogic.jdbc.sqlserver.tds.TDSRPCRequest.processReplyToken(..) weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.processReplyToken() weblogic.jdbc.sqlserver.tds.TDSRequest.processReply(..) weblogic.jdbc.sqlserver.tds.TDSRequest.getRow(..) weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.getRow(..) weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.fetchNext(..) weblogic.jdbc.sqlserver.SQLServerImplResultSetServerSideCursor.next(Unknown Source) weblogic.jdbc.base.BaseResultSet.next(Unknown Source) weblogic.jdbc.wrapper.ResultSet_weblogic_jdbc_base_BaseResultSet.next

A various percentage of threads between 50% and 90% gets an error below, at

Code:

result1.next()

Code:

try{  pstmt1= contexte.getConnection().prepareStatement(SELECT_EQUIPE);             pstmt1.setLong(1, ...);             pstmt1.setString(2, ...);             result1 = pstmt1.executeQuery();             ...             while (result1.next()){                 ...             }             result1.close();             fermerPreparedStatement(pstmt1,voi);         } finally {             result1.close();             fermerPreparedStatement(pstmt1,voi);         }

Connections are opened and closed by the framework, we only handle here the statements and resultset. Other accesses to the DB in a similar way work fine elsewhere in the application but here it throws this exception.
The pool is large enough (100 to 150 connections, for 40 threads), it runs with selectMethod=cursor, row prefetched enable.

Any information about such an error ? I miss good ideas

GoJ wrote:

 > Hi, I encounter a problem with a Java application, during performance
 > tests with many threads.
 > With Weblogic 8.1 and a driver JDBC type 4, the DB is SQL Server 2000
 >
 > An exception occured on a RestultSet.next().
 > The SQL error message is not explicit
 >
 > java.sql.SQLException: [BEA][SQLServer JDBC Driver][SQLServer]
 > weblogic.jdbc.base.BaseExceptions.createException(Unknown Source)
 > weblogic.jdbc.base.BaseExceptions.getException(Unknown Source)
 > weblogic.jdbc.sqlserver.tds.TDSRequest.processErrorToken(Unknown..)
 > weblogic.jdbc.sqlserver.tds.TDSRequest.processReplyToken(Unknown..)
 > weblogic.jdbc.sqlserver.tds.TDSRPCRequest.processReplyToken(..)
 > weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.processReplyTok
 > en()
 > weblogic.jdbc.sqlserver.tds.TDSRequest.processReply(..)
 > weblogic.jdbc.sqlserver.tds.TDSRequest.getRow(..)
 > weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.getRow(..)
 > weblogic.jdbc.sqlserver.tds.TDSRPCCursorExecuteRequest.fetchNext(..)
 > weblogic.jdbc.sqlserver.SQLServerImplResultSetServerSideCursor.next(Un
 > known
 > Source)
 > weblogic.jdbc.base.BaseResultSet.next(Unknown Source)
 > weblogic.jdbc.wrapper.ResultSet_weblogic_jdbc_base_BaseResultSet.next
 >
 >
 > A various percentage of threads between 50% and 90% gets an error
 > below, at result1.next()
 >
 >
 > try{
 > pstmt1= contexte.getConnection().prepareStatement(SELECT_EQUIPE);
 > pstmt1.setLong(1, ...);
 > pstmt1.setString(2, ...);
 > result1 = pstmt1.executeQuery();
 > ...
 > while (result1.next()){
 > ...
 > }
 > result1.close();
 > fermerPreparedStatement(pstmt1,voi);
 > } finally {
 > result1.close();
 > fermerPreparedStatement(pstmt1,voi);
 > }
 >
 > Connections are opened and closed by the framework, we only handle
 > here the statements and resultset. Other accesses to the DB in a
 > similar way work fine elsewhere in the application but here it throws
 > this exception.
 > The pool is large enough (100 to 150 connections, for 40 threads), it
 > runs with selectMethod=cursor, row prefetched enable.
 >
 > Any information about such an error ? I miss good ideas

Hi. BEA also has newsgroups that are more tailored to WebLogic JDBC...
You may be suffering from a non-thread-safety issue in your code.
Are you absolutely sure that no two threads are getting the same
connection?
The code is not how a typical symmetrical call sequence should be.
It should be like:

Connection c = null; // Make this a *local method* variable!
try {
c = myDataSource.getConnection(); // only this thread gets or uses c
// Statement is local to try block
PreparedStatement pstmt1= c.prepareStatement(SELECT_EQUIPE);
pstmt1.setLong(1, ...);
pstmt1.setString(2, ...);
ResultSet result1 = pstmt1.executeQuery();
...
while (result1.next()) {
}
result1.close();
pstmt1.close();
}
finally {
c.close(); // put back into pool, close in any case, ASAP
}

Joe Weinstein at BEA

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