That was it! Now before each dump of the lock table I do a em.flush and I am getting good output. I should be able to debug my deadlock issue now. Thanks!
> -----Original Message----- > From: Bergquist, Brett [mailto:bbergqu...@canoga.com] > Sent: Monday, February 04, 2013 15:00 > To: Derby Discussion; m...@the-kruegers.name > Subject: RE: SYSCS_DIAG.LOCK_TABLE keeps coming up enpty > > If this is using JPA, matbe you are not seeing any locking because the entity > manager is flushing is requests to the database engine only when the entity > bean methods is returned from and the transaction manager kicks in to > persist the changes. > > Try adding a "em.flush()" call on the entity manger which will force the > database changes to occur and then maybe you might see the lock table > populated. > > Just a thought. > > Brett > > > ________________________________________ > From: Mark Stephen Krueger [m...@the-kruegers.name] > Sent: Sunday, February 03, 2013 11:21 AM > To: derby-user@db.apache.org > Subject: SYSCS_DIAG.LOCK_TABLE keeps coming up enpty > > I'm trying to debug an issue with a deadlock with an EJB app running under > Glassfish 3.1.2.1. The app uses entity beans and the entity manager. I want > to view the lock table at various points so I wrote the following code. > The problem is everywhere I place a call to it, the lock table is always coming > back as empty (no rows). What am I missing? > > @Resource(mappedName="jdbc/myderbyjndi") > private DataSource dataSource; > > .. > > private void dumpLockTable() > { > try ( Connection connection = dataSource.getConnection() ) > { > PreparedStatement ps = connection.prepareStatement( "SELECT * > FROM SYSCS_DIAG.LOCK_TABLE" ); > ResultSet rs = ps.executeQuery(); > ResultSetMetaData rsmd = rs.getMetaData(); > int columns = rsmd.getColumnCount(); > StringBuilder sb = new StringBuilder(); > sb.append( "Lock Table\n" ); > while( rs.next() ) > { > for ( int col = 1; col <= columns; col++ ) > { > sb.append( rs.getString( col ) ); > sb.append( "\t|" ); > } > sb.append( "\n" ); > } > logger.info( sb.toString() ); > } > > catch ( SQLException sqle ) > { > logger.throwing( LOG_CLASS_NAME, "dumpLockTable", sqle ); > } > } > > > I believe this is Derby 10.8. > >
